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.
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.
Salm
A K
AK
Department of Anatomy, West Virginia University School of Medicine, Morgantown 26506-9128, USA.
Bobak
J B
JB
D000818:Animals; D001253:Astrocytes / Q000473:pathology / Q000502:physiology / Q000648:ultrastructure; D001485:Basement Membrane / Q000473:pathology / Q000503:physiopathology / Q000648:ultrastructure; D016764:Cell Polarity; D002470:Cell Survival; D003681:Dehydration / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D009473:Neuronal Plasticity; D051381:Rats; D013495:Supraoptic Nucleus / Q000473:pathology / Q000502:physiology / Q000503:physiopathology*; D013997:Time Factors