Hypoglycemic conditioned reflex in rats: preliminary study of its mechanism.

It was found that a nervous mechanism is involved in eliciting a hypoglycemic response in rats. A conditioned reflex was established after a series of reinforcements in which an insulin injection (unconditioned stimulus) was associated with the sound of a bell (conditioning stimulus). The hypoglycemic conditioned response was statistically similar to that of insulin. The latency of the beginning of the hypoglycemic response to insulin was between 4 and 6 min. The latency of the conditioned hypoglycemic response to the conditioning stimulus was about 1 min. Blood extracted from a conditioned rat during the test of conditioning produced a hypoglycemic effect when injected into a nonconditioned receptor rat.