REGIONAL EXCITATORY AND INHIBITORY AMINO-ACID-CONCENTRATIONS IN PENTYLENETETRAZOL KINDLING AND KINDLED RAT-BRAIN

We determined regional concentrations of excitatory and inhibitory ami no acids in pentylenetetrazol (PTZ) kindling and kindled rat brains in order to investigate the mechanisms responsible for the PTZ kindling process and kindled state. Compared with control rats, PTZ kindling ra ts had significantly higher concentrations of aspartate in the striatu m and the temporal cortex 24 h after the 14th injection of PTZ. Glutam ate and GABA concentrations were also significantly higher in the brai nstem of PTZ kindling rats 24 h after the 14th injection of PTZ. These findings suggest that the striatum and temporal cortex may participat e in a pathway for propagation of the PTZ kindling process, and that t he brainstem may be a primary site of PTZ kindling epileptogenesis or a part of the pathways for propagation. On the other hand, the concent rations of amino acids in PTZ kindled rats and controls did not differ 4 weeks after the 14th injection. This suggests that the alterations we detected in amino acid metabolism are not related to retention of t he PTZ kindled state, and that some other mechanism for it must exist. (C) 1997 Elsevier Science B.V.