Modulation by histamine H3 receptors of neurotransmitter release in the Basal Ganglia

Among the four G-protein coupled receptors (H1-H4) identified as the mediators of the biological effects of histamine, the H3 receptor (H3R) distinguishes for its almost exclusive expression in the nervous system and its dual function as auto- and hetero-receptor that enables H3Rs to modulate the histaminergic and other neurotransmitter systems. The basal ganglia are neuronal nuclei that form a sub-cortical circuitry responsible for integrating motor and sensorial information originated in the cerebral cortex and the thalamus. The abundant presence of H3Rs in the basal ganglia confers these receptors a preferential and strategic position to modulate both the incoming and the outgoing synaptic information. In this chapter we review the control by H3Rs of the release of the neurotransmitters involved in the basal ganglia circuitry.