Medullary cardiovascular effects of tetrodotoxin in anaesthetized cats

Tetrodotoxin injected in the cat nucleus tracus solitarii produced hypertension without bradycardia, whereas in the nucleus reticularis lateralis it led to hypotension and bradycardia. Tetrodotoxin acts by blocking neuronal activity; it is a useful tool for studying the central organization of cardiovascular regulation. The present data confirm that the nucleus reticularis lateralis is a vasopressive centre.