Resetting the biological clock: mediation of nocturnal circadian shifts by glutamate and NO
| Autor: | E. T. Weber, Jian M. Ding, Michael A. Rea, Lia E. Faiman, Dong Chen, Martha U. Gillette |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
medicine.medical_specialty
N-Methylaspartate Light Period (gene) Glutamic Acid Endogeny Biology In Vitro Techniques Arginine Nitric Oxide Receptors N-Methyl-D-Aspartate Retina Biological Clocks Internal medicine medicine Animals Circadian rhythm Neurons Afferent Multidisciplinary Suprachiasmatic nucleus Glutamate receptor Circadian Rhythm Rats Endocrinology NG-Nitroarginine Methyl Ester nervous system Light effects on circadian rhythm NMDA receptor Suprachiasmatic Nucleus sense organs Amino Acid Oxidoreductases Nitric Oxide Synthase hormones hormone substitutes and hormone antagonists Retinohypothalamic tract Signal Transduction |
| Zdroj: | Science (New York, N.Y.). 266(5191) |
| ISSN: | 0036-8075 |
| Popis: | Circadian rhythms of mammals are timed by an endogenous clock with a period of about 24 hours located in the suprachiasmatic nucleus (SCN) of the hypothalamus. Light synchronizes this clock to the external environment by daily adjustments in the phase of the circadian oscillation. The mechanism has been thought to involve the release of excitatory amino acids from retinal afferents to the SCN. Brief treatment of rat SCN in vitro with glutamate (Glu), N-methyl-D-aspartate (NMDA), or nitric oxide (NO) generators produced lightlike phase shifts of circadian rhythms. The SCN exhibited calcium-dependent nitric oxide synthase (NOS) activity. Antagonists of NMDA or NOS pathways blocked Glu effects in vitro, and intracerebroventricular injection of a NOS inhibitor in vivo blocked the light-induced resetting of behavioral rhythms. Together, these data indicate that Glu release, NMDA receptor activation, NOS stimulation, and NO production link light activation of the retina to cellular changes within the SCN mediating the phase resetting of the biological clock. |
| Databáze: | OpenAIRE |
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