UNASSIGNED: The 5-HT6 receptor (5-HT6R) is almost exclusively expressed in the brain and has emerged as a promising target for @entity73 , including @entity195 . In the present study, we have determined the cell types on which the 5-HT6R is expressed by colocalizing 5-HT6R mRNA with that of a range of neuronal and interneuronal markers in the @entity35 brain. Here, we show that 5-HT6R mRNA was expressed at high levels in medium spiny neurons in caudate putamen and in nucleus accumbens, as well as in the olfactory tubercle. Striatal 5-HT6R mRNA was colocalized with both @entity935 D1 and D2 receptor mRNA. 5-HT6R mRNA was moderately expressed in the hippocampus and throughout cortical regions in glutamatergic neurons coexpressing @entity3862 . A subset of @entity14019 -positive GABAergic interneurons (approximately 15%) expressed 5-HT6R mRNA in the cortex and hippocampus, the majority of which belonged to the 5-HT3a receptor (5-HT3aR)-expressing subpopulation. In contrast, 5-HT6R mRNA was only expressed to a minor extent in the parvalbumin and @entity1943 subpopulations. A subset of calbindin- and calretinin-positive GABAergic interneurons expressed 5-HT6R mRNA while only a very minor fraction of @entity12180 or NPY interneurons in forebrain structures expressed 5-HT6R mRNA. Serotonergic, dopaminergic or cholinergic neurons did not express 5-HT6R mRNA. These data indicate that the 5-HT6R is located on GABAergic and glutamatergic principal neurons, and on a subset of interneurons mainly belonging to the 5-HT3aR subgroup suggesting that the 5-HT6R is positioned to regulate the balance between excitatory and inhibitory signaling in the brain. These data provide new insights into the mechanisms of 5-HT6R signaling.

Distribution of serotonin receptor 5-HT6 mRNA in XXXX neuronal subpopulations: A double in situ hybridization study.

@entity935 :: ('MESH:D004298', 'Chemical') :: ['dopamine'] @entity73 :: ('MESH:D003072', 'Disease') :: ['cognitive disorders'] @entity3862 :: ('116638(Tax:10116)', 'Gene') :: ['vGluT1'] @entity12180 :: ('117064(Tax:10116)', 'Gene') :: ['VIP'] @entity14019 :: ('24379(Tax:10116)', 'Gene') :: ['GAD67'] @entity195 :: ('MESH:D000544', 'Disease') :: ["Alzheimer's disease"] @entity35 :: ('10116', 'Species') :: ['rat'] @entity1943 :: ('MESH:D013004', 'Chemical') :: ['somatostatin']
@entity35 :: (10116,Species) :: ['rat']
