tokens: In rodents , the effect of the beta - carboline derivative isopropyl - 6 - benzyloxy - 4 - methoxymethyl - beta - carboline - 3 - carboxylate ( abecarrnil ) , a new ligand for benzodiazepine receptors possessing anxiolytic and anticonvulsant properties , was evaluated on the function of central gamma - aminobutyric acid ( GABA ) A receptor complex , both in vitro and in vivo .