SLOWING OF THE HEART AS A CONDITIONED REFLEX IN THE RABBIT

Abstract

The rabbit can be conditioned to lower its heart rate to nearly 2/3 its normal resting rate, e.g., from 230 beats/min. to 162, for a period of about 3 sec., by using inhalation of ammonia as the unconditioned stimulus and the ringing of a bell as the conditioned stimulus.