Showing papers on "Somatosensory system published in 1970"
1,690 citations
TL;DR: The postcentral hand area is identified by electrical stimulation, excised a small amount of tissue there, and later observed a mild disturbance of light touch, pressure, two-point discrimination, and position sense in the postcentral gyrus.
Abstract: ELECTRICAL stimulation of the cerebral cortex in conscious patients has shown the major cortical representation of somatic sensation to be in the postcentral gyrus, with a minor representation in the precentral gyrus. 1-4 On both sides of the rolandic fissure, the entire body form is represented in sequence, throat lying just above the fissure of Sylvius and toes at the midline. There is some debate, however, concerning the role of this central region in somatosensory discrimination, and the extent to which such discriminatory functions are focally represented in man's cortex. Early clinical reports described patients with small unilateral cortical excisions who showed partial interference with sensory function in the corresponding body parts. Thus, van Valkenburg 5 identified the postcentral hand area by electrical stimulation, excised a small amount of tissue there, and later observed a mild disturbance of light touch, pressure, two-point discrimination, and position sense in the
216 citations
TL;DR: The authors showed that the pattern of degeneration in layer IV of the striate cortex was indeed arranged in parallel stripes that alternated with zones of sparing, and postulated that the (striate) cortex can therefore be thought of as subdivided into slab-shaped columns with walls perpendicBrain Research, 23 (1970) 185-191.
135 citations
TL;DR: The findings suggest that human motor cortex plays a less important role in integration of disparate sensory inputs from the periphery than does motor cortex of lower animals.
94 citations
TL;DR: Short latency cortical evoked potentials to forepaw shocks were present in several rats which exhibited deficits n temperature discrimination or deviant responsiveness to foot shock.
27 citations
TL;DR: The threshold of the somatosensory evoked potentials inhyperthyroidism showed no significant changes, but on an increase in the stimulus strength, the amplitudes of the potentials increased much more abruptly in the hyperthyroid than in the normal subjects and reached a maximum at the motor threshold.
18 citations
TL;DR: Rats with histologically confirmed bilateral lesions of one or both somatosensory cortical areas, occipital cortex, or sham operations were tested in a T-maze, failing to reveal group differences on the three postoperative discriminations.
Abstract: Rats with histologically confirmed bilateral lesions of one or both somatosensory cortical areas, occipital cortex, or sham operations were tested in a T-maze for retention of 29° vs. 39° C and 29° vs. 34° C temperature discriminations, and for acquisition of a 29° vs. 31° C habit. Statistical analyses failed to reveal group differences on the three postoperative discriminations. The suggestion that thermal habits are mediated by a diffuse and redundant forebrain afferent system is discussed.
17 citations
TL;DR: It was found that hair-m neurons tend to concentrate lower in the cortex and discharge later in time than the hair-s and touch-s neurons, and the maximum total spike activity of thehair-s subset is bimodal and widely dispersed in time and depth.
15 citations
TL;DR: The pathway mediating corticofugal inhibition has its origin in areas in front of the Rolandic fissure, and it is suggested that the pathway is indirect and involves the bulbar reticular formation.
Abstract: Corticofugal inhibition of somatosensory transmission in the cuneate nucleus of monkeys under chloralose was investigated with particular reference to the time course of primary afferent depolarization (PAD), the cortical origin of its pathway, and its sensitivity to small additional doses of Nembutal. Corticofugal effects were also compared with PAD elicited by conditioning peripheral nerve stimuli. It is concluded that the pathway mediating corticofugal inhibition has its origin in areas in front of the Rolandic fissure. It is suggested that the pathway is indirect and involves the bulbar reticular formation.
14 citations
14 citations
TL;DR: The responses of individual neurons in the cerebral cortex of unanesthetized macaques to moving cutaneous stimuli are described and more complex concatenations of stimulus properties are described, as regards direction of stimulus motion and site of stimulus application on the body.
