Morphological response of endoplasmic reticulum in cerebellar Purkinje cells to calcium deprivation.
Mobilisable intracellular Ca2+ stores are highly enriched in the cerebellum, particularly in Purkinje cells. We have detected, by light and electron microscopy, striking morphological changes in the presumed Ca2+ stores of Purkinje cells when slices of eight-day-old rat cerebellum were incubated in Ca(2+)-deficient media. After 30 min under these conditions, the endoplasmic reticulum became thinned and elongated. By 2 h, it was transformed into multilamellar, whorl-like inclusions with electron-dense cores. These changes were reversed on reintroduction of Ca2+. Analogous changes in other neurons were not observed. The results suggest that Ca2+ storage sites within Purkinje cells are capable of dramatic morphological change depending on the availability of Ca2+. The transformations may reflect, initially, depletion of Ca2+ from the stores and then homeostatic alterations in their capacity.
Garthwaite
G
G
Department of Physiology, University of Liverpool, U.K.
Hajos
F
F
Garthwaite
J
J
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002525:Cerebellar Cortex / Q000166:cytology / Q000648:ultrastructure; D002529:Cerebellar Nuclei / Q000166:cytology / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000502:physiology / Q000648:ultrastructure*; D066298:In Vitro Techniques; D011689:Purkinje Cells / Q000502:physiology / Q000648:ultrastructure*; D051381:Rats; D011919:Rats, Inbred Strains
D002118:Calcium