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Laminar distribution of NMDA receptors in cat and monkey visual cortex visualized by [ 3 H]‐MK‐801 binding
Author(s) -
Rosier A. M.,
Arckens L.,
Orban G. A.,
Vandesande F.
Publication year - 1993
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.903350307
Subject(s) - nmda receptor , biology , glutamate receptor , neuroscience , glutamatergic , visual cortex , receptor , cortex (anatomy) , excitatory postsynaptic potential , long term depression , biophysics , biochemistry , ampa receptor , inhibitory postsynaptic potential
Glutamate is the major excitatory neurotransmitter of the mammalian central nervous system. Two major classes of glutamate receptors have been reported. The actions of glutamate on its N ‐methyl‐D‐aspartate (NMDA)‐type receptor may underlie developmental and adult plasticity as well as neurotoxicity. The NMDA‐type of glutamate receptor in cat and monkey visual cortex was visualized by means of in vitro receptor autoradiography with the noncompetitive NMDA‐receptor antagonist [ 3 H]‐MK‐801. The kinetics, performed on tissue sections, revealed an apparently single, saturable site with an approximate dissociation constant (KD) of 18.5 nM in cat and 15.9 nM in monkey visual cortex. Autoradiography, performed on frontal sections of cat and monkey visual cortex, revealed a heterogeneous laminar distribution of NMDA receptors. Cat areas 17,18,19, and the lateral suprasylvian areas exhibited a similar NMDA‐receptor distribution. In these areas, NMDA receptors were most prominent in layer II and the upper part of layer III. In monkey striate cortex, NMDA receptors were primarily concentrated in layers II, upper III, IVc, V, and VI. In monkey secondary visual cortex, [ 3 H]‐MK‐801 labeling was most prominent in layers II, V, and VI; whereas in the temporal visual areas included in this study layer II displayed the heaviest receptor labeling. In neither cat nor monkey could we observe significant differences in NMDA‐receptor distribution between different retinotopic subdivisions within a single visual area. Neither did we detect any periodic changes in NMDA‐receptor distribution that would correspond to the compartments defined by cytochrome‐oxidase in monkey V1 and V2. © 1993 Wiley‐Liss, Inc.