Functional [14C]2-deoxyglucose mapping of progressive states of status epilepticus induced by amygdala stimulation in rat

Abstract

Electrical stimulation of rat amygdala induced self-sustained steady-state seizures (status epilepticus (SE] within 60 min. These SE states varied in behavioral severity from mere alteration of motility to frank clonic convulsions. Four distinct behavioral states were observed: immobility, exploration, mastication and clonus. These SE states were associated with [14C]2-deoxyglucose (2-DG) autoradiography anatomic patterns that were correspondingly more extensive and complex. Four distinct 2-DG activation patterns were observed: a restricted pattern involving several discrete limbic nuclei, including amygdala; more extensive patterns involving numerous limbic areas, first unilaterally, then bilaterally; finally the most extensive pattern involving widespread areas of forebrain. These data imply a systematic progression of seizure activity: originating in the amygdala, then spreading to some direct amygdala projection areas, and from there to a restricted network of interconnected ipsilateral limbic nuclei. This restricted network then recruits most of the remaining limbic structures, first ipsilaterally, then contralaterally. Finally, most of the basal ganglia, thalamus and neocortex are recruited.