Endogenous Changes in Hibernation-specific Protein in Chipmunk Cerebrospinal Fluid

Abstract

Hibernation-specific: protein (HP) which was found in the blood of chipmunks (Tamias sibiricus asiaticus), a rodent hibernator, has been demonstrated to be downregulated by differential gene expression in the liver in association with an endogenous circannual rhythm. In the present paper, we investigated the existence and the structural properties of HP in cerebrospinal fluid (CSF) from the lateral ventricle. A much less amount of HP was detected in CSF in nonhibernating slate. HP in CSF was markedly increased in association with a circannual rhythm of hibernation and structurally differed from HP in plasma. A similar increase in WP in CSF was induced by the administration of thyroxine that has been shown to cause the change in HP contents in plasma as seen during hibernation. These results suggested that HP plays a role in the brain during hibernation through structural changes, Thyroxine may be involved in the regulation of HF during hibernation.