Chapter 16 The functions of ATP receptors in the synaptic transmission in the hippocampus

Abstract

This chapter discusses the implications of ATP receptors in the function of the hippocampus. The chapter presents the information that ATP inhibits presynaptically the release of glutamate, an excitatory neurotransmitter from the hippocampus. Meanwhile, it has been reported that ATP stimulates the release of glycine, an inhibitory neurotransmitter from interneurons of dorsal horn. In hippocampus, ATP may stimulate the release of GABA from some interneurons. The inhibition of glutamate release and the stimulation of GABA and glycine release have the same effect as a negative feedback loop—that is, turning-down the activity of neurons stimulated by glutamate. ATP also activates microglia to release plasminogen, a type of neurotrophic factor, which promotes the development of mesencephalic dopaminergic neurons and enhances neurite outgrowth from explants of neocortical tissue. ATP may stimulate the reconstruction of synaptic networks through activating microglia. The chapter discusses several reports that show the trophic action of ATP itself in central nervous system (CNS). Thus, ATP may have a role in the protection of the function of neurons in hippocampus from over-stimulation by glutamate.