[Neuronal activity of cat thalamus reticular and relay nuclei]

The interaction between the unit activity of the thalamic reticular and relay nuclei was investigated on cats immobilized with tubarine. It was shown that unit activity of the relay nuclei can be significantly modulated by stimulation of the n. reticul. By simultaneous recording (with two microelectrodes) of the activity of thalamic reticular neurons the relay unit activity can be suppressed; during peripheral and cortical stimulations the alternation of excitation-inhibition of the thalamic reticular and relay units can be observed; excitation of thalamic reticular units can be associated with excitation of the relay nuclei units. Such types of interaction may also exist during simultaneous recording (by two microelectrodes) of the activity of the relay units and putative interneurons. Sometimes IPSPs with short latency (1 ms) were evoked in the thalamic relay nuclei during thalamic reticular stimulation. The existence of direct monosynaptic inhibition of the relay unit activity by the thalamic reticular units as well as inhibition by the activation of the putative interneurons of the specific thalamic nuclei is suggested.