N-methyl-D-aspartate antagonists suppress the development of frog symmetric monocular optokynetic nystagmus observed after unilateral visual deprivation.
In monocular vision, frogs display a unidirectional optokinetic nystagmus (OKN), reacting only to temporal-nasal (T-N) stimulation. The OKN N-T component is almost absent. However, prolonged monocular visual deprivation by unilateral eyelid suture provoked the appearance of the N-T component. The analysis of search coil recordings showed that the slow phase velocity gain of both T-N and N-T components became similar. Chronic administration of N-methyl-D-aspartate (NMDA) antagonists for the duration of deprivation prevented the appearance of a symmetrical monocular OKN in frogs: following repeated intraperitoneal injections of either MK 801, CGS 19755 or intrapretectal microinjections of 2-amino-5-phosphonovalerate (APV), the N-T component did not appear, and OKN remained asymmetrical. Thus NMDA receptors appear to be involved in the control of the plasticity process which allows monocular OKN of adult lower vertebrates to become symmetrical.
Laboratoire de Neurophysiologie et de Biologie des Comportements, Centre de Neurochimie du C.N.R.S., Strasbourg, France.
B
B
Jardon
N
N
Bonaventure
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D016291:Dizocilpine Maleate / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D008280:Magnetics; D008845:Microinjections; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors*; D009760:Nystagmus, Physiologic / Q000187:drug effects*; D010875:Pipecolic Acids / Q000494:pharmacology; D011893:Rana esculenta; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000502:physiology*; D015349:Vision, Monocular / Q000187:drug effects*
D010875:Pipecolic Acids; D016194:Receptors, N-Methyl-D-Aspartate; C053672:selfotel; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate; D015763:2-Amino-5-phosphonovalerate