Name: Examination of Rapid Dopamine Dynamics with Fast Scan Cyclic Voltammetry During Intra-oral Tastant Administration in Awake Rats (Video) | JoVE Journal
Uploaded: 2015-08-12T13:00:00.000+00:00
Duration: 10 min 44 s
Description: Learn fast scan cyclic voltammetry for measuring rapid dopamine dynamics in awake rats during intra-oral tastant administration. This method enables precise neurotransmitter detection in reward processing studies.

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5 minutes

Research reported in this publication was supported by an NSF Graduate Research Fellowship (RJW) and by the National Institute on Drug Abuse of the National Institutes of Health and FDA Center for Tobacco Products (CTP) under Award Number P50DA036151(EJN and NAA). The content is solely the responsibility of the authors and does not necessarily represent the official view of the National Institutes of Health.

All experiments were conducted according to the National Institutes of Health (NIH) Guide for the Care and Use of Laboratory Animals and were approved by the Yale University Institutional Animal Care and Use Committee (IACUC).
1) Pre-surgical Preparations
<ol>
	<li>Oral solution preparation
	<ol>
		<li>Create solutions of 10% sucrose and 0.005% L-menthol in deionized water (pH 7.4). Store these solutions in closed containers, at RT, and remake every 2 weeks, to prevent degradation.</li>
	</ol>
	</li>
	<li>Electrode calibration solutions
	<ol>
		<li>Make Tris buffer (pH 7.4) at any time prior to calibration. The solution consists of 12.0 mM Tris-HCl, 140 mM NaCl, 3.25 mM KCl, 1.20 mM CaCl2, 1.25 mM NaH2PO4, 1.20 mM MgCl2, and 2.00 mM Na2SO4.</li>
		<li>Create a stock solution of 10 mM dopamine (DA; dopamine hydrochloride) in 0.1 M perchloric acid. The perchloric acid helps prevent oxidation of dopamine. Store this stock solution at -20 &#176;C and use for up to 6 months. Make several aliquots of the DA stock solution for storage to use each aliquot only once.</li>
		<li>From the 10 mM DA stock, dilute solutions in Tris buffer to concentrations of 1 &#956;M, 500 nM, 250 nM, 125 nM, 62.5 nM, and 31.25 nM.</li>
		<li>For pH calibration, prepare solutions of Tris buffer with the pH of 7.2, 7.3, 7.5, and 7.6. This will provide solutions that mimic pH shifts that may occur during the in vivo experiment.</li>
	</ol>
	</li>
	<li>Electrode fabrication
	<ol>
		<li>By vacuum suction, aspirate a T-650 carbon fiber (7 &#956;m diameter) into a borosilicate glass capillary (length 10 mm, outside diameter 0.6 mm, inside diameter 0.4 mm).</li>
		<li>Place glass capillary filled with carbon fiber into a vertical electrode puller. For initial parameters, set the heater to 55.0 and turn off the magnet. However, further optimization may be necessary as both heater and magnetic settings vary from lab to lab. 
		Note: The electrode should be at least 5.5 cm long (including taper) so that it can easily fit into the micromanipulator and be inserted at least 6.9 mm below dura in the rat brain. If the electrode is too short, recordings from ventral portion of the nucleus accumbens will not be achievable. On the other hand, the total electrode length should not exceed 6.5 cm otherwise it will be too long to fit into the micromanipulator.</li>
		<li>Using a light microscope, cut the exposed carbon-fiber so that it extends 75-100 &#956;m beyond the end of the glass. Verify that the electrode has a very tight, barely discernible, seal between the glass electrode and carbon fiber, which will produce minimal noise during subsequent recording. Discard the electrode if there are any noticeable cracks in the glass or if the seal is loose, which is indicative of a poor seal. For more detailed instructions see [12] and [13].</li>
	</ol>
	</li>
	<li>Assembling the electrode into the micromanipulator
	<ol>
		<li>Obtain a 3 in, 30G&#160;wire that is insulated along half the length of the wire and use a small brush to apply a thin layer of silver paint directly to the wire. Immediately after applying silver paint, insert the wire into the hole on the top of the electrode to provide a physical and electrical connection to the carbon fiber. Under a microscope, ensure that the silver wire makes contact with the carbon fiber.</li>
		<li>Secure the silver wire and electrode to the micromanipulator using heat shrink.</li>
		<li>Place the prepared carbon-fiber electrode into purified isopropyl alcohol (IPA) for at least 10 min to clean the electrode surface and to increase subsequent sensitivity to dopamine. After soaking in IPA, rinse the carbon fiber with tap water to remove the IPA.</li>
	</ol>
	</li>
	<li>Reference electrode fabrication
	<ol>
		<li>Take a 13 mm silver wire containing an approximately 6 mm Ag/Ag Cl mesh (7 mm silver wire alone, 6 mm mesh, 0.4 mm diameter), cut the silver portion down to approximately half its original length and solder the silver portion of the wire to a gold pin.</li>
		<li>Apply epoxy over the solder on the pin.</li>
		<li>Dip the Ag/Ag Cl mesh end into a copolymer of 5% polytetrafluroethylene and perfluoro-3,6-dioxa-4-methyl-7octene-sulfonic acid 5 times, with 30 min&#160;air drying periods between each dip.</li>
		<li>Allow the coated Ag/Ag Cl mesh to air dry O/N.</li>
		<li>Cure in oven at 120 &#186;C for 1 hr.</li>
	</ol>
	</li>
</ol>
&#160;2) Combined Intraoral Surgery and Intracranial Cannulation Surgery (Approximately 75 min)
<ol>
	<li>Oral catheter fabrication
	<ol>
		<li>Make the oral catheter, and sterilize by ethylene oxide sterilization, at least 10 days prior to surgery.</li>
		<li>Cut PE 100 tubing into 6 cm long segments.</li>
		<li>Using a soldering iron, melt one end of the PE tubing and immediately press against a solid surface to cool the PE tubing. The result should create a small, flat disc at one end of the PE tubing and should not be flanged. Use a needle (18 G) or push pin to create a hole in the center of this disc.</li>
		<li>On the other end of the PE tubing, snugly insert the blunt end of a 18 G needle into the tube.</li>
		<li>Using a standard paper hole puncher, punch several circular pieces of a polytetrafluroethylene sheet (3.18 mm thick, 6 mm in diameter) to create polytetrafluroethylene washers.</li>
		<li>Create a hole in the center of the washer. Take the needle attached to the PE tubing and push it completely through the washer. Once the needle is through, slide the washer to the bottom of the PE tubing so that it is flush against the washer.</li>
	</ol>
	</li>
	<li>Oral surgery
	<ol>
		<li>After sterilizing the surgical tools, cannula (trimmed to 2.5 mm below the pedestal before sterilization), and reference electrode, anesthetize the rat with an intraperitoneal injection of ketamine (100 mg/kg) and xylazine (10 mg/kg).
