Biomedical subjects

C Colasante

Publications and source records attributed to C Colasante.

21 records · Page 2Linked to original sources

PubMed1983

Morphological changes in neuromuscular junctions during exercise.

Long lasting exercise produces several morphological changes in teleostean neuromuscular junctions (NJs), consisting of progressive synaptic vesicles (SVs) depletion and lamellar branching of the nerve endings. Exercised fishes kept swimming during 1 hr against a 3.5 1/min flow of oxygenated water in spite of the fact that the number of SVs was reduced in about 70% after 10 min of exercise. This observation indicates that the SVs formation fails to restore their original number and consequently, under such circumstances, the transmitter release may occur by a different mechanism.

Animals↗

PubMedDate not supplied

Synaptophysin (p38) immunolabelling at the mouse neuromuscular junction.

The synaptophysin (p38), a transmembrane glycoprotein of synaptic vesicles, has been used as a marker in order to study the membrane events that take place during transmitter release at the mouse neuromuscular junction (NMJ). p38 has been labelled by immunofluorescence using a monoclonal anti-p38 antibody and fluorescein-conjugated IgG on dissociated muscle fibres (biceps brachialis m.). Its localization has been compared to that of the acetylcholine (ACh) receptors labelled with rhodaminated alpha-bungarotoxin. A weak labelling was obtained in nerve-muscle preparations at rest only when the muscle fibres were permeabilized with Triton X-100. By contrast, an intense immunofluorescence of the NMJ was observed after an exhaustive ACh release induced by Cd2+ in Ca(2+)-free medium, which leads to a synaptic vesicle depletion and an increase in the membranous structures in nerve terminals. Treatment with Cd2+ in Ca(2+)-free solution leads to both synaptic vesicle depletion and p38 immunolabelling, which is in favour of synaptic vesicle fusion and incorporation into the axolemma.

Acetylcholine↗

PubMedDate not supplied

Ultrastructural investigation of human sperm using atomic force microscopy.

Ultrastructural investigation of human sperm in its natural environment (without fixation, dehydration, embedding, sectioning, etc.) was carried out by using atomic force microscope (AFM) in its tapping mode. This technique permits the examination of fine structural details of undamaged sperm and its topography with precision. Moreover, it allows 3D reconstruction of images and enhances the contrast to resolve details such as mitochondria that surround the axoneme at the sperm middle piece. An organized structure has been found in the flageller axoneme region. Ultrastructure also reveals folding and details of the depression of the membrane that cannot be examined with conventional techniques.

Humans↗