Optogenetic Induction of Long-Term Depression for Suppressing Narcotic-Seeking Behavior in Rats

Abstract

Source: Rich, M. T., et al. Using Optogenetics to Reverse Neuroplasticity and Inhibit Cocaine Seeking in Rats. J. Vis. Exp. (2021)

This video demonstrates the use of optogenetics to induce long-term depression (LTD) at medial geniculate nucleus to lateral amygdala (MGN-LA) synapses, weakening cue-induced narcotic-seeking behavior in a rat model. The rat, surgically implanted with optical fibers and virally transduced to express light-sensitive ion channels, undergoes optogenetic stimulation with low-frequency optical pulses, triggering neurotransmitter release and synaptic weakening. This process reduces MGN-LA synaptic transmission through neurotransmitter receptor internalization, ultimately disrupting the association between cues and drug-seeking behavior.

Protocol

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.

1. Rodent Intravenous Catheterization, Virus Delivery, and Optic Fiber Implantation

1. Prepare animals for surgery.
   1. Fully anesthetize rats with the anesthetic of choice based on institutional guidelines. One option is ketamine hydrochloride (87.5-100 mg/kg, intramuscular [i.m.]) and xylazine hydrochloride (5 mg/kg, i.m.). Ensure that the rat is fully anesthetized by checking for the lack of a toe pinch reflex.
      CAUTION: Ketamine is a controlled substance t....

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
0.9% Saline	Fisher Scientific	NC0291799
A.M.P.I. Stimulus Isolator	Iso-Flex
AAV5.hSyn.oChIEF.tdTomato	Duke Viral Vector Core (via Roger Tsien)	#268
AAV5.hSyn.tdTomato (Control)	Duke Viral Vector Core Control
Artificial Tears (Opthalmic Ointment)	Covetrus	70349
Betadine	Butler Schein	38250
Cocaine HCl	NIDA Drug Supply Center	9041-001
Dual-Channel Temperature Controller	Warner Instruments	TC-344C
Ethanol	University of Pittsburgh Chemistry Stockroom	200C5000
Ferrule Dust Caps	Thor Labs	CAPL	White plastic dust caps for 1.25 mm Ferrules
Ferrule Mating Sleeves	Doric Lenses	F210-3011	Sleeve_BR_1.25, Bronze, 1.25 mm ID
Ferrules	Precision Fiber Products	MM-FER2007C-2300	Ø1.25 mm Multimode LC/PC Ceramic ferrule, Ø230 μm hole size
Fiber Optic	Thor Labs	FP200URT	200 μm core multimode fiber (0.5 NA)
Fiber Optic Rotary Joint	Prizmatix	(Ordered from Amazon)	18 mm diameter, FC-FC connector for fiber
Fiber Stripping Tool	Thor Labs	T12S21
Gentamicin	Henry Schein	6913
Hamilton syringe	Hamilton	80085	10 μL volume, 26 gauge, 2 inch, point style 3
Heat Gun	Allied Electronics	972-6966	250 V, 750-800 °F
Heat-Curable Epoxy	Precision Fiber Products	PFP-353ND-8OZ
Heparin	Henry Schein	55737
Hydrochloric Acid	Fisher Scientific	219405490
Ketamine HCl	Henry Schein	55853	Ketamine is a controlled substance and should be handled according to institutional guidelines
Lactated Ringer’s	Henry Schein	9846
Laser, driver, and laser-to-fiber coupler	OEM Laser Systems	BL-473-00100-CWM-SD-xx-LED-0	100 mW, 473-nm, diode-pumped solid-state laser (One option)
Lidocaine	Butler Schein	14583
Light Sensor	Thor Labs	PM100D	Compact energy meter console with digital display
Loctite instant adhesive	Grainger	5.00E+207
Microelectrode Amplifier/Data Acquisition	Molecular Devices	MULTICLAMP700B / Digidata 1440A
Microinjector pump	Harvard Apparatus	70-4501	Dual syringe
Micromanipulator	Sutter Instruments	MPC-200/ROE-200
Orthojet dental cement, liquid	Lang Dental	1504BLK	black
Orthojet dental cement, powder	Lang Dental	1530BLK	Contemporary powder, black
Patch Cables	Thor Labs	FP200ERT	Multimode, FT030 Tubing
Rimadyl (Carprofen)	Henry Schein	24751
Self-Administration Chambers/Software	Med Associates	MED-NP5L-D1
Stainless steel machine screws	WW Grainger	6GB25	M2-0.40mm Machine Screw, Pan, Phillips, A2 Stainless Steel, Plain, 3 mm Length
Stereotaxic adapter for ferrules	Thor Labs	XCL
Stereotaxic Frame	Stoelting	51603
Suture Thread	Fine Science Tools	18020-50	Silk thread; Size: 5/0, Diameter: 0.12 mm
Vetbond Tissue Adhesive	Covetrus	1505