[Characteristics of representations of the auditory and somatosensory systems in the thalamus of the turtle: electrophysiologic study].

Experiments with unanesthetized tubocurarine-immobilized turtles show that the auditory representation is localized in the n. reuniens which contains monomodal (auditory) and bimodal (auditory and somatosensory) units. The somatosensory system is represented wider, overlapping the auditory system projections in the lateral parts of n. reuniens. The focus of the somatosensory representation is localized in the n. ventralis where monomodal somatic units were recorded. A predominance of contralateral somatic projections is revealed as well. A range of optimal frequencies was 200-400 Hz. It is shown that the thalamic neurons have both wide and limited receptive fields to auditory and somatosensory stimulations.