Kainate and quisqualate receptor autoradiography in rat brain after angular bundle kindling.

Published

Journal Article

The kainate and quisqualate types of excitatory amino acid receptor were visualized autoradiographically in brain sections from rats kindled by stimulating the angular bundle. Kainate receptors were labeled with [3H]kainate and quisqualate receptors with L-[3H]glutamate. When assayed one day after the last evoked seizure, kainate receptor binding had declined by 24-29% in stratum lucidum of hippocampal area CA3 and by 12-14% in the inner third of the dentate molecular layer, but was unchanged in the neocortex and basolateral amygdala. Saturation binding curves revealed that, under the conditions of these experiments, [3H]kainate labeled a single class of binding sites with a KD of 33-36 nM. In stratum lucidum of area CA3, kindling reduced the density of kainate receptors without altering their affinity for kainate. At the same time, quisqualate receptor binding had declined by 20-35% in many layers of the hippocampal formation and neocortex, but remained unchanged in the basolateral amygdala. Repeated stimulation or repeated seizures were required to produce these effects, since both kainate and quisqualate receptor binding were unchanged one day after a single afterdischarge. These receptor changes largely or completely reversed during a 28-day period without further stimulation. Thus maintenance of the kindled state probably cannot be explained by a long-lasting change in the expression of kainate or quisqualate receptors. The transient, regionally-selective down-regulation of these receptors may represent a compensatory response of forebrain neurons to repeated stimulation or seizures.

Full Text

Duke Authors

Cited Authors

  • Okazaki, MM; McNamara, JO; Nadler, JV

Published Date

  • 1990

Published In

Volume / Issue

  • 37 / 1

Start / End Page

  • 135 - 142

PubMed ID

  • 2173811

Pubmed Central ID

  • 2173811

International Standard Serial Number (ISSN)

  • 0306-4522

Digital Object Identifier (DOI)

  • 10.1016/0306-4522(90)90198-d

Language

  • eng

Conference Location

  • United States