POSTTRIAL ETHERIZATION HAS BEEN SHOWN TO HAVE A FACILITATIVE EFFECT UPON RETENTION IN MICE OF STRAIN DBA/2J, BUT NO EFFECT UPON MICE OF STRAIN C57BL/6J. PRETREATMENT OF MICE OF STRAIN C57BL/6J WITH RESERPINE (A DRUG WHICH REDUCES BRAIN LEVELS OF NOREPINEPHRINE, DOPAMINE, AND GAMMA-AMINOBUTYRIC ACID) RESULTED IN APPEARANCE OF THE ETHER FACILITATION EFFECT IN THIS HITHERTO UNAFFECTED STRAIN. THIS RESULT SUGGESTS THAT ETHER FACILITATION IN STRAIN DBA/2J MAY BE DUE TO STIMULATION BY ETHER OF INCREASED RELEASE OF BRAIN NOREPINEPHRINE, DOPAMINE, OR GAMMA-AMINOBUTYRIC ACID. (15 REF.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)