Recording Changes in Renal Sympathetic Nerve Activity in Response to Arterial Pressure in Rats

Abstract

Source: Fink, A. M., et al. Quantifying Acute Changes in Renal Sympathetic Nerve Activity in Response to Central Nervous System Manipulations in Anesthetized Rats. J. Vis. Exp. (2018).

This video demonstrates a technique of studying the activity of renal sympathetic nerves (RSNs) in response to changes in arterial pressure in rats. Upon attaching a pressure-sensing catheter to the femoral artery, the renal sympathetic nerves are exposed. The nerves are then lifted onto a recording electrode, and their electrical activity is recorded. Next, a vasoconstricting drug is injected to elevate blood pressure, and corresponding changes in RSN activity are monitored.

Protocol

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

1. Create Bipolar RSNA Electrodes

1. To create the electrode, cut two pieces of stainless steel wire each approximately 18 mm long. Cut one piece of polyethylene (PE-50) tubing approximately 15 mm long. Feed both pieces of wire into the tubing, leaving the wire protruding from both ends.
2. Remove the insulation from the ends of the wires; trim the wires leaving 2-3 mm of exposed wire. On one end, crimp male pins over the exposed wire. Solder the pins securely to t....

Results

Figure 1: RSNA and BP in response to phenylephrine injection IV. The raw RSNA (A) was full-wave rectified (B); rectified crushed "zero" RSNA is shown in inset C. Non-overlapping 10 s averages (minus n.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Stainless steel wire	A-M Systems; Sequim, WA	791000	RSNA electrode
Polyethylene (PE-50) tubing	VWR; Radnor, PA	63019-048	RSNA electrode; vessel cannulation
Miniature pin connector	A-M Systems; Sequim, WA	520200	RSNA electrode
Crimping tool	Daniels Manufacturing Corp.; Orlando, FL	M22520	RSNA electrode
Connector strip	Amphenol; Clinton Township, MI	221-2653	RSNA electrode
J-B Kwik Epoxy	J-B Weld, Sulphur Springs, TX	8270	RSNA electrode
Silicone	Permatex; Hartford, CT	2222	RSNA electrode
Heparin sodium; Injectable (10 mL vial, 1000 U/mL)	KV Veterinary Supply; David City, NE	P03466	Venous line patency
Phenylephrine HCl; Injectable (1 mL vial; 10 mg/mL)	ACE Surgical Supply; Brockton, MA	950-6312	Testing renal sympathoinhibition
Single-hook elastic surgical stays	Harvard Apparatus; Holliston, MA	72-2595	Incision
Silk surgical tape	3M, Minneapolis, MN	1538-0	Secure surgical stays
Needles, 20 G	Sigma-Aldrich; St. Louis, MO	Z192554-100EA	Vessel cannulation
Dumont #7 curved forceps	Fine Science Tools; Foster City, CA	11274-20	Vessel cannulation
5-0 silk suture ties	Braintree Scientific; Braintree, MA	SUT-S 106	Vessel cannulation
Delicate hemostatic forceps	Roboz Surgical Instrument Co.; Gaithersburg, MD	RS-7117	Vessel cannulation and RSNA surgery
Crile Hemostatic forceps	Fine Science Tools; Foster City, CA	13004-14	Needle bending
Telemetry transmitter	Data Sciences International; Minneapolis, MN	PA-10	Mean arterial pressure monitoring (telemetry)
Re-gel syringe	Data Sciences International; Minneapolis, MN	276-0038-001	Transmitter reuse (telemetry)
Disposable pressure transducer	Transpac; San Clemente, CA	MI-1224	Mean arterial pressure monitoring
Clear-Cuff pressure infuser	MILA International Inc.; Florence, KY	2281339	Mean arterial pressure monitoring
Vessel cannulation forceps	Fine Science Tools; Foster City, CA	00574-11	Catheter insertion
Black monofilament nylon 4-0 suture on reverse cutting needle	McKesson Medical-Surgical; San Francisco, CA	S661GX	Secure telemetry transmitter
Telemetry receiver	Data Sciences International; Minneapolis, MN	RPC-1	Mean arterial pressure monitoring (telemetry)
LabChart Pro (software), PowerLab (acquisition hardware)	AD Instruments; Colorado Springs, CO	ML846, MX2 matrix 2.0 (Compatible with Data Science International telemetry)	3 options for software/acquisition hardware
SciWorks (software), DataWave (acquisition hardware)	DataWave Technologies, Loveland, CO	N/A
Spike 2 (software), Micro1401-3	Cambridge Electronic Design Ltd., London UK	1401-3
Micro-drill	Roboz Surgical Instrument Co.; Gaithersburg, MD	RS-6300	CNS surgery
Stereotaxic surgery frame	Stoelting; Wood Dale, IL	51600	CNS surgery
Microelectrode amplifier with 10X pre-amplifier	A-M Systems; Sequim, WA	1800-2	RSNA recording
Retractors	Fine Science Tools; Foster City, CA	17009-07	RSNA recording
Micro-dissecting tweezers	Fine Science Tools; Foster City, CA	11251-10	RSNA recording
Micro-hook	Fine Science Tools; Foster City, CA	10064-14	RSNA recording
Mineral oil	Fisher Scientific; Waltham, MA	8042-47-5	RSNA recording
Audio monitor	A-M Systems; Sequim, WA	3300	RSNA recording
Silica gel	Wacker, Munchen; Germany	RT601A-B	RSNA recording
Electrical clips	Tyco Electronics; Schaffhausen, Switzerland	EB0283-000	Grounding or securing perfusion needle
Bonn scissors, straight/sharp points	Roboz Surgical Instrument Co; Gaithersburg, MD	RS-5840	Perfusion
Gavage needle	Harvard Apparatus; Holliston, MA	75-0286	Perfusion
Masterflex perfusion pump	Cole-Parmer; Vernon Hills, IL	7524-10	Perfusion
Masterflex platinum-cured silicone tubing	Cole-Parmer; Vernon Hills, IL	96410-15	Perfusion
Formalin (10% buffered solution; 4 L)	Sigma-Aldrich; St. Louis, MO	HT501128	Perfusion
Sucrose	Sigma-Aldrich; St. Louis, MO	S0389	Cryoprotection