95‐HT_2B Receptors Are Expressed by Neuronal Precursors in the Enteric Nervous System of Fetal Mice and Promote Neuronal Differentiation^a

Exogenous Serotonin Regulates Proliferation of Interstitial Cells of Cajal in Mouse Jejunum Through 5-HT2B Receptors

“…Previous studies have shown that the 5-HT 2B receptor is also expressed on neurons and smooth muscle cells. 15,16,61 We know that the 5-HT 2B receptor in the rodent gastrointestinal tract is involved in the maturation of neurons 15,29 and in rodent fundus contraction, 62 suggesting a more generalized role for the 5-HT 2B in the control of cell number and function.…”

“…11 Of the 7 classes of 5-HT receptors, 5-HT 1 , 5-HT 2 , 5-HT 3 , 5-HT 4 , and 5-HT 7 receptors are known to be expressed in the gastrointestinal tract and to affect gastrointestinal motor function. [12][13][14][15][16][17][18][19][20] The role of 5-HT in regulating gastrointestinal motility by mediating the transduction of luminal signals across the mucosa and by participating in enteric neurotransmission is well established. 21,22 There is however significant evidence, mostly from outside the gastrointestinal tract but also in studies on enteric nervous system development, that shows that 5-HT can also regulate cell survival and proliferation.…”

Expression of Ret-, p75NTR-, Phox2a-, Phox2b-, and tyrosine hydroxylase-immunoreactivity by undifferentiated neural crest-derived cells and different classes of enteric neurons in the embryonic mouse gut

“…Recently, a number of markers have become available that label migratory or post-migratory neural crest cells within the gastrointestinal tract of embryonic mice and rats. These include antibodies or probes to the receptor tyrosine kinase, Ret (Pachnis et al, 1993(Pachnis et al, , 1998Tsuzuki et al, 1995;Durbec et al, 1996;Watanabe et al, 1997), the low affinity neurotrophin receptor, p75 NTR (Baetge et al, 1990;Chalazonitis et al, 1994;Lo and Anderson, 1995), the endothelin-B receptor (Gariepy et al, 1998), the 5-HT2B receptor (Fiorica-Howells et al, 1998), the transgene DBHnlacZ (Kapur et al, 1992), the catecholamine synthetic enzyme, tyrosine hydroxylase (TH, Cochard et al, 1978;Teitelman et al, 1978;Jonakait et al, 1979) and the transcription factors MASH1 (Lo et al, 1991;Lo and Anderson, 1995;Lo et al, 1997), Phox2a (Tiveron et al, 1996), Phox2b (Pattyn et al, 1997), and SOX10 (Herbarth et al, 1998;Southard-Smith et al, 1998). In the intestine of adult mice, all enteric neurons show Phox2b immunoreactivity; it was therefore suggested that Phox2b antisera may label all enteric neuron precursors (Young et al, 1998).…”

Tracking Down the Migration of Mouse Neural Crest Cells

“…However, it is not expressed in mouse neural crest cells and is neither a per-manent nor a specific marker for neural crest cells of other species. HNK1/NC1 is expressed in various other cell types, including the neural tube, perichondrium and heart [38][39][40] [48], CrabpI [49], Prx1 and 2 [50], c-met [51], MASH1 [52][53][54][55], Phox2a [56][57][58], Phox2b [57][58][59], AP-2 [60,61], 5-HT2B receptor [62], tyrosinase [63], receptor tyrosine kinase Ret [64][65][66][67][68], neurotropin receptor p75 NTR [53,69,70], endothelin receptor B [71] and tyrosine hydroxylase [72][73][74]. Detection of these molecules has yielded significant information on the migration and development of neural crest cells.…”