Effects of adenosine receptor agonists and antagonists on pentylenetetrazole-induced amnesia

The effect of adenosine agents on amnesia induced by pentylenetetrazole was examined in mice. Post-training administration of pentylenetetrazole (50 a nd 60 mg/kg) disrupted 24-h retention of a single-trial passive avoidance t ask. The adenosine receptor antagonists, theophylline (2.5-25 mg/kg) and 8- phenyltheophylline (0.5-2 mg/kg), administered 30 min before and just after training at doses which did not affect retention, reduced the amnestic eff ect of pentylenetetrazole in a dose-dependent manner. Post-training adminis tration of the adenosine A(1) receptor agonists, N-6-cyclohexyladenosine (C HA, 0.1 and 0.5 mg/kg) and N-6-phenylisopropyladenosine (R-PIA, 0.03 and 0. 1 mg/kg), but not the adenosine A, receptor agonist, 5'-N-ethylcarboxamidoa denosine (NECA, 0.01 and 0.001 mg/kg), impaired retention. Nonamnestic dose s of CHA and R-PIA potentiated the disruption induced by a lower dose of pe ntylenetetrazole (40 mg/kg). NECA did not induce any response in this respe ct. It is suggested that an adenosine A(1) receptor mechanism is involved i n amnesia induced by pentylenetetrazole. (C) 2001 Published by Elsevier Sci ence B.V.