Abstract

Introduction

Laboratory Rats

Guinea Pigs

References

Discussion
Board

Infant mammals vocalize when removed from their mother and other aspects of their specific niche. These sounds have been viewed as a measure of separation distress, adaptive communication, and even a byproduct of thermoregulation. The specific environmental stimuli that influence crying are often subtle, differing across species, age, and sometimes even genetic strain. Whatever the level of analysis or interpretation, it is clear that infant crying behavior is composed of complex events involving a number of neural systems. The primary means of studying these systems has been through pharmacological manipulation. Neurochemical systems implicated in pharmacological studies of vocalizations in infant rats include the monoamines, opioids, GABA, acetylcholine, and corticotropin-releasing factor (CRF). In general, it appears that stimulation of the dopamine, serotonin, GABA and acetylcholine systems suppress vocalizing, and that norepinephrine agonists can facilitate vocalizing at younger ages. The effects of the opioid system are receptor dependent, with mu agonists reducing, and kappa agonists increasing, vocalizations. CRF suppresses vocalizing and may have a facilitative effect at low doses. Although these results were all obtained with the altricial rat, studies with the precocial guinea pig indicate some generality of effects, at least for opioids and CRF.

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Presentation Number SAkehoe0523
Keywords: