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Medial prefrontal cortical lesions modulate baroreflex sensitivity in the rat
A J Verberne1, S J Lewis, P J Worland
1University of Melbourne, Clinical Pharmacology and Therapeutics Unit, Heidelberg, Vic., Australia.
Brain Research
|November 24, 1987
Summary
The medial prefrontal cortex influences the baroreceptor heart rate reflex in rats. Lesioning this area reduced reflex gain, suggesting a descending excitatory pathway to the brainstem.
Area of Science:
- Neuroscience
- Cardiovascular Physiology
Background:
- The medial prefrontal cortex (mPFC) projects to the nucleus of the solitary tract (NTS).
- The NTS receives baroreceptor information from cranial nerves IX and X.
Purpose of the Study:
- To investigate the influence of the mPFC on the baroreceptor heart rate reflex in conscious rats.
Main Methods:
- Bilateral excitotoxin lesions of the mPFC were induced in rats.
- Baroreceptor reflex sensitivity was assessed using phenylephrine and sodium nitroprusside.
- Sigmoidal curve-fitting analyzed reflex parameters.
Main Results:
- mPFC lesions did not alter resting mean arterial pressure or heart rate.
- Lesions significantly reduced baroreceptor reflex gain (maximum and average).
- A minor decrease in the lower reflex threshold was observed post-lesion.
Conclusions:
- The mPFC modulates baroreceptor reflex gain.
- Findings suggest a descending excitatory projection from the mPFC to medullary centers involved in baroreflex regulation.