Effects of purine analogues on spontaneous alternation in mice

The Y-maze was used to examine the effects of purines acting at A(1) and A(2) adenosine receptors upon spontaneous alternation, a model of working memory, in mice. In support of previous work, scopolamine produced a loss of spontaneous alternation behaviour to the 0.5 chance level. The A(1) receptor selective agonist N6-cyclopentyladenosine (CPA) did not change spontaneous alternation behaviour alone, but it prevented the decrease of spontaneous alternation scores produced by scopolamine. The A(1) receptor selective antagonist 1,3-dipropyl-8-cyclopentylxanthine (CPX) blocked the effect of CPA in combination with scopolamine but had no effect alone. The A(1) receptor selective agonist (N6-[2-(3,5-dimethoxyphenyl)-2-(2-methylphenyl)ethyl]adenosine (DPMA), and the A(2) receptor selective antagonist 3,7-dimethyl-1-propargylxanthine (DMPX) had no effect of alternation behaviour alone and did not modify the effect of scopolamine The results indicate the ability of A(1) but not A(2) receptor activation to modify working memory deficits induced by scopolamine, but suggest that endogenous adenosine does not normally participate in working memory processes.