Functional blockade of the parabrachial area by tetrodotoxin disrupts the acquisition of conditioned taste aversion induced by motion-sickness in rats

The role of the parabrachial area in conditioned taste aversion (CTA) induc ed by motion-sickness was studied in male Wistar rats. In the first experim ent, one-trial conditioned taste aversion, to a 0.5% decaffeinated coffee s olution, was induced by 30 min of vertical rotatory motion (80 rev./min) in intact rats. In the second experiment, reversible blockade of the neural a ctivity in various brainstem sites was induced by bilateral intracerebral i njections of tetrodotoxin (TTX) (10 ng/mu l) after conditioning. Blockade o f the parabrachial area, but neither A8 nor lateral vestibular nucleus, dis rupted the acquisition of (CTA). The results are discussed in terms of an a ssociative role of the parabrachial area in body rotation-induced taste ave rsion learning, as the area was intact during sensory processing and testin g. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.