Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In these studies we have investigated factors that might account for two previous observations of the ventral glial limitans subjacent to the supraoptic nucleus (SON-VGL) of dehydrated rats: (1) a reversible reduction in the thickness of the SON-VGL, and (2) a reversible reorientation of VGL astrocytes. Since components of the basal lamina influence both cell viability and polarity, we used electron microscopic sterology to determine the volume fraction of basal lamina in the SON-VGL. We further made extensive measurements of astrocytic process thickness to determine if cellular shrinkage is a factor in the thinning of the SON-VGL. While we found no evidence for changes in the thickness of astrocytic processes, there was a significant and reversible reduction in the extent of the basal lamina. These data suggest that the thinning of the VGL is due to complex biochemical events and is not merely an epiphenomenon of dehydration.
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PMID:Dehydration-associated changes in the ventral glial limitans subjacent to the supraoptic nucleus include a reduction in the extent of the basal lamina but not astrocytic process shrinkage. 1061 59

Two previous studies from our laboratory have indicated that the ventral glial limitans subjacent to the hypothalamic supraoptic nucleus (SON-VGL) undergoes a reversible thinning upon chronic activation of the magnocellular neuroendocrine cells (MNCs) of the supraoptic nucleus (SON). Numerous other studies have shown that MNC somata hypertrophy with activation. One aim of the current study was to understand better how SON-VGL thinning occurs. A second aim was to quantify overall changes of the MNC somata region due to cellular hypertrophy to compare relative changes in dimensions. Here, we undertook a light microscopic stereological investigation of the SON and the subjacent SON-VGL of Nissl stained material under basal and activated conditions. Astrocyte numbers in the underlying SON-VGL remained stable across hydration state as did the overall volume of the SON-VGL and dendritic zone reference area. How these data are consistent with our earlier observations of SON-VGL thinning was resolved by the finding of a highly significant, 30% increase in the mediolateral dimension of the SON-VGL in dehydrated rats. These observations fit well with previous work from our laboratory that demonstrates a reorientation of SON-VGL astrocytes, from vertical to horizontal, which occurs in the activated SON-VGL. We found a significant, approximately 54%, increase in the overall volume of the MNC region of the SON. No significant rostrocaudal lengthening of the SON was detected, although a trend was evident. All the observed changes reversed with rehydration. These data indicate that elasticity of the SON-VGL acts to accommodate the volume expansion of the MNCs and enables the SON-VGL to continue as an interface between the underlying cerebrospinal fluid in the subarachnoid space and the expanded SON above.
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PMID:Glial limitans elasticity subjacent to the supraoptic nucleus. 1527 Oct 58