Adenosine modulation of amygdala kindling.

To test the hypothesis that kindling is restrained by the inhibitory neuromodulator, adenosine, the adenosine uptake blocker, papaverine, or the adenosine antagonist, aminophylline, were injected systemically into rats 20 min before each daily electrical stimulation of the amygdala. The effects on amygdala-triggered seizures of papaverine, adenosine, 2-chloroadenosine, and the adenosine antagonists, isobutylmethylxanthine and caffeine, were also investigated at seizure threshold. Papaverine inhibited kindling, whereas aminophylline accelerated kindling. The adenosine agonists had anticonvulsant effects on seizures, and the antagonists had proconvulsant effects which involved, primarily, the lengthening of afterdischarge duration. Aminophylline injected repeatedly, in the absence of electrical stimulation, induced seizures. These results support the hypothesis that adenosine can modulate kindling and affect the seizure process.