the effect of quinpirol and sulpiride on the brain activity waves in conscious and aneasthetized rat

brain's waves are produced by spontaneous activity of neurons. these waves are changed by neurotransmitters in the central nervous system (cns). concentration of these neurotransmitters can be changed by various drugs and total power of brain waves also increase or decrease by these drugs. in this research effect of quinpirol and sulpiride on the brain waves was investigated. male wistar rats (weight 190-230) were aneasthetized with thiopental and two holes were made into the frontal and occipital area and two ag/agcl electrodes were fixed into these holes. one week after recovery, two electrodes were connected to the physiograph and the results were analyzed before and after intraperitoneal and intracerebroventricular (icv) injection of drugs by pc computer. our results showed that intraperitoneal administration (5 mg/kg) of diazepam reduced the depth of anesthesia. conversely, intracerebroventricular injection of sulpiride increased the depth of anesthesia which was manifested by an increase in relative power of delta waves and reduction of relative power of alpha waves. this drug had a biphasic effect on eeg, at high doses in increased the depth of aneasthesia and total sleep. wehteas depth of anesthesia was decreased at low dose. simutanuos administration of sulpiride and quinpirole produced an effect on eeg similar to diazepam. as a result, biphasic effect of d2 agonist and antagonist drugs on brain waves are due to nonspecific action of these drugs on these receptors and this effect may be produced by other mechanisms