Kindling: some old and some new.

A brief review of kindling is provided, which highlights some important points of historical interest often overlooked by researchers. These points include the fact that the original rating scale of convulsive seizures presented by Racine 'EEG Clin. Neurophysiol 32 (1972) 281'. was based on amygdala kindling, and may not be applicable to kindling from other sites. The functional anatomy of these convulsive seizures was similarly addressed. Also emphasized was the observation that kindling results ultimately in spontaneous seizures, seemingly identical to those seen in models of status epilepticus (SE), and can provide a unique perspective on those seizures because of its controlled natural history and minimal brain damage. Much of the recent work described here focused on genetic susceptibility versus resistance to kindling, as witnessed by the Fast and Slow kindling rat strains. The results of those studies indicated substantial strain differences in GABAergic function in different limbic structures associated with GABA(A) subunit expression, spontaneous miniature inhibitory postsynaptic currents (mIPCs) and behavioral comorbidities. We concluded the review with our recent attempt to discover consistent and unique gene profile differences associated with the different seizure predispositions of the Fast and Slow kindling rat strains.