Identification of 5-HT Receptor Sub-types in a Homogeneous Population of Presumptive Serotoninergic Neurones

Serotonin decreases generation of dopaminergic neurons from mesencephalic precursors via serotonin type 7 and type 4 receptors

“…A developmental role for 5-HT 2 receptors has been reported in several studies, with the role of 5-HT 2B being particularly interesting during early embryonic development (Gaspar et al, 2003). Data obtained with the clone 1C11 (Loric et al, 1995;Mouillet-Richard et al, 2000), immortalized 5-HT precursors (Jackson et al, 1997), and rat brain (Bonaventure et al, 2002) suggest that 5-HT 2B may be an autoreceptor. However, additional research is necessary to clarify the role of 5-HT 2 receptors in neural development.…”

“…They have been less extensively investigated than other 5-HT receptors, and much less is known about them, particularly their possible role in neuronal development (Raymond et al, 2001;Hoyer et al, 2002;Glennon, 2003;Hedlund and Sutcliffe, 2004). However, there is increasing evidence of the significant role of these receptors in brain development (Waeber et al, 1996;Jackson et al, 1997;Beique et al, 2004). In the present study, treatment with 5-HT 4 or 5-HT 7 antagonists induced a significant increase in the generation of DA neurons in neurospheres, and treatment with 5-HT 4 or 5-HT 7 agonists blocked the 5,7-DHT-induced increase in generation of DA cells.…”

“…Several previous studies have detected receptors in the raphe nuclei Ruat et al, 1993;Duncan et al, 1999) and it has been suggested that 5-HT receptors may act as autoreceptors on 5-HT neurons (Roberts et al, 2001). Interestingly, 5-HT 7 gene expression has been observed in immortalized serotonergic precursors, and this expression was lost after cell differentiation (Jackson et al, 1997). However, the present experiments using the toxin 5,7-DHT + 5-HT 4 or 5-HT 7 agonists, and those using Ara-C + 5-HT 4 or 5-HT 7 antagonists show that the glial receptors play a major role, and additional studies are necessary to clarify the role of the 5-HT 7 and 5-HT 4 receptors observed in serotonergic cells in the present study.…”