Quantifying Acute Changes in Renal Sympathetic Nerve Activity in Response to Central Nervous System Manipulations in Anesthetized Rats

Anne M. Fink; Caron Dean

doi:10.3791/58205

Quantifying Acute Changes in Renal Sympathetic Nerve Activity in Response to Central Nervous Syst...

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Neuroscience

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Quantifying Acute Changes in Renal Sympathetic Nerve Activity in Response to Central Nervous System Manipulations in Anesthetized Rats

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06:30 min

September 11, 2018

DOI: 10.3791/58205-v

Anne M. Fink¹, Caron Dean²

¹Department of Biobehavioral Health Science, College of Nursing,University of Illinois at Chicago, ²Department of Anesthesiology,Medical College of Wisconsin and Zablocki VA Medical Center

Overview

This study presents a method for measuring renal sympathetic nerve activity (RSNA) in anesthetized rats to investigate the autonomic nervous system. By examining changes in sympathetic outflow related to central nervous system manipulations, the protocol provides insights into the mechanisms regulating autonomic responses affecting kidney function.

Key Study Components

Area of Science

Neuroscience
Cardiovascular Physiology
Autonomic Regulation

Background

Understanding sympathetic outflow from the central nervous system is crucial for studying blood pressure regulation.
Techniques for assessing renal sympathetic nerve activity are essential in neuroscience research.
Manipulating the CNS can reveal important information about sympathetic regulation.
The method allows for acute assessments in vivo in a controlled environment.

Purpose of Study

To develop a protocol for measuring RSNA to central nervous system changes.
To understand the relationship between CNS manipulations and sympathetic nerve activity directed at the kidneys.
To facilitate future studies on blood pressure and renal function modulation.

Methods Used

This study employs in vivo methodologies in anesthetized rats to assess RSNA.
The biological model involves renal sympathetic nerves and addresses CNS manipulations.
Detailed surgical steps for catheter and electrode placements were outlined to ensure proper measurement.
Special attention was given to the quality of anesthesia and the positioning of the animals during procedures.

Main Results

The study successfully measured RSNA, demonstrating that CNS manipulations can impact renal sympathetic outflow.
Electrophysiological recordings confirmed changes in nerve activity correlated with blood pressure alterations.
Findings suggested that sympathetic nerve activity might play a role in regulating kidney function during CNS challenges.
The protocol validated by using phenylephrine injections to evoke baroreflex responses.

Conclusions

This study demonstrates a method for exploring CNS influence on renal sympathetic nerve activity.
The findings have implications for understanding autonomic regulation in cardiovascular health and disease.
The protocol can be adapted for future research on blood pressure control mechanisms.

Frequently Asked Questions

What are the advantages of this technique?

This method allows for precise measurement of sympathetic responses to central nervous system manipulations, providing valuable insights into autonomic regulation.

How is the biological model implemented?

The study uses anesthetized rats, where surgical techniques are employed to access and record renal sympathetic nerve activity.

What types of data are obtained from this method?

The methodology provides electrophysiological data regarding renal sympathetic nerve activity in response to CNS manipulations and blood pressure changes.

How can this method be adapted for other studies?

The protocol can be modified to examine different variables affecting sympathetic activity or to study various autonomic responses in other animal models.

What are key considerations when using this technique?

Ensuring adequate anesthesia, proper electrode placement, and handling of the animal during the procedure are critical for obtaining reliable results.

What limitations should be considered?

The method requires skilled surgical handling and may not be suitable for studies requiring long-term observations due to its acute experimental design.

Methods for measuring sympathetic and cardiovascular responses to central nervous system (CNS) manipulations are important for advancing neuroscience. This protocol was developed to assist scientists with measuring and quantifying acute changes in renal sympathetic nerve activity (RSNA) in anesthetized rats (non-survival).

This method can help answer key questions about the autonomic nervous system particularly about the central nervous system mechanisms that regulate sympathetic outflow to the kidney. The main advantage of this technique is that it allows measurement of the impact that central nervous system manipulations have on renal sympathetic outflow to the kidney. Before arterial cannulation, inspect the pressure sensing catheter under high magnification to confirm that the catheter is free of bubbles and debris and has an intact meniscus between the fluid and gel filled components.

Prior to each implantation, refill the gel at the distal tip of the catheter and use a magnet to turn on the transmitter. Place a loose overhand half knot in the proximal suture to briefly occlude the femoral artery. And holding the catheter introducer in the non dominant hand, use vessel cannulation forceps to grasp the tip of the cannula of the telemetry unit to avoid displacing the gel from the tip.

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