Serotonin release

Rudnick, G and Wall, SC (1992) /7-Chloroamphetamine induces serotonin release through serotonin transporters. Biochemistry 31 6710-6718. 

Petty, F, Kramer, G, Wilson, L and Jordan, S (1994) In vivo serotonin release and learned helplessness. Psychiatry Res. 52 285-293. 

COMMENT It seems as though that might be a good tool to deteimine whether the diserimination really does relate to serotonin release because, clearly, it has been shown to block the serotonin release in vivo. If it does not block the drug discrimination it seems that it is not consistent with the idea that that is a consequence of serotonin release. 

There is a recent clinical report by Emil Coeearo and colleagues that I think might be relevant to the kind of thing you have done in rats. They have been looking at endocrine responses to fenfluramine in humans as a marker of central serotonergic function. And they have observed an increase in serum prolactin concentration, which is felt to be due to serotonin release. They reported that, in subjects who received a seeond dose of fenfluramine within 12 days after the first dose, that there was a blunted response to serum prolactin. 

Kele, M., Ohmacht, R., Determination of serotonin released from coffee wax by liquid chromatography, J. Chromatogr. A., 730 (1+2), 59, 1996. (CA124 337857v)... 

Portas, C. M., Thakkar, M., Rainnie, D. McCarley, R. W. (1996). Microdialysis perfusion of 8-hydroxy-2-(di-n-propylamino)tetrahn (8-OH-DPAT) in the dorsal raphe nucleus decreases serotonin release and increases rapid eye movement sleep in the freely moving cat. J. Neurosci. 16, 2820-8. 

Rudnick, G. and Wall, S.C., The molecular mechanism of ecstasy [3,4-methylenedioxy-metham-phetamine (MDMA)] serotonin transporters are targets for MDMA-induced serotonin release, Proc. Natl. Acad. Sci. U.S.A. 89(5), 1817-1821, 1992. 

Baumann, M.H., Ayestas, M.A., Dersch, C.M., and Rothman, R.B., l-(m-Chlorophenyl)piperazine (mCPP) dissociates in vivo serotonin release from long-term serotonin depletion in rat brain, Neuropsychopharmacology 24(5), 492-501, 2001. 

Kirby, L.G., Kreiss, D.S., Singh, A., and Lucki, I., Effect of destruction of serotonin neurons on basal and fenfluramine-induced serotonin release in striatum, Synapse 20(2), 99-105, 1995. 

Reitstetter R, Lukas RJ, Gruener R. (1999). Dependence of nicotinic acetylcholine receptor recovery from desensitization on the duration of agonist exposure. J Pharmacol Exp Ther. 289(2) 656-60. Ribeiro EB, Bettiker RL, Bogdanov M, Wurtman RJ. (1993). Effects of systemic nicotine on serotonin release in rat brain. Brain Res. 621(2) 311-18. 

Maries RJ, Kaminski J, Arnason JT, Pazos-Sanou L, Heptinstall S, Fischer NFI, Crompton CW, Kindack DG, Awang DV. (1992). A bioassay for inhibition of serotonin release from bovine platelets. J Nat Prod. 55(8) 1044-56. 

The sensory neuron from the tail makes a synapse with the modulating neuron, known as an intemeuron. Its job is to fine-tune the response of the sensory neuron to stimulation. Note that the intemeuron synapses with both the cell body and the presynaptic terminal of the sensory neuron. The neurotransmitter released by the intemeuron into these synapses is serotonin (also a key neurotransmitter in the human nervous system). The net effect of the serotonin release is to strengthen the connection between the sensory neuron and the motor neuron. It remains to explain how this happens that, too, has been tracked down in molecular detail. 

Conklyn, M. J., Kadin, S. B., and Showell,H. J. (1990) Inhibition of IgE-mediated A-acetylglucosaminidase and serotonin release from rat basophilic leukemia cells (RBL-2H3) by Tenidap A novel anti- inflammatory agent. Int. Arch. Allerg. Appl. Immunol. 91, 369-373. 

SAD, is possibly linked to a decreased serotonin turnover. Such a hypothesis is supported by the fact that the serotonin releasing agent D-fen luramine is effective in treating SAD. Chronobiology is clearly an important area of research for the psychopharmacologist which needs more attention. 

Gastrointestinal tract. Serotonin released from myenteric neurons or enterochromaffin cells acts on 5-HT3 and 5-HT4 receptors to enhance bowel motility and enteral fluid secretion Cisapride is a proldnetic agent that promotes propulsive motor activity in the stomach and in small and large intestines. It is used in motility disorders. Its mechanism of action is unclear, but stimulation of 5HT4 receptors may be important... 

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