Blockade of ethanol induced conditioned taste aversion by 3-amino-1,2,4-triazole: evidence for catalase mediated synthesis of acetaldehyde in rat brain.

This investigation seeks to present evidence for the oxidation of ethanol in the brain via the peroxidatic activity of catalase and simultaneously provide evidence for the role of central acetaldehyde (ACH) in the mediation of an ethanol-induced conditioned taste aversion (CTA). Ethanol is capable of inducing a conditioned taste aversion. Pretreatment with the catalase inhibitor, 3-amino-1,2,4-triazole (AT), shows an attenuation of this ethanol-induced CTA. Animals receiving ethanol injections showed a CTA to a novel solution paired with a drug administration, while ethanol injected animals pretreated with AT did not show a CTA to ethanol administration. This effect of AT appears to be specific to the effects of ethanol as CTA's to morphine and lithium chloride were not affected by AT pretreatment. Peripheral levels of ethanol were the same in all animals regardless of pretreatment indicating that AT had no effect on peripheral levels of ethanol. These data increase support for the notion that acetaldehyde is produced directly in the brain and that it may be the agent mediating some of the psychopharmacological properties of ethanol.