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Biomedical subjects

K Grottel

Publications and source records attributed to K Grottel.

At least 73 records · Page 4Linked to original sources
PubMed1978

Dentritic range of the neurons of the intermediate gray at the levels of the first and second lumbar segments of the spinal cord in the cat. 3. The range of dendrites of the lateral region neurons.

The first and second lumbar segments of the spinal cord in kittens and mature cats were examined with Golgi method. It was found that the dendrites of large and medium neurons situated in the lateral region of the intermediate gray penetrated lamina V dorsally, and lamina VIII and motor nuclei ventrally. Laterally these dendrites reached the lateral horns and even the lateral funicles. Paracentrally they ran along the whole intermediate gray of the cord, entered the thoracic nucleus, and even the white commisure.

Animals↗
PubMed1978

Dentritic range of the neurons of the intermediate gray at the levels of the first and second lumbar segments of the spinal cord in the cat. 4. The range of dendrites of the lateral horn neurons.

The topography of dendrites of the lateral horn neurons at the level of L1--L2 have been investigated in young and mature cats using Golgi impregnation method. It has been stated that the dendrites of investigated neurons reach the lamina III (dorsally), the lateral funiculi (laterally), and the lateral and central parts of the intermediate gray (medially). They penetrate the thoracic nucleus as well. In their ventral course they were found within the laminae VIII and IX. Afferent connections of the neurons are also discussed.

Animals↗
PubMed1978

Alterations of dendritic spines following intoxication by mercury phenylacetate.

A morphological study of the effect of mercury phenylacetate (MPA) given intragastrically at a dose of either 0.1 or 0.05 g for 10 and 30 days respectively, on dendritic spines in the parietal cortex of the recipient rats was performed. Ingestion of MPA induced considerable losses as well as nodular deformation of dendritic spines in the investigated cortical region. The effect of MPA intoxication demonstrated in this study is discussed with respect ot histoenzymic observations made in another study on rats similarly intoxicated, in which a considerable drop of AChE activity in the cortical neuropil was demonstrated. It is concluded that the induced by MPA intoxication in dendritic spines, which constitute an integral part of the synaptic structures may be responsible for the observed decline of AChE activity in this experimental poisoning.

Acetylcholinesterase↗
PubMed1975

The spino - cerebellar tracts in rabbit.

In young mature rabbits the spinal cord was damaged within lateral funicles and adjacent parts of the dorsal and ventral funicles. After 5-8 days of survival, control examinations were performed to find the extension of the lesion of the spinal cord, as well as studies of the cerebellum by Nauta method to investigate the site of the changed nervous fibres. After injuring the spinal cord on the level of neuromer C3 the degeneration of nervous fibres was found on both side within the anterior and posterior lobes of the cerebellum. In the anterior lobe the degeneration referred to lobules I up to the anterior part of lobule V; in the posterior lobe it referred to lobule VIIIa, and VIIIb of the vermal zone, as well as to the adjacent parts of the hemispheres. When the spinal cord was damaged on the level of neuromer Th7 the degeneration of nervous fibres was seen in the same regions of the cerebellum, but mainly on the side of the lesion. When the spinal cord was damaged on the level of neuromer L2 the fibres changed by degeneration were met within the same regions of the anterior and posterior lobes of the cerebellum, but mostly on the side opposite the lesion. The changes were smaller in this region than in the two kinds of lesions discussed before. The results allow to assume that the ventral and dorsal spinocerebellar tracts end in the same regions of the cortex of the vermal zone and the intermediate zone of the anterior and posterior cerebellar lobe. The dorsal spinocerebellar tract seems to end on the same side, while the ventral spino-cerebellar tract ends almost exclusively on the opposite side of the symmetry plane.

Animals↗
PubMedDate not supplied

Projection to the lateral reticular nucleus from neurons located in C6-C7 segments of the spinal cord. An electrophysiological study in the cat.

Spinoreticular neurons projecting to the lateral reticular nucleus (LRN) were investigated electrophysiologically in the cervical enlargement of the cat spinal cord. Experiments were performed on alpha-chloralose anaesthetized animals. Antidromic action potentials were recorded extracellularly from cells located in C6 and C7 segments following stimulation of the ipsilateral LRN. The total sample included 50 neurons. Their cell bodies were found to be distributed in Rexed's laminae VI-VIII of the gray matter. Axonal conduction velocities ranged from 14.7 to 89.7 ms-1. Considerable differences between particular cases enabled two separate groups of slower and faster conduction to be distinguished. Values for these two groups were 14.7-44.3 ms-1 and 52.2-89.7 ms-1, respectively. Discrete differences with regard to the location of these groups were also pointed out. Such differentiation suggests that a proportion of axons from the slower conducting pool may be in fact collaterals of neurons that project to other brainstem centers or to lower levels of the spinal cord.

Action Potentials↗
PubMedDate not supplied

Spatial analysis of motor unit potentials of the rat medial gastrocnemius.

The spatial analysis of the potentials of single motor units of the rat medial gastrocnemius muscle evoked by stimulation of the fibres of split ventral roots was carried out with a bipolar electrode moving in the direction perpendicular to the longitudinal axis of the muscle fibres. During this movement of the electrode a variability was observed in the time of the biphasic potential from its maximum to minimum, and in the peak-to-peak amplitude of these potentials. The potentials recorded outside the territory of the motor unit had a lower amplitude in relation to the potentials from the territory of the unit. This made localization of the motor unit on the cross-section of the muscle possible. Differences in the duration of the potential from maximal to minimal amplitude (maximum-minimum amplitude time--M-MAT) of each investigated motor unit from successive recording sites reflected the number of fibres contributing to the action potential and the distance of the recording surface of the electrode from the zone of the motor end-plates of this motor unit. The greatest diameter of the territory of the observed motor units reached 2.5 mm.

Action Potentials↗