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Light-Induced Alterations in Striatal Neurochemical ProfilesMuch of our present knowledge regarding circadian rhythms and biological activity during space flight has been derived from those missions orbiting the Earth. During space missions, astronauts can become exposed to bright/dark cycles that vary considerably from those that entrain the mammalian biological timing system to the 24-hour cycle found on Earth. As a spacecraft orbits the Earth, the duration of the light/dark period experienced becomes a function of the time it takes to circumnavigate the planet which in turn depends upon the altitude of the craft. Orbiting the Earth at an altitude of 200-800 km provides a light/dark cycle lasting between 80 and 140 minutes, whereas a voyage to the moon or even another planet would provide a light condition of constant light. Currently, little is known regarding the effects of altered light/dark cycles on neurochemical levels within the central nervous system (CNS). Many biochemical, physiological and behavioral phenomena are under circadian control, governed primarily by the hypothalamic suprachiasmatic nucleus. As such, these phenomena are subject to influence by the environmental light/dark cycle. Circadian variations in locomotor and behavioral activities have been correlated to both the environmental light/dark cycle and to dopamine (DA) levels within the CNS. It has been postulated by Martin-Iverson et al. that DA's role in the control of motor activity is subject to modulation by circadian rhythms (CR), environmental lighting and excitatory amino acids (EAAs). In addition, DA and EAA receptor regulated pathways are involved in both the photic entrainment of CR and the control of motor activity. The cellular mechanisms by which DA and EAA-receptor ligands execute these functions, is still unclear. In order to help elucidate these mechanisms, we set out to determine the effects of altered environmental light/dark cycles on CNS neurotransmitter levels. In this study, we focused on the striatum, a region of the brain that receives a number of dopaminergic and glutamatergic input and is known to be involved in the modulation of locomotor and behavioral responses.
Document ID
20010000478
Acquisition Source
Headquarters
Document Type
Conference Paper
Authors
Sroufe, Angela E. (Morehouse School of Medicine Atlanta, GA United States)
Whittaker, J. A. (Morehouse School of Medicine Atlanta, GA United States)
Patrickson, J. W. (Morehouse School of Medicine Atlanta, GA United States)
Date Acquired
August 20, 2013
Publication Date
February 1, 1997
Publication Information
Publication: NASA University Research Centers Technical Advances in Education, Aeronautics, Space, Autonomy, Earth and Environment
Volume: 1
Subject Category
Aerospace Medicine
Report/Patent Number
URC97119
Funding Number(s)
CONTRACT_GRANT: NIH-NS34194
CONTRACT_GRANT: NIH-GM08248
OTHER: NCCW-83
CONTRACT_GRANT: NIH-RR03034
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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IDRelationTitle20010000359Collected WorksNASA University Research Centers Technical Advances in Education, Aeronautics, Space, Autonomy, Earth and Environment
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