Pharmacology of the Brain: The Hippocampus, Learning and Seizures

Effect of Seizures and Anticonvulsant Agents on Hippocampal RNA Concentration

“…It is interesting that they did so in spite of being unable to actually prevent seizure discharges and of having diverse mechanisms of anti epileptic action (6,10,17). In the hippocampus, for example, where all of them have been shown to raise seizure threshold (6,9,12), diphenylhydantoin and cannabidiol apparently act by blocking K+ release (9,12), whereas phénobarbital and trimethadione do not affect K+ release and presumably act somewhere further on in the chain of events triggered by high K+ (14).…”

“…RNA concentration was read by measuring absorbance at 260 nm in a spectrophotome ter (7,9,13,15,16). Values were expressed in all cases as means ± standard errors, and statistical analysis was performed by an analysis of variance followed by a 't' test when appropriate.…”

“…Since the first region of the brain to become involved in diverse types of generalized convulsions is the hippocampus (1,4,9,17) which is also the one with the lowest seizure threshold (4,5), we decided to study the effect of convulsant and anticonvulsant agents on hippocampal RNA. Previous studies from this laboratory had shown that moder ate afferent stimulation (15) or localized hippocampal perfusion with moderate ly high K+ concentrations (7) caused an increase of hippocampal RNA levels, whereas more rapid stimulation (15) or too high K+ concentrations in the perfu sion fluid (7) had an opposite effect.…”