Neurochemical Control of Circadian Rhythms
Abstract
The central aim of this grant was to identify which of the various neurotransmitters found within the suprachiasmatic nucleus (SCN) are involved in synchronizing circadian rhythms with the day-night cycle. Our approach was to determine which SCN neurotransmitters are both influenced by light and capable of shifting the phase of circadian rhythms. We have investigated the possible role of a (number of neurotransmitters in circadian control (e.g. vasopressin, GABA, neuropeptide Y). However, out primary focus has been on the circadian functions of vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI) and gastrin releasing peptide (GRP). As the result our work on VIP, PHI and GRP we have developed a working hypothesis of the neurochemical mechanisms underlying the synchronization of circadian rhythms with the day-night cycle. The hypothesis, called the ratio hypothesis, states that light communicated to the SCN via afferent pathways sets the ratio of VIP/PHI to GRP available for release from SCN neurons by altering the cellular levels of VIP/PHI mRNA and/or GRP mRNA, and that the ratio of VIP/PHI to GRP released from SCN neurons in response to light determines how the circadian clock is reset by light. Peptides, hypothalamus, colocalization, light, gene expression.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 02, 1992
- Accession Number
- ADA255054
Entities
People
- H. E. Albers
Organizations
- Georgia State University