		<ol>
			<li>After 5 min, apply a noxious stimulus test (foot or tail pinch) to assess the level of anesthesia. If the subject shows any physical reaction to the noxious stimulus test (flinch response, increase in respiratory or heart rate), administer a ketamine boost of 10% to 15% of the original dose and repeat the noxious stimulus protocol above.</li>
		</ol>
		</li>
		<li>After the rat is fully anesthetized and shows no reaction to the noxious stimulus test, use animal hair clippers to shave the rat&#39;s fur from the eyes to about 2 mm behind the ears. Then place the rat on a thin water recirculating heating pad to maintain body temperature during surgery. Apply eye lubricant. Administer the non-steroidal anti-inflammatory (NSAID) drug, Carprofen (5 mg/kg), by intraperitoneal injection prior to performing any incisions and prior to inserting intraoral cannulas. Use aseptic technique at all times.</li>
		<li>Apply betadine followed by 70% ethanol to clean the skin. Repeat 3 times.</li>
		<li>Place the rat on its back, and open the mouth using a sterile cotton swab. Find the first upper molar.</li>
		<li>Insert the needle into the tissue between the cheek and the first upper molar until the needle exits just behind and medial to the ears.</li>
		<li>Pierce the needle through the skin until the PE tubing exits the skin and is accessible.</li>
		<li>Pull up on the cannula (gripping by the cannula itself and not the needle) and secure the polytetrafluroethylene washer into the molars so that the catheter remains in place. 
		Note: Cutting the washer into a trapezoid shape and securing it against the molars with the flat side facing the cheek makes this step easier.</li>
		<li>Take another polytetrafluroethylene washer and slide it over the exposed needle, down the plastic tubing, and abut against the incision.</li>
		<li>To secure the polytetrafluroethylene washer, use sterilized tape to create a triangular &#34;flag&#34; so that the washer does not slide up. Secure the washer against the rat&#39;s skin and the sterilized tape.</li>
		<li>Cut the exposed catheter to allow 2-4 cm of tubing to be exposed above the rat&#39;s head.</li>
		<li>Repeat steps 2.2.1 through 2.2.10 for the other side of the mouth.</li>
	</ol>
	</li>
	<li>Intracranial surgery for voltammetry
	<ol>
		<li>Place the rat in the stereotaxic frame and clean the animal&#8217;s scalp using a two stage scrub (a betadine scrub followed by a 70% ethanol scrub, perform with a 3 cycle repetition).</li>
		<li>Use sterilized needle nose tweezers and surgical scissors to cut away a 15 x 15 mm section of scalp tissue.</li>
		<li>Gently clean the surface of the skull using sterilized cotton tip applicators. Further clean the skull by applying 2 to 3 drops of 3% hydrogen peroxide.</li>
		<li>Use a stereotaxic drill to make 3 small (1 mm diameter) holes in the skull for subsequent insertion of screws, 1 hole for the guide cannula, 1 hole for the stimulating electrode, and 1 hole for the reference electrode.</li>
		<li>For recordings in the NAc core, position the guide cannula at 1.2 mm anterior and 1.4 mm lateral to Bregma. Lower the cannula apparatus until the plastic base is flush with the skull.</li>
		<li>Place the sterilized reference electrode in the hemisphere contralateral to the guide cannula. Lower the reference approximately 2 mm below the dura.</li>
		<li>Position the stimulating electrode at 5.2 mm posterior and 1.0 mm lateral to Bregma and lowered 8.0 mm below dura to target the ventral tegmental area (VTA).</li>
		<li>Use a sterilized small surgical screwdriver to secure screws to the skull. Then, insert the reference electrode, stimulating electrode, and guide cannula. Finally, secure all components using cranioplastic cement.</li>
		<li>For the first 48 hours of post-operative care, administer the non-steroidal anti-inflammatory drug (NSAID) Carprofen by subcutaneous injection (5 mg/kg). Allow at least 1 week for complete surgical recovery prior to performing voltammetry recording.
		<ol>
			<li>During post-operative care, flush oral catheters daily with water. Provide food saturated in water for 2 days to aid the animal in chewing and eating.&#160; Provide daily monitoring for potential signs of stress of pain (due to mild infection or dehydration) and provide appropriate interventions as necessary (including administration of fluids, topical administration of antiseptics, and or NSAID Carprofen administration at 5 mg/kg).</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>
3) Voltammetric Recordings in Awake, Freely Moving Rat
<ol>
	<li>Lowering the electrode and acquiring a DA training set.
	<ol>
		<li>On the day of the experiment, check the patency of the oral cannula by infusing 200 &#956;l of water and observing orofacial responses (to verify that the rat is tasting the water).</li>
		<li>Attach the FSCV headstage to the rat by inserting the stimulating electrode (on the headstage) into the bipolar stimulating electrode cannula (on the rat). Thus, the headstage (miniaturized current-to-voltage converter) connects directly to the bipolar stimulating electrode.</li>
		<li>Remove the dummy cannula from the cannula apparatus and apply two drops of 50% heparin solution into the cannula. Then gently insert a dummy cannula (slightly longer that the dummy cannula that was previously removed) to clear any blood clots or glial scarring that may have occurred, which will break carbon fiber electrodes that will subsequently be inserted during the experiment. Extend the cannula used for clearing clots 3-4 mm below the skull (at least 2 mm above the recording site).</li>
		<li>Insert the micromanipulator, with electrode, into the guide cannula and place the omega ring in a &#34;locked&#34; position.</li>
		<li>Connect the reference electrode wire from the headstage to the appropriate pin. Then connect the working electrode wire from the micromanipulator to the appropriate wire on the headstage.</li>
		<li>Lower the electrode to approximately 4-4.5 mm below skull.</li>
		<li>Use a potentiostat to apply a triangular waveform (400 V/s, -0.4 to +1.3 V). Apply the waveform to the electrode at 60 Hz for at least 10 min, then change the waveform application frequency to 10 Hz for subsequent experimental recordings. 
		Note: The 60 Hz waveform application step produces a stable carbon fiber surface and will help prevent electrical drift</li>
