Role of Lipids in the Assembly of Endoplasmic Reticulum and Dictyosomes in Neuronal Cells from the Cerebral Cortex of Yakutian Ground Squirrel (Citellus undulatus) during Hibernation

摘要: Phospholipids and cholesterol were assayed in homogenates microsomal fractions from the cerebral cortex of summer-active, winter-torpid, winter-active Yakutian ground squirrels (Citellus undulatus). Ultrastructural analysis both fraction intact neurons was performed by serial ultramicrotomy. The levels sphingomyelin (SM), phosphatidylserine (PS), phosphatidylethanolamine (PEA) decreased winter compared with summer-active animals, while phosphatidylcholine (PC) cardiolipin (CL) increased. level winter-torpid animals total phospholipids comparison to animals. Three-dimensional reconstruction membrane profiles displayed be an interconnected system cisterns vesicles, which corresponds endoplasmic reticulum dictyosomes (Golgi stacks) neurons. In content PC increased fraction, contents lysophosphatidylcholine (LPC), PS, phosphatidylinositol (PI), SM decreased. ones phospholipids, PEA, LPC, As for squirrels, their lipid did not differ those but LPC changes pyramidal throughout hibernation accompanied disassembly (ER), including decomposition polyribosomes monosomes. ultrastructural nucleoli, ER, torpid showed a direct correlation between increasing (mainly PEA LPC) microsomes structural recovery reticulum, Golgi stacks, nucleoli A role seasonal variations brain cells adaptation low temperature is discussed. We also propose involvement activation protein-synthesizing function stacks