Bromodeoxyuridine (BrdU) incorporation during DNA synthesis, expression of nestin (intermediate neurofilament expressed after differentiation of neuroepithelial and neural crest-derived NSCs), differentiation into astrocytes, and various stages of neurons were demonstrated. Sensory features including expression of vesicular glutamate transporter2 (VGluT2—glutamate terminals), transient receptor potential vanilloid1 (TrpV1—capsaicin-sensitive sensory neurons), and phosphorylated 200 kDa neurofilaments (pNF200—capsaicin-insensitive myelinated sensory neurons) were tested. A specific capacity of sensory neurons to temporarily express serotonin transporter (5-HTT) during early stages of development was analyzed. Expression of 5-HTT in neural crest-derived structures such as DRG has been previously reported (16,41). Serotonin (5-HT) is multifunctional during development, serving for guidance, trophic support, and neurotransmission, but 5-HT is not synthesized locally, rather 5-HTT facilitates with uptake into developing sensory neurons (12,41).
