Effects of neuropeptide Y on peniciline induced experimental epilepsy

ABSTRACTEpilepsy is one of the frequently observed central nervous system disorder. Thisdisorder is charachterized by partial or generalize uncontrolled activation of central nervoussystem. Pathologicaly, simultaneous and noncontrolled discharge of neurons is same in allepilepsy types and the mechanism that triggers is not known yet. Balance between excitationand inhibition during epileptic seizures favours to exitation side and various neurotransmittersubstances are secreted. Some of these secreted neurotransmitters have an increasing effect onexitation, while some have decreasing effect. One of the substance that decreases excitation,having various metabolic functions, being endogen anticonvulsant and mostly found in centralnervous system is neuropeptid Y (NPY). NPY was found by Tatemoto and Mutt in 1982.NPY has thirty-six amino acids and five functional receptors. It is secreted and stored withGABA in GABA-ergic interneurons. It was explained that calcium ions has an important rolein epileptic seizures. Intercellular intake of calcium results in secretion of excitatorneurotransmitters. Some in vitro studies show that; flow of calcium in presynaptic terminals(Greber et all., 1994) and glutamate secretion in hippocampal region is supressed by NPY. Inthis study effect of NPY on penisilin model epilepsy which is one of the basic partial epilepticmodel was explored. Our aim was to explore whether NPY has an anti-epileptic effect onepilepsy just same as in other epileptic models and its effective mechanism. For thisexperiment male, Wistar, albino, having weight of 230-270 g rats were used. Subjects wereseperated into two groups; while the second group was accepted as an control group, firstgroup was used for NPY experiments. Electrocorticographic brain bioelectrical potentials(ECoG) were recorded digitally by PowerLab/8SP data aquising system. Results wereanalysed by independent t test. Decrease in both amplitude and frequency measured indifferent times, analysed was found statistically significant. Decrease in amplitude was muchmore than compared to control group in NPY group after the 40-45. minute measurement.Likewise, decrease on spike-wave activities in NPY group after the 50-55. minutemeasurement was found statistically significant (P<0.05). As a result; just as in other epilepticmodels, NPY inhibits epileptic seizures in penisilin model epilepsy.Key words: Neuropeptid Y, epilepsy, electrocorticography (ECoG), GABA, glutamate,anticonvulsant effect