The NO hypothesis: Possible effects of a short-lived, rapidly diffusible signal in the development and function of the nervous system
- Neurosciences Institute of the Neurosciences Research Program, New York, NY (USA)
Several observations suggest that the Ca{sup 2+}-dependent postsynaptic release of nitric oxide (NO) may be important in the formation and function of the vertebrate nervous system. The authors explore here the hypothesis that the release of NO and its subsequent diffusion may be critically related to three aspects of nervous system function: (i) synaptic plasticity and long-term potentiation in certain regions of the adult nervous system, (ii) the control of cerebral blood flow in such regions, and (iii) the establishment and activity-dependent refinement of axonal projections during the later stages of development. In this paper, they detail and analyze the basic assumptions underlying this NO hypothesis and describe a computer simulation of a minimal version of the hypothesis. In the simulation, a 3-dimensional volume of neuropil is presented with patterned afferent input; NO is produced, diffuses, and is destroyed; and synaptic strengths are determined by a set of synaptic rules based on the correlation of synaptic depolarization and NO levels. According to the hypothesis, voltage-dependent postsynaptic release of this rapidly diffusing substance links the activities of neurons in a local volume of tissue, regardless of whether the neurons are directly connected by synapses. This property is demonstrated in the simulation, and it is this property this is exploited in the hypothesis to account for certain aspects of long-term potentiation and activity-dependent sharpening of axonal arbors.
- OSTI ID:
- 5447720
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America; (United States), Vol. 87:9; ISSN 0027-8424
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
NERVOUS SYSTEM
ONTOGENESIS
NITRIC OXIDE
BIOLOGICAL EFFECTS
ADULTS
BLOOD FLOW
CEREBRUM
DIFFUSION
PHYSIOLOGY
AGE GROUPS
BODY
BRAIN
CENTRAL NERVOUS SYSTEM
CHALCOGENIDES
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANS
OXIDES
OXYGEN COMPOUNDS
560300* - Chemicals Metabolism & Toxicology