Neuronal regulation of photo-induced pineal photoreceptor proteins in carp Catla catla.
In the present in vitro study on the pineal in carp Catla catla, specific agonist and antagonists of receptors for different neuronal signals and regulators of intra-cellular Ca(++) and cAMP were used to gather basic information on the neuronal signal transduction cascade mechanisms in the photo-induced expression of rod-like opsin and alpha-transducin-like proteins in any fish pineal. Western-blot analysis followed by quantitative analysis of respective immunoblot data for both the proteins revealed that photo-induced expression of each protein was stimulated by cholinergic (both nicotinic and muscarinic) agonists and a dopaminergic antagonist, inhibited by both cholinergic antagonists and a dopaminergic agonist, but not affected by any agonists or antagonists of adrenergic (alpha(1), alpha(2) and beta(1)) receptors. Moreover, expression of each protein was stimulated by voltage gated L type calcium channel blocker, adenylate cyclase inhibitor and phosphodiesterase activator; but suppressed by the activators of both calcium channel and adenylate cyclase, and by phosphodiesterase inhibitor. Collectively, we report for the first time that both cholinergic and dopaminergic signals play an important, though antagonistic, role in the photo-induced expression of photoreceptor proteins in the fish pineal through activation of a signal transduction pathway in which both calcium and cAMP may act as the intracellular messengers.
Department of Zoology, Visva Bharati University, Santiniketan, India.
Mohua
M
Seth
Saumen Kumar
SK
Maitra
D000818:Animals; D020013:Calcium Signaling / Q000502:physiology / Q000528:radiation effects; D002347:Carps / Q000033:anatomy & histology / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism / Q000528:radiation effects; D003624:Darkness; D029941:Fish Proteins / Q000378:metabolism / Q000502:physiology*; D008027:Light; D055537:Light Signal Transduction / Q000502:physiology / Q000528:radiation effects; D009419:Nerve Tissue Proteins / Q000378:metabolism / Q000502:physiology* / Q000528:radiation effects; D009474:Neurons / Q000378:metabolism* / Q000528:radiation effects; D009924:Organ Culture Techniques; D020419:Photoreceptor Cells, Vertebrate / Q000166:cytology / Q000378:metabolism*; D010870:Pineal Gland / Q000166:cytology / Q000378:metabolism* / Q000528:radiation effects; D017299:Rod Opsins / Q000378:metabolism / Q000528:radiation effects; D015398:Signal Transduction / Q000502:physiology; D015293:Transducin / Q000378:metabolism / Q000528:radiation effects
D029941:Fish Proteins; D009419:Nerve Tissue Proteins; D017299:Rod Opsins; D000242:Cyclic AMP; D015293:Transducin