[Rostral ventrolateral medulla-sympathetic vasoconstrictor nerve system mediated insular cortex-pressor response]

Area of Science:

• Neuroscience
• Cardiovascular Physiology
• Autonomic Nervous System Research

Context:

• The insular cortex (INS) plays a role in cardiovascular regulation.
• Understanding the neural pathways controlling blood pressure is crucial for treating hypertension.

Purpose:

• To investigate the neural mechanisms underlying the pressor response elicited by L-glutamate stimulation of the insular cortex.
• To determine the involvement of the rostral ventrolateral medulla (RVL) and specific receptor types in this response.

Summary:

• Microinjection of L-glutamate into the rat insular cortex induced significant increases in blood pressure and heart rate.
• Pharmacological blockade of alpha-, beta-, and M-receptors in the rostral ventrolateral medulla attenuated this pressor response.
• Intravenous phentolamine, but not propranolol or methyl atropine, also reduced the pressor effect, suggesting a role for sympathetic vasoconstrictor nerves.

Impact:

• These findings elucidate the role of the insular cortex and RVL in sympathetic cardiovascular control.
• Identifies specific receptor subtypes (alpha, beta, M) within the RVL involved in mediating the pressor response.
• Provides a foundation for exploring novel therapeutic targets for autonomic dysfunction and cardiovascular diseases.