EFFECTS OF SELECTIVE SEROTONERGIC LIGANDS ON POSTHYPOXIC AUDIOGENIC MYOCLONUS

Male Sprague-Dawley rats underwent cardiac arrest and resuscitation, s ubsequently exhibiting posthypoxic myoclonus. The audiogenic posthypox ic myoclonus in these animals could be attenuated with the following d rugs: 5-hydroxytryptophan (5-HTP, serotonin [5-HT] precursor), N-(3-tr ifluoromethylphenyl)piperazine hydrochloride (TFMPP, 5-HT1B/1C/2 agoni st), (+/-)-2,5-dimethoxy-4-iodoamphetamine hydrobromide (DOI, 5-HT2 ag onist), and 1-(m-chlorophenyl)-biguanide hydrochloride (m-CPBG, 5-HT3 agonist). In contrast, the following drugs were ineffective: (+/-)-8-h ydroxy-dipropylaminotetralin hydrobromide (8-OH-DPAT, 5-HT1A agonist), buspirone hydrochloride (5-HT1A agonist), 4(4-methyl-1-piperazinyl)py rrolo[1,2-a]quinoxaline maleate (CGS 12066B, 5-HT1B agonist), ketanser in tartrate (5-HT2 antagonist), methysergide maleate (5-HT2 antagonist ), fluoxetine (5-HT uptake blocker), and saline (vehicle). The data su ggest that enhancement of serotonergic activity, particularly through 5-HT2 and 5-HT3 receptors, have therapeutic potential for the treatmen t of posthypoxic myoclonus.