		<li>Apply electrical stimulation to the VTA using various frequencies (10 to 60 Hz) pulses (10 to 30 pulses) and currents (50 to 150 &#956;A) all with a pulse width of 2 ms/phase, to evoke different concentrations of DA release and pH shifts. Acquire at least 5 different concentrations of DA release and 5 different pH shifts. Wait (2 - 3 min&#160;minimum) between stimulations to allow for vesicular reloading[14]. 
		Note: It is important to obtain stimulations that produce DA concentrations across the entire range that will be collected during the subsequent experiment since they will be used as a training set for Principal Component Analysis (see section 5.1).</li>
		<li>Lower the electrode into the NAc core (6.3 mm ventral to dura). Subsequently lower the electrode in 100 &#956;m increments within the NAc core until transient DA release events are observed at frequencies of at least 1 per min.</li>
		<li>Connect the tubing (inner diameter 1/32&#34;, outer diameter 3/32&#34;) to a 20 ml syringe, attached to a syringe pump. On the other end of the tube, use a beveled 23 G needle to connect the tubing to the rat&#39;s cannula. Ensure that the tubing is filled completely with the desired tastant and verify that no bubbles exist in the tubing. 
		Note: Typically, administer a small amount of tastant into the mouth of the rat prior to recording to ensure that the first infusion for recording delivers the full infusion amount and not any residual water or air in the tubing. Moreover, this allows the animal to have some prior experience with the tastant since novel tastants, even appetitive ones, can be aversive initially due to its novelty.</li>
		<li>For data collection, infuse 200 &#956;l of tastant (6.5 sec using a pump and previously described tubing). Infuse the tastant every 1-3 min. Infuse a total of 25 times per tastant. Each infusion delivers 200 &#956;l of solution.</li>
		<li>If multiple tastants are being delivered in a single experiment, flush the oral catheter with water after collecting data for one tastant and wait at least 20 min&#160;before infusing the new tastant.</li>
		<li>After the DA recording session, prepare for histological verification by creating a small lesion at the recording site. To preserve the carbon fiber electrode for subsequent calibration, first retract the electrode and remove the micromanipulator. Then use a new micromanipulator with a glass microelectrode and a tungsten wire (extending 100&#160;&#956;m beyond the glass tip) to the same depth (below dura) as the original carbon fiber microelectrode.</li>
		<li>For histological verification, create a small lesion by applying 3 V at the tungsten wire and increasing the voltage at 1 V increments, every 10 sec, until the 10 V setting is reached.</li>
		<li>If a standard concentration curve has already been created using multiple carbon fiber electrodes, perform the lesion step above (3.1.14) by applying the potential directly the carbon fiber electrode. 
		Note: This lesion method will damage the carbon fiber and prevent subsequent calibration with that specific electrode.</li>
		<li>Euthanize the animal using a lethal injection pentobarbital (150 mg/kg, i.p.).</li>
		<li>Dislodge the headcap with the cannulae using pliers by pulling directly upward on the headcap. Do not twist the headcap since this will cause unnecessary damage to the brain and make it challenging to identify the location of the electrode during histology.
		<ol>
			<li>Remove the brain and place in 4% formalin for 3 days followed by 30% sucrose for 1 week. Create 30 &#956;m slices using a cryostat, mount on cover slips and examine slices under a light microscope to identify the location of the carbon fiber or tungsten lesion. 
			Note: Perfusion is optional for 3.1.17.</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>
4) Electrode Calibration
<ol>
	<li>Using the flow cell to create a current-concentration conversion factor.
	<ol>
		<li>In order to determine electrode sensitivity, calibrate electrodes after each experiment using a flow &#34;t-cell&#34; apparatus. Lower the electrode into the &#34;t-cell&#34; while Tris buffer, pH solutions, or DA solutions are washed over the electrode surface (at a rate of 2 ml/min). Use a six-position air solenoid actuator to switch back and forth between buffer and pH or DA solution.</li>
		<li>For each calibration, collect voltammetric data during 5 sec application of Tris buffer (baseline) followed by 5 sec application of pH or DA solution, followed by 20 sec application of Tris buffer (30 sec total file). Repeat each run 3 times for each calibration standard concentration, counterbalancing between different concentrations of each standard.</li>
		<li>For each sample collection, measure the peak DA or pH-evoked current. Average the peak current across each trial to obtain a concentration versus peak current relationship. For more detailed instructions see [12] and [13].</li>
	</ol>
	</li>
</ol>
5) Data Analysis
<ol>
	<li>Using a training set in principal component analysis (PCA) 
	Note: During a voltammetry experiment, output is produced as current, which is the result of dopamine oxidation and reduction, pH shifts, and electrochemical noise. PCA allows separation of these factors so that one can isolate the desired components (DA and pH) and remove additional components that might distort the desired signals (for a more detailed description, see 15, 16).
	<ol>
		<li>Assign a calibration factor to the output current (approximately 5-10 nA/&#956;M) after PCA to allow concentration values of the analytes to be determined.</li>
		<li>Use the training set obtained during an experiment to &#34;train&#34; the PCA model to separate out DA, pH, and other factors. PCA takes the training set cyclic voltammograms (collected in section 3.1.8) and determines which essential characteristics of the voltammogram can be used to identify each analyte collected during in vivo voltammetry recordings.</li>
		<li>To determine the number of principal components to keep, use a Malinowski F-test. Typically, keep only 2 or 3 principal components which normally explain about 95-99% of the variance in the data. For further discussion on implementing the Malinowski F-test, see17. 
		Note: Once the number of components are determined, the PCA analysis effectively will project the measured voltammograms from DA and pH training sets onto the principal components that have been retained. The result is a data set that has been filtered so that only DA (or pH) data remains and the residual data that does not resemble DA or pH is removed (See Representative Results for expected output). For a further detailed explanation and step by step instruction for using PCA for voltammetric analysis see Materials sheet and16, 17.</li>
	</ol>
	</li>
</ol>

