Effects of pentylenetetrazol-induced kindling on mature and immature rat behavior, emotional learning and levels of nitric oxide in brain and serum

Abstract

Objectives: This aim of this study was to investigate emotional memory-learning and behavioral functions, as well as the relationship between these functions and the nitric oxide (NO) level in the serum and brain of mature and immature rats following pentylenetetrazol (PTZ)-induced kindling. Methods: A total of 36 male Wistar albino rats were included in the study. Kindling was induced by repeated injections of a subconvulsive dose of PTZ (30 mg/kg) on alternate days until kindling development. The rats were tested using an elevated T-maze and an open-field test after PTZ kindling. Brain and serum NO levels were assessed. Results: Although both mature and immature rats were susceptible to PTZ-induced seizures, the mature rats had seizures of longer duration than the immature rats, with the exception of infants. There was no demonstrated effect of PTZ-kindling on emotional memory and learning functions in any of the rats. Anxiety levels were low in the mature-kindled rats but were high in the immature-kindled rats. NO levels in the brain were elevated and anxiety reactions were below normal in the mature rats. In immature rats, however, NO levels were normal, but anxiety reactions were elevated. Conclusion: Seizure susceptibility, emotional responses, and the relationship between these factors and brain NO level after PTZ-kindling differed in rats based on brain maturity status.