[Effect of stimulation of the thalamic reticular nucleus on the neuronal activity of the associative and nonspecific structures of the thalamus]. / Vliianie razdrazheniia retikuliarnogo iadra talamusa na aktivnost' neironov assotsiativnoi i nespetsificheskoi struktur talamusa.

Neuronal responses in center median, medial dorsal and posterior lateral nuclei to the stimulations of n. reticularis were studied in restrained cats. 53.7, 48.3 and 10%, resp., of the units were affected. Phasing character of "silent" neurons' EPs as well as the responses with primary or secondary inhibitory periods of spontaneously firing units, were demonstrated. A wide variety of the response latencies was revealed in the n. CM (5-33.6 msec; mean: 14.83 +/- 1.7 msec) and the n. DM (3.5-44.8 msec; mean: 18.03 +/- 2.5 msec) neurons. A significant convergence of the n. reticularis and somatovisceral inputs in the neurons of the same nuclei (52.83% and 53.5%, resp.) as well as inhibitory type of interaction between these inputs, were revealed.

[Study of thalamic input in the motor area of the cat cortex by means of retrograde axonal transport of horseradish peroxidase]. / Izuchenie talamicheskikh vkhodov v dvigatel'nuiu zonu kory bol'shikh polusharii mozga koshki s pomoshch'iu retrogradnogo aksonnogo transporta peroksidazy khrena.

HRP-labelled neurons were studied in different thalamic nuclei projected to anterior pericruciate motor cortex of cats. Considerable concentrations of labelled cells were found in the rostral parts of relay nuclei (VL, VPL, VPM). A local type of distribution of such neurons in the associative MD nucleus was discovered as well. The quantity of HRP-labelled units in the intralaminar nonspecific nuclei (Cl, Pc, CM) was small and they were diffusively distributed. Some aspects of heterogenic thalamic afferentation to the motor cortex are discussed.

[Convergence and interaction of somatic and visceral inputs in the neurons of the ventral posterolateral nucleus of the thalamus]. / Konvergentsiia i vzaimodeistvie somaticheskoi i vistseral'noi impul'satsii na neironakh ventral'nogo zadnelateral'nogo iadra talamusa.

Unit activity and field potentials recorded in the cat thalamic VPL nucleus in the radial and splanchnic nerves stimulations, revealed a distinct preference in localization of responses in the mediocentral and centrolateral areas of the nucleus, as well as similarities and differences in the patterns of responses to different types of stimulation. The convergence (particularly during long-latency responses) mostly occurred in the central areas. Inhibitory character of interactions between somato-visceral stimulations was more obvious during conditioned stimulation of the radial nerve.

[Electrophysiologic study of somatic representation in Cavia cobaya guinea pig thalamus]. / Elektrofiziologicheskoe izuchenie somaticheskogo predstavitel'stva v talamuse morskoi svinki Cavia cobaya.

The effects of stimulation of the sciatic nerve and ipsilateral thalamic parafascicular nucleus on the thalamic posterior nucleus have been investigated by recording both the evoked potentials (EP) and neuronal activity in guinea pigs under light chloralose or nembutal anaesthesia. Animals were immobilized by d-tubocurarine and kept under artificial respiration. Widely spread EP to sciatic stimulation were recorded with a latency of about 10-60 ms. In most cases they had a positive-negative configuration which was followed by a secondary wave of a complex composition. Simultaneously recorded neuronal firings had a group character and primarily were related to the positive component or to the onset of the negative component of the EP. Both the EP and neuronal responses to stimulation of the parafascicular nucleus had mainly short latencies (3-12 ms) and monophasic negative configuration. The inhibitory effect of conditioning stimulation of the parafascicular nucleus on somatically evoked responses was demonstrated as well.