2-Chloroadenosine decreases long-term potentiation in the hippocampal CA1 area of the rat

The effect of the adenosine (ADO) analogue 2-chloroadenosine (CADO) on frequency-induced long-term potentiation (LTP) of the responses evoked by stimulation of the Schaffer fibres and recorded in CA1 area was studied in hippocampal slices of the rat. CADO significantly decreased LTP of the population spikes (PS) (EC 50 = 0.28 μM), and LTP of the field excitatory postsynaptic potentials (f.e.p.s.p) (EC 50 = 0.33 μM). These effects were reversed by the ADO receptor antagonist 8-phenyltheophylline (8-PT) (2.5 μM). It is concluded that CADO decreases LTP through activation of a xanthine-sensitive ADO receptor.