Second Messengers of Octopamine Receptors in the Snail Lymnaea
We describe octopamine responses of 3 large buccal neurons of Lymnaea and test the hypothesis that these are cAMP-dependent.
The B1 neuron is excited by octopamine and the depolarisation is significantly enlarged (P < 0.05) by application of the blocker of cAMP breakdown, 3-isobutyl-l-methylxanthine (IBMX). The Bl neuron is also depolarised by forskolin, an activator of adenylyl cyclase.
The B2 and B3 neurons are inhibited by octopamine, and the response is not affected by IBMX. Both cells are excited by forskolin.
We conclude that the Bl neuron response to octopamine is likely to be mediated by cAMP, while the B2 and B3 responses are cAMP-independent.
KeywordsLymnaea stagnalis feeding octopamine receptor second messenger
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- 3.Chang, D. J., Li, X. C., Lee, Y. S., Kim, H. K., Kim, U. S., Cho, N. J., Lo, X., Weiss, K. R., Kandel, E. R., Kaang, B. K. (2000) Activation of a. heterologously expressed octopamine receptor coupled only to adenylyl cyclase produces all the features of presynaptic facilitation in Aplysia sensory neurons. Proc. Natl. Acad. Sci. U. S. A., 97, 1829–1834.CrossRefGoogle Scholar
- 8.Gerhardt, C. C., Bakker, R. A., Piek, G. J., Planta, R. J., Vreugdenhil, E., Leysen, J. E., van Heerikhuizen, H. (1997) Molecular cloning and pharmacological characterization of a. molluscan octopamine receptor. Mo/. Pharmacol. 51, 293–300.Google Scholar
- 9.Gerhardt, C. C., Lodder, H. C., Vincent, M., Bakker, R. A., Planta, R. J., Vreugdenhil, E., Kits, K. S., van Heerikhuizen, H. (1997) Cloning and expression of a. complementary DNA encoding a. molluscan octopamine receptor that couples to chloride channels in HEK293 cells. J. Biol. Chem. 272, 6201–6207.CrossRefGoogle Scholar
- 12.Rose, R. M., Benjamin, P. R. (1981) Interneuronal control of feeding in the pond snail Lymnaea stagnalis. 1. Initiation of feeding cycles by a. single buccal interneurone. J. Exp. Biol. 92, 187–201.Google Scholar
- 13.Rose, R. M., Benjamin, P. R. (1981) Interneuronal control of feeding in the pond snail Lymnaea stagnalis. 2. The interneuronal mechanism generating feeding cycles. J. Exp. Biol. 92, 203–228.Google Scholar
- 18.Vehovszky, A., Hiripi, L., Elliott, C. J. H. (2000) Octopaminergic synaptic connections between the identified buccal OC neurons and members of the buccal feeding network or the pond snail Lymnaea stagnalis. Eur. J. Neurosci. 12, 92.Google Scholar
- 19.Whim, M. D., Evans, P. D. (1991) The role of cyclic-amp in the octopaminergic modulation of flight-muscle in the locust. J. Exp. Biol. 161, 423–438.Google Scholar
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