Neuronal organization of rat thalamus for processing information of vibrissal movements.

Vibrissa-responding neurons were searched for in the somatosensory part of the thalamic reticular nucleus (S-TR) and in the ventrobasal nucleus (VB) in urethane-anesthetized rats. More than 90% of the recorded neurons of both species had receptive fields (RFs) on single vibrissae. Movements of RF-vibrissae produced a burst of multiple discharges in S-TR neurons and single spike discharges followed by a prominent suppression of spontaneous discharges in VB neurons. Antidromic invasion from stimulation of the somatosensory cortex in VB neurons was suppressed after RF-vibrissae were stimulated. A possible functional organization comprising VB and S-TR neurons for processing impulses of vibrissal movements was suggested.