Neurotrophins alter the numbers of neurotransmitter-ir mature vagal/glossopharyngeal visceral afferent neurons in vitro.
Mature nodose and petrosal ganglia neurons (placodally derived afferent neurons of the vagal and glossopharyngeal nerves) contain TrkA and TrkC, and transport specific neurotrophins [nerve growth factor (NGF), neurotrophin-3 (NT-3), neurotrophin-4 (NT-4)]. This study evaluated neurotrophin influences on the presence of neuropeptides and/or neurotransmitter enzymes in these visceral sensory neurons. NGF, NT-3 and NT-4 (10-100 ng/ml) were applied (5 days) to dissociated, enriched, cultures of mature nodose/petrosal ganglia neurons, and the neurons processed for tyrosine hydroxylase (TH), vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP) and neurofilament (NF-200) immunocytochemistry. Addition of NGF to nodose/petrosal ganglia neuron-enriched cultures significantly increased the number of TH-immunoreactive (ir) neurons, decreased the number of VIP-ir neurons in the cultures, and did not affect the numbers of CGRP-ir neurons. The addition of an NGF neutralizing antibody attenuated the effects of NGF on TH and VIP-ir neurons. NT-3 increased the number of VIP-ir neurons in the nodose/petrosal ganglia cultures and did not alter the numbers of TH-, or CGRP-ir neurons. The addition of an NT-3 neutralizing antibody attenuated the effects of NT-3 on VIP-ir neurons. NT-4 had no significant effects on the numbers of TH, VIP and CGRP-ir neurons. The absence of neurotrophin-induced changes in the numbers of NF-200-ir neurons in culture showed the lack of neurotrophin-mediated changes in survival of mature vagal afferent neurons. These data demonstrate that specific neurotrophins influence the numbers of neurons labeled for specific neurochemicals in nodose/petrosal ganglia cultures. These data, coupled with previous evidence for the presence of TrkA and TrkC mRNA and of the retrograde transport of NGF and NT-3, suggest important roles for NGF and NT-3 in the maintenance of transmitter phenotype of these mature visceral afferent neurons.
Helke
C J
CJ
Department of Pharmacology and Neuroscience Program, Uniformed Services University of the Health Science, 4301 Jones Bridge Road, Bethesda, MD 20814-4799, USA. chelke@usuhs.mil
Verdier-Pinard
D
D
D000367:Age Factors; D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D002452:Cell Count / Q000706:statistics & numerical data; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005930:Glossopharyngeal Nerve / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D020932:Nerve Growth Factor / Q000494:pharmacology; D009414:Nerve Growth Factors / Q000378:metabolism / Q000494:pharmacology*; D016900:Neurofilament Proteins / Q000378:metabolism; D009475:Neurons, Afferent / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000378:metabolism*; D020933:Neurotrophin 3 / Q000494:pharmacology; D009620:Nodose Ganglion / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism
D009414:Nerve Growth Factors; D016900:Neurofilament Proteins; D018377:Neurotransmitter Agents; D020933:Neurotrophin 3; C051774:neurofilament protein H; D014660:Vasoactive Intestinal Peptide; D020932:Nerve Growth Factor; D014446:Tyrosine 3-Monooxygenase; D015740:Calcitonin Gene-Related Peptide; C073922:neurotrophin 4