Accession Number:

ADA379224

Title:

Membrane Properties and Neural Circuits of the Suprachiasmatic Nucleus.

Descriptive Note:

Final Technical rept. 1 Jul 96-30 Jun 99

Corporate Author:

COLORADO STATE UNIV FORT COLLINS DEPT OF ANATOMY AND NEUROBIOLOGY

Personal Author(s):

• Dudek, Edward F.
• Rash, John E.
• Yasumura, Thomas
• Strecker, G. J.
• Smith, Bret N.

Report Date:

1999-06-30

Pagination or Media Count:

7.0

Abstract:

The goal of these studies was to examine local synaptic circuits in the suprachiasmatic nucleus and the effect of GABA on suprachiasmatic nucleus neurons. Electrophysiological evidence was provided to support the hypothesis that suprachiasmatic nucleus neurons are interconnected through a system of GABA- mediated local circuits. Previous studies had suggested that GABA was excitatory during subjective day, but our lab and two others corroborated and extended previous findings indicating that GABA is inhibitory during both subjective day and night. Other experiments showed that zinc and benzodiazepines modulate GABA-mediated inhibition of suprachiasmatic nucleus neurons. In particular, benzodiazepines augment the effect of GABA on these inhibitory circuits. These experiments have provided fundamental information on GABA-mediated local circuits in the suprachiasmatic nucleus, which would be expected to be a fundamental part of the circadian timing system in mammals.

Descriptors:

• *CIRCADIAN RHYTHMS
• *MAMMALS
• *AUGMENTATION
• *NEUROTRANSMITTERS
• FIBER OPTICS
• MEMBRANES(BIOLOGY)
• NEURAL NETS
• ZINC
• NIGHT
• CIRCUITS
• HYPOTHESES
• INHIBITION
• SYNAPSE
• ELECTROPHYSIOLOGY

Subject Categories:

• Anatomy and Physiology
• Medicine and Medical Research

Distribution Statement:

APPROVED FOR PUBLIC RELEASE