NMDA receptors mediate expression of one form of functional plasticity induced by olfactory deprivation.
Unilateral olfactory deprivation for the first 3 postnatal weeks results in an enhancement of granule cell mediated, feedback inhibition of mitral cells in the rat olfactory bulb. Granule cells are excited by mitral cells by both non-NMDA and NMDA receptors. The present report describes the effect of the NMDA antagonist MK-801 (0.75 mg/kg) on the expression of deprivation enhanced inhibition. The results demonstrate that (1) enhancement of lateral olfactory tract paired-pulse inhibition of evoked potentials in deprived bulbs was stimulus intensity dependent, with the greatest difference expressed at highest stimulus intensities; (2) MK-801 reduced inhibition in both undeprived and deprived bulbs in a stimulus intensity dependent manner, with the greatest reduction occurring at highest stimulus intensities; (3) MK-801 eliminated the stimulus intensity effect on inhibition in both groups; and (4) following MK-801, deprived bulbs showed the same or less inhibition than undeprived bulbs.
Wilson
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DA
Department of Zoology, University of Oklahoma, Norman 73019, USA.
D000818:Animals; D000831:Animals, Newborn; D016291:Dizocilpine Maleate / Q000494:pharmacology; D005071:Evoked Potentials / Q000187:drug effects; D008297:Male; D009433:Neural Inhibition / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D009830:Olfactory Bulb / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology*; D012683:Sensory Deprivation / Q000502:physiology*
D016194:Receptors, N-Methyl-D-Aspartate; D016291:Dizocilpine Maleate