A new experimental approach for detecting emotional and motivational changes produced by neuroactive compounds in rodents.

A new potential approach for detecting subtle changes of emotional and motivational states in rodents is represented by the analysis of ultrasonic vocalizations emitted in a variety of situations. The ultrasonic calls differ somewhat in their physical characteristics depending on the species and on the situation. The results of our studies on the effects of various neuroactive substances on ultrasonic emissions during neonatal life and during sexual behaviour are briefly described here together with what is known of the biological function of the calls.