Influence of descending forebrain projections on processing of acoustic signals and audiomotor integration in the anuran midbrain.

We tested the role of descending projections for auditory processing and audiomotor integration in the anuran torus semicircularis. Intracellular recordings were made from isolated brain preparations, impaled neurons were stained. Auditory neurons responded to electrical stimulation of striatum and/or dorsal thalamus, they integrated forebrain and auditory nerve inputs. High frequency stimulation in striatum or thalamus changed the auditory response of torus neurons located in the laminar subnucleus. Our results suggest that the laminar nucleus is the primary target of forebrain projections, which provides a basis for modulation of acoustically guided behaviour.