Chronic activation of the 5-HT(2) receptor reduces 5-HT neurite density as studied in organotypic slice cultures

摘要: The serotonin system densely innervates the brain and is implicated in psychopathological processes. Here we studied effect of pharmacological compounds on outgrowth serotonergic projections using organotypic slice co-cultures hippocampus dorsal raphe nuclei. Immunocytochemical analysis showed that several neurites had grown into target within 7 days culture, after which neurite density stabilized. These expressed serotonin-synthesizing enzyme Tryptophan hydroxylase transporter contained serotonin-positive varicosities also accumulated presynaptic markers. Chronic application a 5-HT(2) agonist reduced density, without effects survival neurons. In contrast, 5-HT(1A) or inhibitor fluoxetine did not affect density. We conclude connectivity was reproduced vitro inhibited by chronic activation receptor.