Abstracts

RATIONALE: The objective was to compare norepinephrine (NE) concentrations in locus ceruleus complex (LC) and amygdala before during and after amygdala kindling as a function of gender and seizure susceptibility.
METHODS: Subjects were 16 preadolescent cats ([lt] 1 year, 8 male & 8 female). NE concentrations (5 min microdialysis samples at 2 [mu] l/min infusion rate) were obtained over 2 consecutive days (6-8h polygraphic recordings) before and one month after kindling as well as during a [dsquote]one day[dsquote] kindling paradigm involving one per min electrical stimulations evoking either focal afterdischarge (FAD) or generalized AD (GAD) for 1 h each. See Fig 1.
RESULTS: When compared to females, males had lower NE concentrations (fmol/sample) at both collection sites before and 1 month after kindling but higher NE concentrations during FAD and GAD (Fig 1). The most salient correlate of gender specific findings during kindling was seizure severity, indexed by longer duration of FAD and GAD (sec) as well as longer duration or increased number of behavioral seizure manifestations (not shown). One month after kindling, females showed more extreme fluctuation than males in NE concentrations and spontaneous seizure activity (shown). However, preliminary findings suggested that males continued to show higher and more persistent susceptibility to evoked and spontaneous seizures after dialysis was discontinued (not shown).
CONCLUSIONS: Lower NE concentrations are more likely to predict increased susceptibility to onset and persistence of a severe seizure disorder in young males than in young females.[figure1]
[Supported by: Department of Veterans Affairs]