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Biomedical subjects

I Lakos

Publications and source records attributed to I Lakos.

7 recordsLinked to original sources
PubMed1983

Separation of synaptic junctional complexes from thin layers of rabbit cerebral cortex.

Synaptic junctional fractions were separated from rabbit brain by procedures based on combining the methods of Cotman and Taylor [4], Orosz et al. [16, 17] and Lisman et al. [13]. Thin layers of cerebral cortices were homogenized to obtain a crude mitochondrial-synaptosomal fraction. The sedimentation rates of mitochondria and mitochondria containing synaptosomes were increased by raising the density of mitochondria with an insoluble dense formazan deposit inside mitochondria after iodo-nitrotetrazolium treatment. The synaptic plasma membrane fraction isolated by this method contained no mitochondrial contamination. After Triton X-100 treatment the insoluble residues of the detergent were centrifuged through discontinuous sucrose gradients. A great enrichment of morphologically identifiable intact synaptic junctions was observed in some of the obtained interface layers.

Animals↗
PubMed1980

Ultrastructural alterations in the initial segments and in the recurrent collateral terminals of Purkinje cells following axotomy.

Transection of Purkinje cell axons in adult male rats made 1.5 mm or further from the cell body does not lead to the death of the neuron and results in compensatory structural alterations of the surviving axonal portions of the nerve cell. Near to, and at the emergence of recurrent collaterals of Purkinje cell axons, huge varicosities filled with filaments, granular material, lysosomes and mitochondria develop. Terminals of recurrent axon collaterals also exhibit different degrees of structural changes. Most striking of the morphological alterations is the regular presence of nematosomes in the hypertrophic axonal branches, especially in synaptic terminals. Since nematosomes were shown to contain RNA in other types of neurons, their presence in recurrent collaterals may indicate an enhanced synthetic activity in Purkinje axonal processes and endings after axotomy.

Animals↗
PubMed1980

Myelinated dendrites of Purkinje cells in deafferented cerebellar cortex.

Following chronical (30--60 days) isolation of cerebellar vermis in developing and in adult rats, partially myelinated primary and secondary dendrites of Purkinje cells and myelinated Golgi, basket and stellate cell bodies were observed. The dendritic myelin sheaths were not continuous with but developed independently of preexisting axonal myelin. Experiments on rats and cats have additionally revealed that this redundant myelinization of Purkinje dendrites and of interneuronal perikarya can be elicited also by selective destruction of the olivocerebellar (climbing fibre) afferents, indicating a direct influence of climbing fibre afferentation on myelinization processes in the cerebellar cortex.

Afferent Pathways↗
PubMed1979

Identification of early glial elements as the precursors of Bergmann-glia: a Golgi-analysis of the developing rat cerebellar cortex.

The developing rat cerebellar cortex was studied by the rapid Golgi procedure in 200 mu thick slices and in 1--2 mu thick semithin sections poststained with toluidine-blue. Glial cells having radial fibres directed towards the pial surface were found to be present continuously in the internal granular layer during cerebellar maturation. This cell type was identified as the developing Bergmann-glia.

Animals↗
PubMed1978

A simple method for the determination of section thickness with high accuracy.

Using the partial carbon-coating of histological sections their thickness was determined by a relatively simple and accurate method. Calculations were based on the instrumental recording of the distance of focus change between the upper and lower section-surfaces. Determination of tissue refractive index was not required. Results compared favourably with those of more complicated techniques.

Histological Techniques↗