Implication of ATP receptors in brain functions

The possible implication of P₂-purinoceptors in brain functions is reviewed. Involvement of P₂-purinoceptors in memory and learning (Section 2) is suggested by ATP release from hippocampal slices, induction of fast synaptic currents in cultured hippocampal neurons and long-lasting enhancement of the population spikes, as well as ATP release on glutamate stimulation to evoke an increase in intracellular Ca²⁺ in hippocampal cells. Moreover, mRNAs for certain types of P(2X)-purinoceptors are present in the hippocampus. It is likely, therefore, that ATP may be involved in modulation of synaptic efficiency in the hippocampus. The implication of ATP in schizophrenia is suggested by the fact that antipsychotic drugs inhibit ATP-evoked responses in PC12 cells without blocking the action of dopamine D₂ receptors. Involvement of P₂-purinoceptors in Sections 4 ('Pain and cognition') and 5 ('Central regulation of the autonomic system') are also discussed.