Decreased benzodiazepine receptor binding in epileptic El mice: a quantitative autoradiographic study.

Benzodiazepine receptors and subtypes were examined in El mice and normal ddY mice with a quantitative autoradiographic technique. Specific [3H]flunitrazepam binding in stimulated El mice, which had experienced repeated convulsions, was significantly lower in the cortex and hippocampus than in ddY mice and unstimulated El mice. In the amygdala, specific [3H]flunitrazepam binding in stimulated El mice was lower than in ddY mice. There was a tendency for the [3H]flunitrazepam binding in these regions in unstimulated El mice to be intermediate between that in stimulated El mice and that in ddY mice, but there was no significant difference between unstimulated El mice and ddY mice. [3H]Flunitrazepam binding displaced by CL218,872 was significantly lower in the cortex of stimulated El mice than in that of the other two groups, and in the hippocampus of stimulated than of unstimulated El mice. These data suggest that the decrease in [3H]flunitrazepam binding in stimulated El mice may be due mainly to that of type 1 receptor and may be the result of repeated convulsions.