NMDA and non-NMDA sensitive [L-3H]glutamate receptor binding in the brain of the Naples high- and low-excitability rats: an autoradiographic study.
The Naples high-excitability (NHE) and low-excitability (NLE) rat lines, selectively bred for high and low activity in a Làt maze, respectively, are used as an animal model in the study of hippocampal functions. The aim of this study was to investigate the anatomical distribution of N-methyl-D-aspartate (NMDA) and non-NMDA sensitive [3H]glutamate receptor binding by quantitative autoradiography in the brain of the NHE and NLE rats with a randomly bred line (NRB) as controls. Twenty-micron-thick cryostat sagittal sections were incubated at 4 degrees C with 150 nM [L-3H]glutamate alone or in the presence of 100 microM NMDA or 2.5 microM quisqualate (QA). Non-specific binding was determined in the presence of 1 mM of non-labeled glutamate. The sections were exposed to tritium-sensitive films for 3 weeks at 4 degrees C. Quantitative analysis revealed: (1) higher levels of total binding in NHE than in NRB and NLE rats in all areas but the cerebellum; (2) fewer binding sites for both NMDA and QA receptors and larger binding sites for QA receptors in the hippocampus of NLE and NHE rats, respectively; (3) a positive correlation between total binding sites and activity level in a Làt maze in all areas, except the cerebellar molecular layer with NLE < NHE, which was due to differential contribution from NMDA and non-NMDA types. Thus, the brain of the NHE rats shows an imbalance between NMDA and non-NMDA sensitive [L-3H]glutamate receptors.
Sadile
A G
AG
Department of Human Physiology F. Bottazzi, Second University of Naples (SUN), Italy. sadile@ds.unina.it
Pellicano
M P
MP
Sagvolden
T
T
Sergeant
J A
JA
D000818:Animals; D001289:Attention Deficit Disorder with Hyperactivity / Q000523:psychology; D001345:Autoradiography; D001921:Brain / Q000033:anatomy & histology*; D001923:Brain Chemistry / Q000235:genetics / Q000502:physiology*; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000235:genetics / Q000502:physiology*; D016202:N-Methylaspartate / Q000494:pharmacology; D016318:Quisqualic Acid / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017470:Receptors, Glutamate / Q000235:genetics / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000502:physiology*; D013045:Species Specificity
D018690:Excitatory Amino Acid Agonists; D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D016202:N-Methylaspartate; D016318:Quisqualic Acid