Adenosine A1R receptor deficiency enhances hippocampal long-term potentiation in freely moving mice

This paper addresses the role of adenosine A₁R receptors (A₁R) on synaptic efficacy in the hippocampus. Adenosine A₁ receptors (A₁R) have known inhibitory effects in the CNS by both hyperpolarizing neurons and inhibiting Ca²⁺ influx. This inhibitory effect leads to a decrease in glutamate release. Glutamate, in turn, activates NMDA receptors, which is thought to lead to long-term potentiation (LTP). Thus, we hypothesized that elimination of A₁R´s would lead to an increase in both NMDA activation and LTP. To assess the role of adenosine on synaptic plasticity in the hippocampus, LTP was induced in freely moving wild type (normal) and A₁R knockout (KO) mice, which lack the gene coding for the A₁R. Preliminary results show that LTP is enhanced in KO mice compared to controls, which corresponds to the inhibitory effects of adenosine.