Audiogenic seizures and brain extracts: enhancement by extracts from C57BL/6J mice subjected to audiogenic priming

Abstract

Donor C57BL/6J mice were given audiogenic priming (AP) by exposure to noise at 16 days of age (To) and sacrificed at intervals from 1 hr to 18 days therafter. Brains from AP and littermate non-AP mice were extracted in 1 M acetic acid, and passed through a filter with a nominal mol. wt. cutoff of 10,000 daltons. The filtrates were lyophilized and resuspended in H2O (0.1 ml/brain). Recipient C57BL/6J mice were also exposed to 30 sec of 127 +/- 2 dBA at 16 days of age, and injected IP with one brain-equivalent of extracts from either AP or non-AP donors immediately therafter. All recipients were tested for convulsability at 18 days of age. There were no differences in audiogenic convulsion rates between groups given AP or non-AP extracts from donors sacrificed 1 to 4 hr after To. Recipient convulsion rates were higher in AP relative to non-AP extract-injected mice whenAP donors were sacrificed 1 to 18 days after To. The extract taken from donors 1 day after To appears more potent than extract taken either before or later.