<ol><li>Roitman, M. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Dopamine+operates+as+a+subsecond+modulator+of+food+seeking%5BTitle%5D)+AND+%22J+Neurosci%22%5BJournal%5D)">Dopamine operates as a subsecond modulator of food seeking.</a> J Neurosci. 24 (6), 1265-1271 (2004).</li>
<li>Aragona, B. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Regional+specificity+in+the+real-time+development+of+phasic+dopamine+transmission+patterns+during+acquisition+of+a+cue-cocaine+association+in+rats%5BTitle%5D)+AND+%22European+Journal+of+Neuroscience%22%5BJournal%5D)">Regional specificity in the real-time development of phasic dopamine transmission patterns during acquisition of a cue-cocaine association in rats.</a> European Journal of Neuroscience. 30 (10), 1889-1899 (2009).</li>
<li>Wheeler, R. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Cocaine+cues+drive+opposing+context-dependent+shifts+in+reward+processing+and+emotional+state%5BTitle%5D)+AND+%22Biol+Psychiatry%22%5BJournal%5D)">Cocaine cues drive opposing context-dependent shifts in reward processing and emotional state.</a> Biol Psychiatry. 69 (11), 1067-1074 (2011).</li>
<li>Wickham, R. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Advances+in+studying+phasic+dopamine+signaling+in+brain+reward+mechanisms%5BTitle%5D)+AND+%22Front+Biosci+%28Elite+Ed%29%22%5BJournal%5D)">Advances in studying phasic dopamine signaling in brain reward mechanisms.</a> Front Biosci (Elite Ed). 5, 982-999 (2013).</li>
<li>Roitman, M. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Real-time+chemical+responses+in+the+nucleus+accumbens+differentiate+rewarding+and+aversive+stimuli%29%5BTitle%5D)+AND+%22Nature+Neuroscience%22%5BJournal%5D)">Real-time chemical responses in the nucleus accumbens differentiate rewarding and aversive stimuli).</a> Nature Neuroscience. 11 (12), 1376-1377 (2008).</li>
<li>Cheer, J. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Phasic+dopamine+release+evoked+by+abused+substances+requires+cannabinoid+receptor+activation%5BTitle%5D)+AND+%22J+Neurosci%22%5BJournal%5D)">Phasic dopamine release evoked by abused substances requires cannabinoid receptor activation.</a> J Neurosci. 27 (4), 791-795 (2007).</li>
<li>Owesson-White, C. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Neural+encoding+of+cocaine-seeking+behavior+is+coincident+with+phasic+dopamine+release+in+the+accumbens+core+and+shell%5BTitle%5D)+AND+%22Eur+J+Neurosci%22%5BJournal%5D)">Neural encoding of cocaine-seeking behavior is coincident with phasic dopamine release in the accumbens core and shell.</a> Eur J Neurosci. 30 (6), 1117-1127 (2009).</li>
<li>Phillips, P. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Subsecond+dopamine+release+promotes+cocaine+seeking%5BTitle%5D)+AND+%22Nature%22%5BJournal%5D)">Subsecond dopamine release promotes cocaine seeking.</a> Nature. 422 (6932), 614-618 (2003).</li>
<li>Chen, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Levels+of+mint+and+wintergreen+flavorants%3A+smokeless+tobacco+products+vs.+confectionery+products%5BTitle%5D)+AND+%22Food+Chem+Toxicol%22%5BJournal%5D)">Levels of mint and wintergreen flavorants: smokeless tobacco products vs. confectionery products.</a> Food Chem Toxicol. 48 (2), 755-763 (2010).</li>
<li>Manning, K. C., Kelly, K. J., Comello, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Flavoured+cigarettes%2C+sensation+seeking+and+adolescents%27+perceptions+of+cigarette+brands%5BTitle%5D)+AND+%22Tob+Control%22%5BJournal%5D)">Flavoured cigarettes, sensation seeking and adolescents' perceptions of cigarette brands.</a> Tob Control. 18 (6), 459-465 (2009).</li>
<li>Rainey, C. L., Conder, P. A., Goodpaster, J. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Chemical+characterization+of+dissolvable+tobacco+products+promoted+to+reduce+harm%5BTitle%5D)+AND+%22J+Agric+Food+Chem%22%5BJournal%5D)">Chemical characterization of dissolvable tobacco products promoted to reduce harm.</a> J Agric Food Chem. 59 (6), 2745-2751 (2011).</li>
<li>Phillips, P. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Real-time+measurements+of+phasic+changes+in+extracellular+dopamine+concentration+in+freely+moving+rats+by+fast-scan+cyclic+voltammetry%5BTitle%5D)+AND+%22Methods+Mol+Med%22%5BJournal%5D)">Real-time measurements of phasic changes in extracellular dopamine concentration in freely moving rats by fast-scan cyclic voltammetry.</a> Methods Mol Med. 79, 443-464 (2003).</li>
<li>Robinson, D. L., Wightman, R. M. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aRobinson%2C+DL+%22Rapid+Dopamine+Release+in+Freely+Moving+Rats.+Electrochemical+Methods+for+Neuroscience%22">Rapid Dopamine Release in Freely Moving Rats. Electrochemical Methods for Neuroscience</a>. , CRC Press. Boca Raton, FL. (2007).</li>
<li>Montague, P. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Dynamic+gain+control+of+dopamine+delivery+in+freely+moving+animals%5BTitle%5D)+AND+%22J+Neurosci%22%5BJournal%5D)">Dynamic gain control of dopamine delivery in freely moving animals.</a> J Neurosci. 24 (7), 1754-1759 (2004).</li>
<li>Heien, M. L., Johnson, M. A., Wightman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Resolving+neurotransmitters+detected+by+fast-scan+cyclic+voltammetry%5BTitle%5D)+AND+%22Anal+Chem%22%5BJournal%5D)">Resolving neurotransmitters detected by fast-scan cyclic voltammetry.</a> Anal Chem. 76 (19), 5697-5704 (2004).</li>
<li>Keithley, R. B., Heien, M. L., Wightman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Multivariate+concentration+determination+using+principal+component+regression+with+residual+analysis%5BTitle%5D)+AND+%22Trends+Analyt+Chem%22%5BJournal%5D)">Multivariate concentration determination using principal component regression with residual analysis.</a> Trends Analyt Chem. 28 (9), 1127-1136 (2009).</li>
<li>Keithley, R. B., Carelli, R. M., Wightman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Rank+estimation+and+the+multivariate+analysis+of+in+vivo+fast-scan+cyclic+voltammetric+data%5BTitle%5D)+AND+%22Anal+Chem%22%5BJournal%5D)">Rank estimation and the multivariate analysis of in vivo fast-scan cyclic voltammetric data.</a> Anal Chem. 82 (13), 5541-5551 (2010).</li>
<li>Rising, J. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Healthy+Young+Adults%3A+description+and+use+of+an+innovative+health+insurance+program%5BTitle%5D)+AND+%22J+Adolesc+Health%22%5BJournal%5D)">Healthy Young Adults: description and use of an innovative health insurance program.</a> J Adolesc Health. 41 (4), 350-356 (2007).</li>
<li>Day, J. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Associative+learning+mediates+dynamic+shifts+in+dopamine+signaling+in+the+nucleus+accumbens%5BTitle%5D)+AND+%22Nature+Neuroscience%22%5BJournal%5D)">Associative learning mediates dynamic shifts in dopamine signaling in the nucleus accumbens.</a> Nature Neuroscience. 10 (8), 1020-1028 (2007).</li>
<li>Park, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Catecholamines+in+the+bed+nucleus+of+the+stria+terminalis+reciprocally+respond+to+reward+and+aversion%5BTitle%5D)+AND+%22Biol+Psychiatry%22%5BJournal%5D)">Catecholamines in the bed nucleus of the stria terminalis reciprocally respond to reward and aversion.</a> Biol Psychiatry. 71 (4), 327-334 (2012).</li>
<li>Wheeler, R. A., Carelli, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+neuroscience+of+pleasure.+Focus+on+%27Ventral+pallidum+firing+codes+hedonic+reward%3A+when+a+bad+taste+turns+good%5BTitle%5D)+AND+%22J+Neurophysiol%22%5BJournal%5D)">The neuroscience of pleasure. Focus on 'Ventral pallidum firing codes hedonic reward: when a bad taste turns good.</a> J Neurophysiol. 96 (5), 2175-2176 (2006).</li>
<li>Bunin, M. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Release+and+uptake+rates+of+5-hydroxytryptamine+in+the+dorsal+raphe+and+substantia+nigra+reticulata+of+the+rat+brain%5BTitle%5D)+AND+%22J+Neurochem%22%5BJournal%5D)">Release and uptake rates of 5-hydroxytryptamine in the dorsal raphe and substantia nigra reticulata of the rat brain.</a> J Neurochem. 70 (3), 1077-1087 (1998).</li>
<li>Zimmerman, J. B., Wightman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Simultaneous+electrochemical+measurements+of+oxygen+and+dopamine+in+vivo%5BTitle%5D)+AND+%22Anal+Chem%22%5BJournal%5D)">Simultaneous electrochemical measurements of oxygen and dopamine in vivo.</a> Anal Chem. 63 (1), 24-28 (1991).</li>
<li>Levy, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+novel+procedure+for+evaluating+the+reinforcing+properties+of+tastants+in+laboratory+rats%3A+operant+intraoral+self-administration%5BTitle%5D)+AND+%22J+Vis+Exp%22%5BJournal%5D)">A novel procedure for evaluating the reinforcing properties of tastants in laboratory rats: operant intraoral self-administration.</a> J Vis Exp. (84), e50956(2014).</li>
</ol>

