SENSORY-MOTOR INTERFACING IN ACOUSTIC BEHAVIOR OF ANURANS

Anurans respond to different acoustic signals in a distinct manner. Mo reover, acoustic behavior strongly depends on the inner state of the a nimal and the social context. Neuroanatomical studies as well as extra - and intracellular recordings were carried out to examine the problem of audio-motor interfacing. Acoustic signals are processed in a partl y hierarchical and partly distributed manner in the anuran central ner vous system. Features are represented in a topographical manner. Audit ory maps in the midbrain torus semicircularis are read by a subset of neurons of the laminar and magnocellular subnuclei, which interconnect the auditory pathway and premotor centres. These, in turn, feed into neural networks controlling vocalization, locomotion, or autonomic fun ctions. Our data on the cytoarchitectonic organization and connectivit y of the interfacing neurons give rise to a population coding hypothes is which may explain the differential evaluation of acoustic signals. Additionally, immunohistochemical findings reveal strong neuromodulato ry and hormonal input, especially onto interfacing neurons, suggesting intense influence on the physiological properties of these cells.