Recognition of mother's voice evokes metabolic activation in the medial prefrontal cortex and lateral thalamus of Octodon degus pups

In a variety of animal species, including primates, vocal communication is an essential part to establish and maintain social interactions, including the emotional bond between the newborn, its parents and siblings.(3,12,22,30) The aim of this study in pups of the trumpet-tailed rat, Octodon degus,was to identify cortical and subcortical brain regions, which are involved in the perception of vocalizations uttered by the mother. In this species, which is characterized by an elaborated vocal repertoire,(3,22) the (C-14)-2-fluoro-deoxyglucose autoradiography was applied to measure region-specific metabolic activation in response to the presentation of a learned emotionally relevant acoustic stimulus, the maternal calls.(3),(22) Already at the age of eight days the precentral medial cortex, anterior cingulate cortex and the lateral thalamus could be identified by their enhanced metabolic activation in response to the presentation of the emotionally relevant maternal nursing calls, whereas other brain areas, such as the hippocampus and amygdala did not show stimulus-induced activation. Since in humans changes of activity patterns in relation to the emotional content of spoken language have been observed in similar brain regions, e,g, in the anterior cingulate cortex,(7,16,17) Octodon degus may provide a suitable animal model to study the cellular and synaptic mechanisms underlying perception, production and processing of conspecific vocalizations, (C) 2001 IBRO, Published by Elsevier Science Ltd. All rights reserved.