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Results for “Sensorimotor Cortex”

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At least 595 records · Page 33Linked to original sources
PubMed1982

[Effect of acoustic stress on morphology of rat sensorimotor cortex].

The structure and ultrastructure of the sensomotor cortex in pubertal rats were studied 7, 14 and 21 days after acoustic stress. Focal peripheral chromatolysis and pigment accumulation by lysosomes were found in neurons after 14 and 21 days of exposure to noise. The number of lysosomes in which pigment was accumulated, and multivesicular bodies appeared, increased in the glial cells. The cavities of granular reticulum widened because of the accumulation by them of muddy secretion. These phenomena indicate the diffusive character of structural changes in the cortex of the large hemispheres under acoustic stress. It has been noted that young animals exposed to noise manifest changes characteristic of the process of aging.

Animals↗
PubMed1982

[Effect of opioid peptides, morphine and electroacupuncture on the neuronal activity of the sensorimotor cortex and brain stem reticular formation].

Experiments were made on unanesthetized rabbits and cats to examine the neuronal response (the sensomotor cortex, mesencephalic reticular formation, giant cell reticular nucleus of the medulla oblongata) to microapplications of enkephalins, endorphins, morphine, and electroacupuncture. Opiate peptides, morphine, and electroacupuncture produced similar, unidirectional changes in both spontaneous and nociceptive-stimulated neuronal activity. Naloxone removed these reactions. It is assumed that in the brain structures under study, the electroacupuncture effects are mediated by opiate receptors and are linked with enkephalin and endorphin release.

Acupuncture Therapy↗
PubMed1980

[Ultrastructure of the functional element links of the sensorimotor cortex in endotoxic shock].

Endotoxin shock in rabbits and dogs was induced by intravenous administration of endotoxin B. typhosus. Dystrophic changes and hemodynamic disturbances with dilatation and hyperemia of capillaries, increasing permeability of blood-brain barrier were observed in light microscopy of the brain sensomotor cortex. Ultrastructural alterations in neurons were characterized by swelling and destruction of mitochondria, hypertrophy of Golgi complex, increasing lysosome number. In cytoplasm of astrocytes the glycogen disappeared, the secondary lysosomes increased in number. There was a vacuolar dystrophy in olygodendrocytes. These changes were resulted from the shifts occurring in fine structure of capillaries. Hypoxia played an important role in disturbances of the brain integrative activity.

Animals↗
PubMedDate not supplied

[The ultrastructural characteristics of the synapses in the rat sensorimotor cortex under the action of different adverse factors].

Ninety six outbred males of albino rats of 10-14 months of age were subjected to modeling experimental cerebro-vascular deficiency and were exposed to low frequency vibration and hypokinesia. Ultrastructural changes in neurons and synapses of sensomotor cortex were studied using electron microscopy. It was found that exposure to all harmful factors led to similar ultrastructural changes in soma of neurons and may be considered as hypoxic changes. Lesions in synaptic system depends on the type of the influence. Thus, permanent cerebro-vascular deficiency resulted in increase in light synapses number. Low frequency vibration was accompanied by appearance of synapses with shortened active zone and synapses with great amount of independent vesicles. Hypokinesia was accompanied by appearance of synapses with prolonged active zone and synapse in astrocyte muffs.

Animals↗
PubMedDate not supplied

[Changes in the ultrastructural indices of the axospinal synapses and in the reactions of long-term posttetanic potentiation in surviving slices of mouse sensorimotor cortex].

Electron microscopic and morphometrical methods were used to study axospinal synapses as well as reactions of continuous posttetanic potentiation of neurons in surviving slices of sensomotor cerebral cortex in white mice. Under the same experimental conditions electron microscopic and electrophysiological studies have established that the result of high frequency electrical stimulation consisted in the appearance of continuous posttetanic potentiation, and quantitative and morphometrical changes in the ultrastructure of axospinal synapses: decreased active zone, increased summary greatest width of the spine apparatus cisterns. A supposition is made that high frequency electrical stimulation results in changed content of Ca2+ in spine cytoplasm, which may be considered as a trigger factor influencing the changes of cable properties and synaptic efficiency of axospinal synapses at the initial period of the continuous posttetanic potentiation.

