Activin type II receptors in embryonic dorsal root ganglion neurons of thechicken

Activin induces neuropeptide expression in thicken ciliary ganglion neurons . To determine if activin might also influence neuropeptide expression in d eveloping sensory neurons, we examined,whether type II activin receptors ar e expressed during embryonic development of the chicken dorsal root ganglia (DRG), and also examined the effects of activin on neuropeptide! expressio n in cultured DRG neurons, Using reverse transcription polymerase chain rea ction (rtPCR), we detected mRNAs for both the activin receptors type IIA (A ctRIIA) and type IIB (ActRIIB) in DRG from embryonic day 7 through posthatc h day 1, With bl situ hybridization, we found that morphologically identifi able neurons express mRNAs for both ActRIIA and ActRIIB, With developmental age, a subset of neurons that hybridizes more intensely with riboprobes to these receptor mRNAs becomes evident. A similar pattern of expression is o bserved with immunocytochemical staining using antisera against activin typ e II receptors. To examine whether embryonic DRG cells respond to activin w e treated dissociated cultures of DRG with activin A and assessed the expre ssion of vasoactive intestinal peptide (VIP) and calcitonin gene related pe ptide (CGRP) mRNAs using semiquantitative rtPCR, Activin treatment results in an increase in VIP mRNA, but does not affect CGRP mRNA levels. These obs ervations indicate that neurons in the embryonic chicken DRG can respond to activin and suggest that activin has the potential to play a role in the d evelopment and function of DRG sensory neurons. (C) 2001 John Wiley & Sons, Inc.