The authors have nothing to disclose.

Intraoral tastant delivery combined with FSCV permits analysis of &#8220;real-time&#8221; DA responses to oral flavorants. There are three critical steps in the protocol that are required for successful DA measurements. First, proper implantation of the oral catheter is critical for delivery of flavorants. Ensuring that the catheter is inserted behind the first molar and wedged into place prevents the catheter from losing patency and prevents accidental removal by the animal. Flushing the catheter during the first few da...

Erratum: Examination of Rapid Dopamine Dynamics with Fast Scan Cyclic Voltammetry During Intra-oral Tastant Administration in Awake Rats

Phasic DA release plays an important role in mediating reward-directed behavior [1-3]. However, isolating and studying how a primary reward alters phasic DA release is often complicated by co-occurring behavioral or cognitive processes that are also capable of altering phasic DA release - such as decision making processes or reward-directed motor behavior to acquire the reward. In the current work, we isolate phasic DA responses to tastants through the use of in vivo fast-scan cyclic voltammetry (FSCV) combined with tastant delivery through intraoral cannulae. This technique bypasses choice and action and allows us to examine extracellular DA release during direct infusion of a tastant to the palate of a rat.
FSCV is an electrochemical technique with high temporal and spatial resolution, permitting measurements of DA release in a discrete local area (approximately 100 &#181;m) on a sub-second scale (10 Hz resolution). The combination of intra-oral delivery and FSCV provides the advantage of observing rapid, 'real-time' DA responses to a tastant, which cannot be examined using conventional microdialysis methods. Furthermore, phasic DA release in response to either rewards or reward-associated cues occurs at concentrations between 20-100 nM, which is above the 10-20 nM detection threshold for FSCV [4]. The high spatial resolution of FSCV also permits recording from sub-regions of small brain areas, such as the nucleus accumbens core (NAc). Thus, FSCV combined with intraoral infusions of tastants is an ideal model for studying how tastants or other stimuli alter phasic DA release in an awake, behaving animals. Indeed, these techniques have permitted experiments investigating how rewarding and aversive tastants alter extracellular DA release [5]. 
Over the last decade, FSCV analyses have been successfully combined with intravenous drug delivery [6] and rat self-administration paradigms [7, 8] to identify the role of phasic DA mechanisms in drug addiction models. In addition, combined intraoral delivery with FSCV has been used to examine how tastant cues paired with cocaine availability modulate phasic DA release and behavioral responses that reflect emotional affect [3]. This combined intraoral and FSCV methodology can also be powerfully utilized to examine phasic DA responses to flavorants, such as menthol and oral sweeteners, that are added to cigarettes and dissolvable tobacco products [9-11]. Although many of the flavorants added to tobacco products are appetitive [9-11], it is unknown if these flavorants increase phasic DA release in a manner consistent with a rewarding hedonic valence. Indeed, flavorants added to cigarettes and to dissolvable tobacco products may have direct effects on the DA reward system and may act through dopaminergic mechanisms to influence the rewarding valence of cigarettes and other tobacco products. Thus, intraoral delivery combined with FSCV can provide new understanding on how flavorants modulate rapid DA release. The use of combined intra-oral and in vivo FSCV methodology, and the data obtained from such studies, can also facilitate future studies to determine how flavorants and nicotine interact to alter DA signaling and to potentially modulate nicotine reinforcement. Further, the data gained from such studies can be used to inform regulatory decisions about tobacco product flavorants.