Animals↗
PubMed1993

[The influence of pyramidal tract pathway of sensorimotor cortex on the effects of acupuncture analgesia on NRM neurons].

The experiment was to study whether the effects of electroacupuncture (EA) on neurons in nucleus raphe magnus (NRM) were influenced after lesion of bilateral pyramidal tracts (PT) in the rats. Unit discharges of NRM were recorded extracellularly with glass microelectrodes, and their nociceptive responses were induced by train electro-stimulation of tail. It was researched only the neurons with excitory response to noxious stimulation of the tail. 1. The effects of bilateral 'Zusanli' acupoint on 31 NRM neurons were observed in control group. EA had a tendency to activate NRM neurons, but inhibited obviously nociceptive response of the neurons at 0-30 minutes (P < 0.01). The effects of EA of PT control group (PT exposed and kept intact) were recorded on 8 units in NRM. EA had a tendency to activate the neurons, but inhibited obviously nociceptive response of the neurons and decreased nociceptive response rate 25.3 +/- 8.7% at 0 minute (n = 8, P < 0.05) 3. EA after the PT lesion, it obviously inhibited nociceptive response of the neurons in NRM at 0-20 minutes (n = 9, P < 0.01-0.05). It inhibited nociceptive response of all the neurons and decreased nociceptive response rate 57.8 +/- 11.6% at 0 minute (P < 0.01). The effect was larger than the effect of EA of PT control group and increased 32.5% at 0 minute (P < 0.05) than this. It also increased the effect of EA activating the neurons than PT control group. The results suggest that SM may influence the effect of EA analgesia, which involves in both PT and extrapyramidal system (EPS).(ABSTRACT TRUNCATED AT 250 WORDS)

Acupuncture Analgesia↗
PubMedDate not supplied

[The effect of moderate doses of ethanol on the nature of the background neuronal impulse activity of the sensorimotor cortex in rats].

The influence of acute administration of moderate doses of ethanol (170-1200 mcg/kg, intraperitoneally) on the spontaneous impulse activity of motor cortex neurons was studied in outbred rats never earlier exposed to alcohol. Initial reactions of the cortical neurons were shown to be characterized by the changes in the frequency of spontaneous activity which could be increased or decreased during the first 20-25 min after the injection. The changes in the mean frequency of spontaneous discharges were accompanied by the changes in their patterns. Both increase and decrease of the mean frequency at the initial stage of ethanol action was accompanied by significant variability of interspike intervals. It is emphasized that examination of the initial reactions of the cortical neurons to ethanol administration demands studying their temporal duration.

Animals↗
PubMedDate not supplied

[A morphometric study of the ultrastructure of the axosomatic synapses in the sensorimotor cortex of rats administered the delta-sleep inducing peptide].

Qualitative estimation and quantitative morphometry of ultrastructural changes in layers III, IV, and V in rat sensomotorial cortex after delta-sleep-inducing peptide administration, provides an evidence of multiplication of active inhibitory synapses induced by DSIP. The newly activated synapses may form an axo-somatic synaptic pool participating in optimization of the balance of excitement and inhibition processes in sensomotorial cortex.

Animals↗
PubMed1993

[The dendritic plasticity of the pyramidal neurons in layer V of the rat sensorimotor cortex in the postischemic period].

Dendrites plasticity of pyramidal neurons in layer V of rat sensomotor cortex was analyzed during postischemic period. Oblique dendrites and their spines of pyramidal neurons were more reactive for ischemia after 1 day aa manifested by decrease in their length, branching, the volume of dendritic territory and number of dendritic spines. This testifies to high sensitivity to the ischemic influence of stimulating aditus of pyramidal neurons of layer V in the sensomotor cortex of rat. At 7 days of postischemic damage, dendrites of pyramidal neurone were mostly reduced. The quantitative parameters of dendritic geometry recovered after 30 and 90 days of ischemia.

Animals↗