a neurochemical and electrophysiological study on the combined effects of caffeine and nicotine in the cortex of rats

Introduction: caffeine and nicotine are the most widely consumed psychostimulantsworldwide. although the effects of each drug alone on the central nervous system have beenstudied extensively, the literature on the neurochemical and electrophysiological effects of theircombined treatments is scarce. the present study investigated the cortical electrophysiologicaland neurochemical alterations induced by acute administration of caffeine and nicotine in rats.methods: the rats received caffeine and nicotine at a 1-hour interval between the twotreatments.results: caffeine and nicotine administration resulted in a significant decrease in theconcentrations of cortical amino acid neurotransmitters, namely glutamate, aspartate, glycine,and taurine, while γ-aminobutyric acid (gaba) significantly increased. increased corticallipid peroxidation and reduced glutathione and nitric oxide levels and acetylcholinesteraseand na⁺/k⁺-atpase activities were also observed. the electroencephalogram (eeg) showedan increase in delta frequency power band, whereas theta, beta-1, and beta-2 decreased aftercaffeine and nicotine treatment.conclusion: these findings suggest that caffeine and nicotine adversely exacerbate theirstimulant effects manifested by the eeg changes mediated by increasing cholinergictransmission and disturbing the balance between the excitatory and inhibitory amino acidsleading to oxidative stress.