BEHAVIORAL-EFFECTS OF THE PUTATIVE ANXIOLYTIC (+ 1-(2,5-DIMETHOXY-4-ETHYLTHIOPHENYL)-2-AMINOPROPANE (ALEPH-2) IN RATS AND MICE/

Behavioral effects of the phenethylamine derivative 1-(2,5-dimethoxy-4 -ethylthiophenyl)-2-aminopropane (ALEPH-2) were studied in mice and ra ts. Murine locomotor activity, measured with a photocell actometer, wa s markedly depressed following IF injection of 2 and 6 mg/kg of the dr ug. The same doses of the drug also decreased frequency and duration o f head dipping and the number of rearings in the hole board apparatus. In the murine elevated plus maze 2 and 6 mg/kg of ALEPH-2 increased t he percentage of both open arm entries and time. The total number of e ntries into the enclosed arms was not significantly affected by the dr ug. In the rat, 2-12 mg/kg ALEPH-2, IF, decreased photobeam counts in the actometer in a dose-dependent fashion. Both 2 and 4 mg/kg of the d rug increased the percentage of open arm entries, but only the highest dose significantly increased the percentage of time spent on the open arms. The dose of 4 mg/kg ALEPH-2 also significantly decreased the to tal number of enclosed arm entries. Finally, in a recently developed m odel of anxiety and memory, the elevated T-maze, the doses of 2 and 4 mg/kg ALEPH-2 did not change inhibitory avoidance of the open arms. Ne vertheless, the highest dose had an amnestic effect on this task, repe ated 72 h later in the absence of drug. In addition, this dose signifi cantly increased the latency to escape from the open arms and had an a mnestic effect measured 72 h later. Overall, these results indicate th at ALEPH-2 possesses anxiolytic, amnestic as well as sedative and/or m otor depressant actions.