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Biomedical subjects

O Narkiewicz

Publications and source records attributed to O Narkiewicz.

69 records · Page 4Linked to original sources
PubMed1972

Frontoclaustral interrelations in cats and dogs.

In 13 cats and 5 dogs various parts of the frontal lobe were removed. As a result terminal degenerations in the rostral quarter of the insular claustrum were found by Nauta and Fink-Heimer II methods. In cats with motor cortex lesions, the degenerations were localized more dorsally than in cats with removals of the frontoorbital cortex, but there is a large overlap between degenerating areas of the claustrum in both groups of animals. In the dog it even seems possible to differentiate claustral regions in which axons from various gyri of the frontal lobe mainly terminate. It was found under the electron microscope that degeneration affects asymmetrical axodendritic synapses which make contacts with small dendritic branches. Comparing these results with severe cellular degenerations found in the claustrum following large neocortical removals it seems that the rostral part of the claustrum is abundantly interconnected with the frontal cortex and interrelations between the frontal granular cortex and claustrum may be considered as close. There are two hypotheses concerning frontoclaustral relations: either the rostral pole of the claustrum belongs, like the dorsomedial nucleus of the thalamus mainly to the frontopetal ascending system which has frontoclaustral feedback connections or it is incorporated into a descending system through which the frontal cortex controls the functions of other subcortical structures.

Animals↗
PubMedDate not supplied

Somatosensory evoked potentials following lesions of the claustrum.

Ipsi- and contralateral cortical somatosensory evoked potentials (SEP) were recorded following median nerve stimulation in 12 patients with unilateral brain lesions and in 5 healthy subjects. Computed tomographic scans of brain were performed on admission. In all patients with lesions of the claustrum there was absence of SEP contralateral to the side of the lesion and ipsilateral to the stimulated nerve. This phenomenon did not appear in our material following lesions involving other structures e.g. thalamus or somatosensory cortex. Our observations suggest that the claustrum may influence deeply the contralateral somatosensory cortex. This may be due to the fact that a large part of the claustrum is involved in transmission of the sensory information from receptors to the somatosensory cortex.

Brain Injuries↗