<table><tbody><tr><td>Stimulating electrode</td><td>PlasticsOne</td><td>MS303/2-A/SPC</td><td>when ordering, request a 22 mm cut below pedestal</td></tr><tr><td>Cannula for electrode</td><td>BioAnalytical Systems</td><td>MD-2251</td><td></td></tr><tr><td>Glass capillary</td><td>A-M systems</td><td>624503</td><td></td></tr><tr><td>Carbon fiber</td><td>Thornel</td><td>T650</td><td></td></tr><tr><td>Electrode puller</td><td>Narishige International</td><td>PE-22</td><td></td></tr><tr><td>&lt;a href="http://digitimer.com/products/neurolog-system/" target="_blank"&gt;Neurolog stimulus isolator&lt;/a&gt;</td><td><a href="http://www.digitimer.com" target="_blank"><img src="/img/new_window.png"> &lt;a href="http://digitimer.com" target="_blank"&gt;Digitimer Ltd.&lt;/a&gt;</a></td><td>&lt;a href="http://digitimer.com/products/research/stimulators/ds4-bi-phasic-stimulus-isolator/" target="_blank"&gt;DS4&lt;/a&gt;</td><td></td></tr><tr><td>Heat shrink</td><td>3M</td><td>FP-301</td><td></td></tr><tr><td>Insulated wires for electrodes</td><td>Squires electronics</td><td>Custom</td><td>L 3.000 x 1.000s x 1.000s UL1423 30/1 BLU</td></tr><tr><td>Micromanipulator</td><td>Univ. of Illinois at Chicago, Engineering Machine Shop</td><td></td><td></td></tr><tr><td>Epoxy</td><td>ITW Devcon</td><td>14250</td><td>"5 minute epoxy"</td></tr><tr><td>Copolymer of perfluoro-3,6-dioxa-4-methyl-7octene-sulfonic acid and tetrafluoroethylene</td><td>Ion Power</td><td>LQ-1105</td><td>&lt;em&gt;i.e.,&lt;/em&gt; Nafion</td></tr><tr><td>Silver paint</td><td>GC Electronics</td><td>22-023</td><td></td></tr><tr><td>Power supply</td><td>BK Precision</td><td>9110</td><td></td></tr><tr><td>Tubing for intra-oral catheters</td><td>Intramedic</td><td>427426</td><td>PE 100, I.D. = 0.86 mm; O.D. = 1.52 mm</td></tr><tr><td>Tubing for intra-oral infusion</td><td>Fischer Scientific</td><td>02-587-1A</td><td>I.D. 1/32"; O.D. 3/32"</td></tr><tr><td>Syringe pump for flow cell</td><td>Pump Systems Inc.</td><td>NE 1000</td><td></td></tr><tr><td>Surgical cement</td><td>Dentsply Caulk</td><td>675571 and 675572</td><td></td></tr><tr><td>Air actuator</td><td>VICI</td><td>A60</td><td>6 position digital valve interface</td></tr><tr><td>Digital valve interface</td><td>VICI</td><td>DVI</td><td>230 VAC</td></tr><tr><td>Quad headstage</td><td>Univ. of N. Carolina, Electronics Facility</td><td></td><td></td></tr><tr><td>UEI power supply</td><td>Univ. of N. Carolina, Electronics Facility</td><td></td><td></td></tr><tr><td>UEI breakout box</td><td>Univ. of N. Carolina, Electronics Facility</td><td></td><td></td></tr><tr><td>Power supply for tastant syringe pump</td><td>Med Associates</td><td>SG-504</td><td></td></tr><tr><td>Tastant syringe pump</td><td>Med Associates</td><td>PHM-107</td><td></td></tr><tr><td>Tungsten microelectrode</td><td>MicroProbes</td><td>WE30030.5A3</td><td></td></tr><tr><td>Silver wire reference with AgCl</td><td>InVivo Metric</td><td>E255A</td><td></td></tr><tr><td>Sucrose</td><td>Sigma</td><td>80497</td><td></td></tr><tr><td>Magnesium chloride</td><td>Sigma</td><td>M8266</td><td></td></tr><tr><td>Sodium chlroide</td><td>Sigma</td><td>S7653</td><td></td></tr><tr><td>Perchloric acid</td><td>Sigma</td><td>244252</td><td></td></tr><tr><td>Hydrochloric acid (4 M)</td><td>Sigma</td><td>54435</td><td></td></tr><tr><td>Soidum hydroxide</td><td>Sigma</td><td>306576</td><td></td></tr><tr><td>Hydrogen peroxide</td><td>Sigma</td><td>H1009</td><td></td></tr><tr><td>Dopamine hydrochloride</td><td>Sigma</td><td>H8502</td><td></td></tr><tr><td>TarHeel HDCV Software</td><td>University of North Carolina-Chapel Hill</td><td></td><td>&lt;a href="http://www.chem.unc.edu/facilities/index.html?display=electronics&amp;amp;content=software&amp;amp;software_id=2" target="_blank"&gt;Must request software: click here for link to software request page&lt;/a&gt;</td></tr></tbody></table>

examination of rapid dopamine dynamics with fast scan cyclic voltammetry during intra-oral tastant administration in awake rats

Examination of Rapid Dopamine Dynamics with Fast Scan Cyclic Voltammetry During Intra-oral Tastant Administration in Awake Rats

