Serotonin receptors in hippocampus. The functional glia-neuron-vascular cells network uses several serotonin receptors (5-HTRs). The 7TMD images of each subtype receptor are represented with the defined number of exons that code for the mature protein (Bockaert et al., 2006) [44]; putative intron location in correspondent pre-mRNA is marked by a lightning symbol (↯); alternative splicing sites are marked with stars (⋆⋆⋆). Neuron metabotropic 5-HTRs are mainly somatodendritic volume receptors although there is an association with synaptic specializations for some of them. 5-HT3 with the five 4TMD subunits of a ligand activated ion channel is shown as synaptic receptor although this fact remains to be determined in hippocampus. Microglia is also included in the network for its relevance in pathophysiological responses, with 5-HT2B receptor expression (Capone et al., 2007) [90]. The 12TMD image of the serotonin transporter (SERT; 5-HTT) and vesicular monoamine transporter (VMAT) are represented in the serotonergic neuron and only SERT in the astrocyte.
