Chemical kindling induced by pentylenetetrazol changes cholecystokinin mRNA and peptide levels in rat frontal cortex

Kindling model is useful to study the mechanism of learning and memory. Cholecystokinin (CCK) mRNA and CCK-like immunoreactivity (CCK-LI) levels in the hippocampus and frontal cortex of chemically kindled rats were determined at different time points. In the frontal cortex, chronic treatment with pentylenetetrazol (PTZ) (40 mg/kg per day for 8 days) increased CCK mRNA level at 7 days, and decreased CCK-LI level at 2 and 7 days after the last injection. However, neither CCK mRNA nor CCK-LI levels in the hippocampus changed. These results suggest that PTZ-induced kindling increases CCK mRNA expression and CCK-LI release in the frontal cortex.