Abstract: The responses of individual neurons in the cerebral cortex of unanesthetized macaques to moving cutaneous stimuli are described. In somatic sensory area I, 70 percent of the neurons studied exhibit a directional polarization to stimuli moving in opposite direction. In somatic sensory area II, the magnitude of responses is determined by more complex concatenations of stimulus properties, as regards direction of stimulus motion and site of stimulus application on the body.
TL;DR: The large and consistent increase of SI negative response amplitude prior to seizures is a good predictor of seirure onset, consistent with previous suggestions that UDMH and other hydrazines block production of gamma-aminobutyric acid.
TL;DR: It is found that cortical neurones so excited usually respond with a long complex pattern of action potentials lasting from 140–2,000 ms.
Abstract: SINGLE cortical neurones have been reported to yield a short, high-frequency burst of action potentials in response to electrical stimulation of the contralateral body surface1–4. We have found, however, that cortical neurones so excited usually respond with a long complex pattern of action potentials lasting from 140–2,000 ms.
TL;DR: It was concluded that there is no direct functional dependence between the cells of the posterior and anterior portions of the red nucleus and the influence of dentate stimulation on cells in the anterior red nucleus was either direct excitation, inhibition, or a very weak facilitation on other responses.
Journal Article•
TL;DR: Evoked potentials can be elicited from all regions of the dorsal forebrain surface of the frog by electrical stimuli applied to the olfactory nerve in the form of a complex pattern with surface positive and surface negative transients, but optic and somatosensory stimuli do not trigger the discharge of epileptic foci in the same region.
Journal Article•
TL;DR: Investigation of unit activity of the cat somatosensory cortex has shown that the principal role in the genesis of the primary response, the response to stimulation of the thalamic relay nucleus, the callosal response, and certain other forms of evoked potentials of the somatosENSory cortex is played by neurons not usually responding by spike generation during EP development.
Abstract: Investigation of unit activity of the cat somatosensory cortex has shown that the principal role in the genesis of the primary response, the response to stimulation of the thalamic relay nucleus, the callosal response, and certain other forms of evoked potentials (EPs) of the somatosensory cortex is played by neurons not usually responding by spike generation during EP development. The EPs reflect what the cortical neurons received from the afferent volley, and the level of their polarization, but they are not a reliable indicator of fast nervous processes in the cerebral cortex. The EPs reflect postsynaptic potentials (PSPs) of neurons not directly participating actively in the analysis of information reaching the cortex.
01 Jan 1970
TL;DR: This experiment was designed to obtain somatosensory evoked potentials from the peripheral nerve, cauda equina, medial lemniscus (ML), ventralis posterior lateralis (VPL), and somatoensory cortex (SSC) of the macaque monkey under the influence of acute and chronic alcohol ingestion.
Abstract: Some studies have been conducted to determine the acute effect of ethanol on the electroencephalographic potential.1, 4, 5 However, little is known concerning the central or peripheral nervous system site of action of ethanol.3,4, 5 This experiment was designed to obtain somatosensory evoked potentials from the peripheral nerve, cauda equina, medial lemniscus (ML), ventralis posterior lateralis (VPL), and somatosensory cortex (SSC) of the macaque monkey under the influence of acute and chronic alcohol ingestion.
TL;DR: Evoked potentials in response to stimulation of the splanchnic and tibial nerves and to clicks are not recorded from all points of the caudate nucleus, indicating its heterogeneity relative to representation of different afferent systems, including the visceral.
Abstract: 1.
In response to stimulation of the splanchnic nerve, biphasic and multiphasic evoked potentials with relatively short (16–25 msec) and longer (30–54 msec) latent periods are recorded in the cat caudate nucleus.
2.
Evoked potentials in response to stimulation of the splanchnic and tibial nerves and to clicks are not recorded from all points of the caudate nucleus, indicating its heterogeneity relative to representation of different afferent systems, including the visceral.
3.
Extirpation of cortical somatosensory areas I and II, and also ablation of the neocortex, do not abolish evoked potentials in the ipsilateral caudate nucleus in response to splanchnic nerve stimulation.