corticotropin-like-intermediate-lobe-peptide and Sleep-Wake-Disorders

It is now known that after an immobilization stress (IS) of short duration (1h), adult rats exhibit a significant rapid eye movement (REM) sleep rebound. In this study, we examined this phenomenon in aged animals. We found that aged rats subjected to an IS did not show a sleep rebound after the restraint, in contrast to younger animals. Plasma corticosterone and corticotrophin (ACTH(1)(-)(39)) levels were, however, similar in aged and adult rats. The corticotrophin-like intermediate lobe peptide (CLIP or ACTH(18)(-)(39)) system of the arcuate nucleus, suggested to be involved in REM sleep genesis by way of pontine projections (HP: the hypothalamo-pontine axis), was also not different between aged and young rats. The lack of REM sleep rebound observed in aged animals is thus independent of the HPA (hypothalamo-pituitary-adrenal) and HP axe activities. The causal impairments might reside in REM sleep executive structures of the dorsal pontine tegmentum.

Topics: Adrenocorticotropic Hormone; Aging; Animals; Corticosterone; Corticotropin-Like Intermediate Lobe Peptide; Disease Models, Animal; Hypothalamo-Hypophyseal System; Immobilization; Neural Pathways; Rats; Rats, Wistar; Restraint, Physical; Sleep Wake Disorders; Sleep, REM; Stress, Psychological