Cyclic nucleotide homeostasis and axonal G proteins in the squid Loligo forbesi
Allen, T.J.A.; Rouot, B. (1995). Cyclic nucleotide homeostasis and axonal G proteins in the squid Loligo forbesi, in: Abbott, N.J. et al. (Ed.) Cephalopod neurobiology: neuroscience studies in squid, octopus and cuttlefish. pp. 35-52
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| Abstract |
This chapter reviews studies on signal: transduction coupling in the squid giant axon and its associated Schwann cell sheath, and the role of cyclic nucleotides and G-proteins in this coupling. The cAMP content of the axon is increased by external application of serotonin (5HT), and this effect is modulated by [Ca²+]i and is dependent on internal GTP; membrane G-proteins are implicated in the coupling. Lowering [Mg²+]i attenuates 5HT -evoked adenylate cyclase activity. The giant axon provides too little G-protein for analysis, but it has been possible to demonstrate G-proteins in the richer source of squid optic lobes. The cGMP content of the axon is increased by carbachol, and by nitroprusside, an agent activating cGMP synthesis. The role of G-proteins in Schwann cell-axon signalling is discussed. |
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