Rapid, phasic dopamine (DA) release in the mammalian brain plays a critical role in reward processing, reinforcement learning, and motivational control. Fast scan cyclic voltammetry (FSCV) is an electrochemical technique with high spatial and temporal (sub-second) resolution that has been utilized to examine phasic DA release in several types of preparations. In vitro experiments in single-cells and brain slices and in vivo experiments in anesthetized rodents have been used to identify mechanisms that mediate dopamine release and uptake under normal conditions and in disease models. Over the last 20 years, in vivo FSCV experiments in awake, freely moving rodents have also provided insight of dopaminergic mechanisms in reward processing and reward learning. One major advantage of the awake, freely moving preparation is the ability to examine rapid DA fluctuations that are time-locked to specific behavioral events or to reward or cue presentation. However, one limitation of combined behavior and voltammetry experiments is the difficulty of dissociating DA effects that are specific to primary rewarding or aversive stimuli from co-occurring DA fluctuations that mediate reward-directed or other motor behaviors. Here, we describe a combined method using in vivo FSCV and intra-oral infusion in an awake rat to directly investigate DA responses to oral tastants. In these experiments, oral tastants are infused directly to the palate of the rat &#8211; bypassing reward-directed behavior and voluntary drinking behavior &#8211; allowing for direct examination of DA responses to tastant stimuli.

FSCV combined with intraoral catheter implantation was used to examine how sucrose, an appetitive tastant, modulates phasic DA release in the NAc core. Prior to tastant infusion, electrical stimulation (150 µA, 60 Hz, 24 pulses; indicated by the red bar) of the VTA produces robust increases in phasic DA release in the NAc (Figure 1). Figure 1 shows a color plot with potential on the y-axis, time on the x-axis, and current (represented as false color) on the z-axis. Below the color plot i...

Rapid fluctuations in extracellular dopamine (DA) mediate both reward processing and motivated behavior in mammals. This manuscript describes the combined use of fast scan cyclic voltammetry (FSCV) and intra-oral tastant administration to determine how tastants alter rapid dopamine release in awake, freely moving rats.

Rapid, phasic dopamine (DA) release in the mammalian brain plays a critical role in reward processing, reinforcement learning, and motivational control. ...

The overall goal of this procedure is to measure subsecond dopamine responses to oral taste dense. This is accomplished by first creating oral catheters, reference electrodes and carbon fiber electrodes needed for the surgical procedures and subsequent recording via fast scan cyclic V telemetry. The second step is to surgically implant the oral catheters, the intracranial electrode, and the guide cannula for the carbon fiber electrode.One week later, the carbon fiber micro electrode can be lowered into the nucleus accumbens to record changes of extracellular dopamine release in response to intraoral delivery of tastes. The final step after recording is to calibrate the electrode and to use principle component analysis to isolate data that contains information about dopamine. Ultimately, the combined use of intraoral taste and delivery and fast scan cyclic vol telemetry is used to show changes in sub-second dopamine responses to taten.There are two main advantages of this combined technique over existing methods. First, fast IC Photometry has a high temporal resolution and second intraoral delivery of taten minimizes the movement the rat needs to make to obtain the tatin and allows us to better isolate dopamine responses to the tatin. Generally, individuals new to this method will struggle with fabrication of the oral catheter.However, constructing a good and paid oral catheter will ensure a snug fit of the catheter between the cheek and the upper molars, and increase the likelihood of a successful experiment. To prepare the recording electrode first aspirate a seven micron diameter T six 50 carbon fiber into a bora silicate glass capillary with an inner diameter of 0.4 millimeters. Next, position the capillary in a vertical electrode polar initially pull with a heater set to 55.0 and the magnet off, then adjust as needed.After pulling the pipette under a microscope, cut the exposed carbon fiber so it extends 75 to 100 microns beyond the glass. The fiber in the glass must be tightly sealed, otherwise discard the preparation. Next, strip the insulation from half of a three inch 30 gauge wire, apply heat shrink to secure the electrode to the micro manipulator.Then apply a thin layer of silver paint to the wire while the paint is still wet. Insert the wire into the open end of the electrode and attach it to the carbon fiber therein. Verify this contact under a microscope.Take the electrode in the micro manipulator and secure it with heat shrink. Place the prepared carbon fiber electrode into IPA for at least 10 minutes to clean the electrode surface and to increase subsequent sensitivity to dopamine. After removing the electrode from IPA, rinse the carbon fiber with tap water to remove the IPA.Next, prepare the reference electrode from a 13 millimeter silver wire with a six millimeter silver, silver chloride mesh with a 0.4 millimeter diameter, cut off the non meshed portion of the wire and solder it to a gold pin. Then apply epoxy to the solder. Then dip the mesh portion into a copolymer acid five times.Let it dry for 30 minutes in air between dips after the last dip. Let it air dry overnight. The next day.Bake the mesh portion of the wire at 120 degrees Celsius for an hour. To make the oral catheter first cut. Polyethylene 100 tubing into six centimeter segments.Then make a small flat disc at one of the tube segments by melting the end and pressing it onto a flat cool surface at the center of the disc. Use an 18 gauge needle to create a hole. Attach the other end of the tube segment to the blunt end of an 18 gauge needle.Then using a hole puncher makes several six millimeter diameter, 3.18 millimeter thick pieces of polytetrafluoroethylene. Then at the center of these discs, create a hole, thus making the discs into washers. Cut the washer into a trapezoid shape to help lodge them in during molar implantation.To complete the catheter, push a needle attached to PE tubing completely through the washer, and slide the washer flush to the tubing. The following protocol takes about 75 minutes to complete. Begin with a rat prepared for surgery and open its mouth using a cotton swab.Then push the needle on a cannula into the tissue between the cheek and first upper molar so the needle exits just behind and medial to the ears. Then move up the cannula and secure the washer to the molars to steady the catheter onto the exposed needle. Slide on a washer and bring it tight to the incision.Secure this washer into position. Trim the tubing so two to four centimeters remain exposed above the rat's head. Then using the same technique, put a catheter into the other side of the mouth.Following this, put the rat into a stereotaxic frame and drill three holes for the cannulas and electrodes to make recordings in the nucleus accumbens core position. The guide cannula 1.2 millimeters anterior and 1.4 millimeters. Lateral torema.Lower the cannula apparatus until the plastic base is flushed with the skull. Put the reference electrode in the hemisphere contralateral to the guide cannula. Lower the reference about two millimeters below the dura.Then position the stimulating electrode, 5.2 millimeters posterior and 1.0 millimeters lateral torema. To target the ventral tegmental area. Lower the stimulating electrode 8.0 millimeters below dura.Then secure the components with screws and cement and provide postoperative care. Before conducting an experiment, always verify the patency of the oral cannula by infusing 200 microliters of water and watch if the rat tastes the water clear the recording site by removing the dummy cannula, adding two drops of 50%heparin to it and then gently repositioning it. The dummy must not be within two millimeters of the recording site.Now attach and stabilize the head stage to the stimulator implanted in the VTA and then lower the recording electrode into the nucleus accumbens core. Now following the text protocol, produce a training dataset. Always wait at least two minutes, but up to four to five minutes between stimulations to allow for vesicular reloading And must.Most critical step in the experiment is obtaining a high quality electrode. If the background is a characteristic rounded shape on the rising phase is a good electrode. If the rounded shape is small or closely matches the applied waveform, then try a different electrode.If the background is right where shifted, apply an offset shift to the applied waveform in a positive direction in 0.1 volt increments. Once a training set is generated at the recording site, collect data while infusing 200 microliter boluses of taten every one to three minutes for 25 infusions. Then wait at least 30 minutes and infuse the next taste in the same manner.FSCV combined with intraoral catheter implantation was used to examine how sucrose an up AIT of taten modulates phasic dopamine release in the nucleus accumbens core prior to taten infusion electrical stimulation indicated by the red bar of the VTA produced robust increases in phasic dopamine release in the nucleus accumbens core after the training set was acquired 6.5 second infusions of 200 microliters of sucrose indicated by the red bar produced in elevation in current indicated by the white arrow. This occurred at the oxidation potential of dopamine, which is indicated by the white dash line, transforming the data into a concentration versus time plot. After PCA verified that the increased current in response to the taste is the result of an increase in dopamine concentration.Another tatin menthol was infused during FSCV recordings in the nucleus accumbens core increased dopamine concentration was also observed after infusion of menthol Once mastered, the combined intraoral and cannulation surgery can be performed in 75 minutes. This technique can be combined with other forms of behavior such as a competitive and aversive Pavlovian and opera conditioning in order to answer questions about subsecond dopamine signaling during these processes.

