Subject(s)
Association , Multilingualism , Adult , Humans , Middle Aged , Reaction Time , Systems Theory , Word Association TestsABSTRACT
In anesthetized immobilised cats, stimulation of radial [correction of ulnar], sciatic and splanchnic nerves evoked responses in 91.85; 90.56 and 83.33 per cent of neurons, resp., in the associative medio-dorsal nucleus of the thalamus. A high degree of convergence (82.6%) of somatic and visceral signals was revealed, as well as the interaction between the signals by the mutually blocking type.
Subject(s)
Neurons/physiology , Peripheral Nerves/physiology , Thalamic Nuclei/physiology , Animals , Cats , Electric Stimulation , Microelectrodes , Proprioception/physiology , Radial Nerve/physiology , Reaction Time/physiology , Sciatic Nerve/physiology , Splanchnic Nerves/physiologyABSTRACT
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.
Subject(s)
Neurons/physiology , Thalamic Nuclei/physiology , Thalamus/physiology , Animals , Cats , Electric Stimulation/methods , Evoked Potentials , Microelectrodes , Neural Inhibition , Reaction Time/physiologyABSTRACT
Neuronal responses of the thalamic lateral posterior nucleus to single electrical shocks applied to radial, sciatic and splanchnic nerves, were studied in anesthetized immobilized cats. Different degrees of responsiveness (69, 63 and 51 per cent) and latencies (9-120, 12-130 and 16-130 ms) were revealed.
Subject(s)
Peripheral Nerves/physiology , Thalamic Nuclei/physiology , Animals , Association , Brain Mapping , Cats , Evoked Potentials , Radial Nerve/physiology , Reaction Time/physiology , Sciatic Nerve/physiology , Splanchnic Nerves/physiologyABSTRACT
High responsiveness of the center median neurons to stimulation of radial, sciatic and splanchnic nerves was found in unterstrained cats. The mean latencies of the responses were 24.1 ms, 28.4 ms and 38.4 ms, resp. A considerable convergence (up to 82%) was revealed. The inhibitory type of interrelationships prevailed among the afferents under study, being more obvious during the somatic stimulations. Theoretical aspects of these and other findings are discussed from the standpoint of the thalamic unspecific level of the somato-visceral integration mechanisms.
Subject(s)
Neurons/physiology , Thalamic Nuclei/physiology , Afferent Pathways/physiology , Animals , Cats , Electric Stimulation , Evoked Potentials , Radial Nerve/physiology , Sciatic Nerve/physiology , Splanchnic Nerves/physiologyABSTRACT
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.
Subject(s)
Peripheral Nerves/physiology , Thalamic Nuclei/physiology , Animals , Brain Mapping , Evoked Potentials , Guinea Pigs , Neural Analyzers/physiology , Reaction Time/physiology , Sciatic Nerve/physiology , Sensation/physiologyABSTRACT
Electrical stimulation of the cerebellar dentate nucleus elicits in neurons of the center median responses with either constant or altering latencies. The constant latencies ranged from 2-3 to 8-12 msec. Responses with altering latencies were more numerous and had the latencies up to 20 msec. In both responses with early and late components were recorded as well. Dentate stimulations induced "periods of inhibition" in CM neurons with leading duration of 50-100 msec. Synchronization of the SM unit activity during low-frequency stimulation was also revealed, in many cases it was preceded by the "periods of inhibition". Activity of 49% of reactive neurons during 1, 7-12, and 70-100/sec stimulations was facilitated, 31% depressed, and 20% had a mixed type of responses: facilitation on one frequency and depression on another. Immediate cessation of the effects after termination of stimulations was observed in 34% of neurons, while tonic influences were manifest in 66%.
