Differential effects of aging on NMDA receptors in the intermediate versus the dorsal hippocampus.
There are discrepancies in the literature about the effects of aging on NMDA receptor expression in the hippocampus. The present study was designed to determine whether there are regional differences in how NMDA receptors are affected by aging. Brains from male C57BL/6 mice from three different age groups (3, 10, and 30 months of age) were sectioned coronally through the dorsal hippocampus and horizontally through the intermediate hippocampus. Sections were processed and analyzed for [3H]glutamate binding to NMDA receptors using receptor autoradiography and for mRNA for the zeta1 (NR1), epsilon1 (NR2A), and epsilon2 (NR2B) subunits of the NMDA receptor using in situ hybridization. There were more significant effects of aging within the intermediate hippocampus in NMDA-displaceable [3H]glutamate binding and epsilon2 mRNA densities than were seen in the dorsal hippocampus. There was no significant effect of age on densities of either the zeta1 or epsilon1 subunit mRNA. These results suggest that the aging process affects NMDA receptors more in the intermediate hippocampus than the dorsal.
Magnusson
Kathy Ruth
KR
Department of Biomedical Sciences, College of Veterinary Medicine and Biomedical Sciences, Program in Molecular, Cellular, and Integrative Neurosciences, Colorado State University, Fort Collins, CO 80523, USA. kmagnuss@uidaho.edu
Kresge
Darra
D
Supon
Julie
J
D000367:Age Factors; D000375:Aging / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D001345:Autoradiography / Q000379:methods; D005786:Gene Expression Regulation / Q000502:physiology*; D018698:Glutamic Acid / Q000493:pharmacokinetics; D006624:Hippocampus / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism*; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D014316:Tritium / Q000493:pharmacokinetics
D021122:Protein Subunits; D016194:Receptors, N-Methyl-D-Aspartate; D014316:Tritium; D018698:Glutamic Acid