examination-rapid-dopamine-dynamics-with-fast-scan-cyclic-voltammetry

Research

JoVE Journal

Behavior

Using fast-scan cyclic voltammetry to measure electrically evoked presynaptic dopamine dynamics in striatal brain slices.

Presynaptic Dopamine Dynamics in Striatal Brain Slices with Fast-scan Cyclic Voltammetry

This video demonstrates the implantation of electrodes and cannulas in an anesthetized rat to measure dopamine release in the nucleus accumbens using a potentiostat and the infusion of drugs to modulate dopaminergic activity in the ventral tegmental area.

Monitoring Dopamine Release in a Rat Model with VTA Dopaminergic Neuron Receptor Manipulation

The current study evaluates a novel procedure for assessing the reinforcing effects of palatable solutions in laboratory rats: intraoral self-administration. To this end, operant responding (i.e. lever pressing) for intraoral infusions of sweet solutions at different concentrations was measured on continuous and progressive ratios schedules of reinforcement.

A Novel Procedure for Evaluating the Reinforcing Properties of Tastants in Laboratory Rats: Operant Intraoral Self-administration

The goal of this study is to identify reward-related distributed brain networks by delineating a reliable immunohistological technique using cellular c-fos activation to measure simultaneous changes in dopamine pathways and terminal sites after novel ingestion of fat and sugar in rats.

Simultaneous Detection of c-Fos Activation from Mesolimbic and Mesocortical Dopamine Reward Sites Following Naive Sugar and Fat Ingestion in Rats

Fast-scan cyclic voltammetry can monitor in vivo dopamine neurotransmission in the context of drugs, disease, and other experimental manipulations. This work describes the implementation of QNsim1.0, a software to model electrically stimulated dopamine responses according to the quantitative neurobiological model to quantify estimates of dopamine release and reuptake dynamics.

Modeling Fast-scan Cyclic Voltammetry Data from Electrically Stimulated Dopamine Neurotransmission Data Using QNsim1.0

Synaptosomal dopamine uptake and high-performance liquid chromatography analysis represent experimental tools to investigate dopamine homeostasis in mice by assessing the function of the dopamine transporter and levels of dopamine in striatal tissue, respectively. Here we present protocols to measure dopamine tissue content and assess the functionality of the dopamine transporter.

Assessment of Dopaminergic Homeostasis in Mice by Use of High-performance Liquid Chromatography Analysis and Synaptosomal Dopamine Uptake

This paper details the use of fixed-potential amperometric recordings using carbon fiber electrodes and enzymatic biosensor technology to measure the release of dopamine and glutamate with high temporal resolution during natural rewarding behavior in the female hamster.

Measuring In Vivo Changes in Extracellular Neurotransmitters During Naturally Rewarding Behaviors in Female Syrian Hamsters

The goal of this protocol is to directly manipulate ventral tegmental area receptors to study their contribution to subsecond dopamine release.

Combined Infusion and Stimulation with Fast-Scan Cyclic Voltammetry (CIS-FSCV) to Assess Ventral Tegmental Area Receptor Regulation of Phasic Dopamine

We present a novel PET imaging approach for capturing dopamine fluctuations induced by cigarette smoking.  Subjects smoke in the PET scanner. Dynamic PET images are modeled voxel-by-voxel in time by lp-ntPET, which includes a time-varying dopamine term. The results are 'movies' of dopamine fluctuations in the striatum during smoking.

Creating Dynamic Images of Short-lived Dopamine Fluctuations with lp-ntPET:  Dopamine Movies of Cigarette Smoking

The design and assembly of microdrives for in vivo electrophysiological recordings of brain signals from the mouse is described. By attaching microelectrode bundles to sturdy driveable carriers, these techniques allow for long-term and stable neural recordings. The lightweight design allows for unrestricted behavioral performance by the animal following drive implantation.

Construction of Microdrive Arrays for Chronic Neural Recordings in Awake Behaving Mice

Learn fast scan cyclic voltammetry for measuring rapid dopamine dynamics in awake rats during intra-oral tastant administration. This method enables precise neurotransmitter detection in reward processing studies.

Examination of Rapid Dopamine Dynamics with Fast Scan Cyclic Voltammetry During Intra-oral Tastant Administration in Awake Rats

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