STUDIES OF THE SENSORY-MOTOR RESPONSE IN RATS WITH INNATE HIGH-LEVEL OF ANXIETY

Sensory-motor response was measured by acoustic startle reflex in Wist ar male rats with innate high and low levels of anxiety. The levels of anxiety were determined using a complex multiparameter method for eva luating anxiety-phobic states in rats by a ranged scale. Amplitude and prepulse inhibition of the acoustic startle response were increased, but latency of the startle reflex was decreased in rats with innate hi gh level of anxiety as compared with those with innate low level. In r ats with innate high level of anxiety injection of subconvulsive doses of pentylenetetrazol (10 and 15 mg/kg i. p.) resulted in an increase of the amplitude of the acoustic startle response and, additionally (u nder the dose 10 mg/kg) in a decrease of its latency. Facilitation of acoustic startle in rats with innate high level of anxiety is suggeste d to reflect either a deficit of inhibitory, or intensification of exc itatory modulating influences on signal transmission in nerve circuit of acoustic startle. Studies of the sensory-motor response by acoustic startle in rats with innate high level of anxiety are believed to be useful for elucidating basic mechanisms of anxiety and phobia.