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Biomedical subjects

A Violante

Publications and source records attributed to A Violante.

At least 37 records · Page 2Linked to original sources
PubMed1980

[Importance of the degeneration of afferent components of the hypoglossal nerve on the reflex activity of the nucleus of the hypoglossal nerve in the frog].

The section of frog XII cranial nerve facilitates the reflex activity given by its nucleus. Since this positive effects is not dependent upon any motoneurons degeneration, the hypothesis has been put forward that only the afferent component of the XII nerve is able to modulate the reflex activity by means of PAD effect at the solitarius nucleus. This hypothesis has been tested examining the effect both on the glossopharyngeal reflex response and on the DRR following excision respectively of the dorsal root and of the whole hypoglossal nerve. In preparations with a XII dorsal root transected, electrical stimulation of the homolateral glossopharyngeus nerve evoked a much more intense reflex response than at the intact side. The same effect was evident after the section of the whole nerve.

Animals↗
PubMed1980

Functional importance of the taste papillae of Phormia regina M.

Electrophysiological recording from taste papillae of Phormia regina M. after stimulation with sugar (sucrose, glucose, fructose and galactose) and salt solutions (NaCl, KCl, KNO3 and CaCl2) has indicated that: 1) in all cases the responses showed a phasic onset about 30 sec in duration; 2) after sugar stimulation the phasic onset of the response was followed by a slow adapting tonic period; 3) no tonic period was present after NaCl, KCl, or KNO3 stimulation; 4) CaCl2 evoked a typical volleying activity that can be explained by a greater spatial spreading of electrotonic currents. These results indicate that the proboscis can only be maintained in an extended position (enabling food to be ingested) by rithmic firing from the papillae.

Animals↗
PubMed1980

[Activation of afferent pathways and of control frog olfactory bulb and extracellular field potentials].

It has been recorded the extracellular field potentials of the frog's olfactory bulb produced by electrical stimulation of the commissura anterior and small branches of the olfactory nerve. The activation of the commissural system obtain a positive, long-lasting field potential generated at the soma of the granular cells. The olfactory nerve stimulation produce also a positive surface wave bath at the end of bulbar reply: this effect can be attributed to the activation of the bulbar component of commissural system at the NOA. The recognizable electrical effects of the commissural system allow to make clear the sources of the extracellular field potentials in the bulbar neuronal circuits.

Action Potentials↗
PubMed1974

[An ultrastructural research of pancreatic islets in sodium nitrite poisoned rabbits (author's transl)].

Following a biochemical and histological study, the pathogenic effects of the sodium nitrite were investigated by the electron microscope. The vasodilator effect of the nitrite causes in the islets edema and dilatation of the sinusoids. We suppose that the increased afflux of blood could favour the secretion of granules till the exhaustion of cells. Moreover, the endoplasmic reticulum becomes more and more homogeneous and finally he loses its characteristic structure. We observed, at last, that the number of pancreatic islets in the poisoned animals is lower than in control animals.

Animals↗