Short-term response of postnatal rat vestibular neurons following brain-derived neurotrophic factor or neurotrophin-3 application.
The effects of the application of brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) neurotrophins on the intracellular calcium level ([Ca2+]i) were studied in vestibular ganglion neurons (VGNs) from postnatal day 3 (P3) rats cultured for 50 hr. We first assessed the expression of trkB and trkC mRNA receptors in cultured VGNs. Immunobloting and immunocytochemistry confirmed the presence of the neurotrophin receptors on neurons. Both neurotrophins induced transient [Ca2+]i elevations in VGNs: BDNF-treated neurons responded in 65% and NT-3-treated neurons in 56%. The responses could be inhibited by anti-BDNF or anti-NT-3 antibodies. The [Ca2+]i elevation was dependent on extracellular calcium since it was abolished in calcium-free medium but also implicates the release of calcium from intracellular stores as tested by prior depletion with thapsigargin. Our results suggest the implication of a short-term calcium regulation in VGNs, which could reflect specific fast effects of neurotrophins in the early postnatal rat vestibular system.
Montcouquiol
M
M
INSERM U432, Neurobiologie et Développement du Système Vestibulaire, Université de Montpellier II, France.
Valat
J
J
Travo
C
C
Sans
A
A
D000818:Animals; D000831:Animals, Newborn; D000906:Antibodies / Q000494:pharmacology; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D017950:Ganglia, Sensory / Q000502:physiology*; D017403:In Situ Hybridization; D007700:Kinetics; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D020933:Neurotrophin 3; D015345:Oligonucleotide Probes; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis; D020801:Receptor, Ciliary Neurotrophic Factor; D020812:Receptor, trkC; D017475:Receptors, Nerve Growth Factor / Q000096:biosynthesis; D014158:Transcription, Genetic; D014725:Vestibular Nerve / Q000502:physiology*
D000906:Antibodies; D019208:Brain-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D020933:Neurotrophin 3; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D020801:Receptor, Ciliary Neurotrophic Factor; D017475:Receptors, Nerve Growth Factor; D020794:Receptor Protein-Tyrosine Kinases; D020812:Receptor, trkC; D002118:Calcium