Depolarizing stimuli induce high levels of dopamine synthesis in fetal rat sensory neurons.
To investigate the role of activity-dependent mechanisms in sensory transmitter development, we examined the effect of depolarizing stimuli on tyrosine hydroxylase expression and dopamine synthesis in cells of the fetal rat petrosal ganglion, a model of catecholaminergic sensory neurons. Although dopaminergic traits are normally detectable in only 10-20% of ganglion neurones, exposure to depolarizing concentrations of potassium chloride (40 mM) or veratridine (10 microM) in culture induced tyrosine hydroxylase expression in 100% of petrosal neurons and a 10-fold increase in dopamine content. Tyrosine hydroxylase expression remained elevated in a subset of neurons following return to control conditions, suggesting that chronic depolarization elicits a phenotypic switch in some cells. These data show for the first time that transmitter expression in developing sensory neurons can be regulated by activity-related cues.
Hertzberg
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Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
Brosenitsch
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Katz
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DM
D000818:Animals; D002384:Catalysis; D002478:Cells, Cultured; D004298:Dopamine / Q000096:biosynthesis*; D005314:Embryonic and Fetal Development / Q000502:physiology; D005724:Ganglia / Q000187:drug effects* / Q000196:embryology / Q000378:metabolism; D005930:Glossopharyngeal Nerve / Q000187:drug effects* / Q000196:embryology / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D009475:Neurons, Afferent / Q000187:drug effects* / Q000378:metabolism; D010641:Phenotype; D011189:Potassium Chloride / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014446:Tyrosine 3-Monooxygenase / Q000096:biosynthesis*
D011189:Potassium Chloride; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine