Neurotransmitter systems involvement

A variety of different methodologies has been employed to investigate the neurotransmitter systems involved in control of behavioral states. Biochemical experiments have elucidated the pathways and enzymes involved in the synthesis, degradation, release and reuptake of different neurotransmitters. Immuno-histochemical techniques have allowed the visualization of their cellular and sub-cellular distribution throughout the nervous system as well as the distribution of their receptors and uptake systems. Chemical sampling techniques, including... 

Myhrer T. 2003. Neurotransmitter systems involved in learning and memory in the rat A meta-analysis based on studies of four behavioral tasks. Brain Res Rev 41 268-287. 

The binding of PCP to its receptor initiates a series of coupled neurochemical events eventually leading to the expression of behavior. One such coupling reaction was described by BLAUSTEIN as a blockade of transmembrane channels that transport K+ into the neuronal cells. Since K+ movements are part of the process of neurotransmission between neurons, this effect of PCP may explain the results of studies by MARWAH and by JOHNSON, in which several neurotransmitter systems were shown to be involved in the actions... 

In rodents, PCP produces not only ataxia, but also stereotyped behavior and hyperactivity. The PCP-induced stereotyped behavior is thought to be due to changes in serotonergic and dopaminergic systems (Nabeshima et al. 1983 Martin et al. 1979 Sturgeon et al. 1981). It is not known whether PCP receptors mediate PCP-induced hyperactivity or stereotyped behavior or even the effect on neurotransmitter systems. It is also possible that mu, kappa, or sigma opioid receptors are involved (Castellani et al. 1982). 

There is evidence for the contribution of serotonin dysfunction to mania, and in the mechanism of action of mood stabilizers [19], however, specific data on the serotonergic system and mania are fewer and variable. Moreover, altered functioning of other neurotransmitters in mania such as norepinephrine, dopamine, acetylcholine, and GABA, and their interaction with serotonin, are also likely to be involved in the pathogenesis of mood disorders. Differences in these neurotransmitter systems possibly underlie differences in the pathogenesis of depressive and manic episodes. 

The effects of Li+ upon this system have been reviewed in depth by Mork [131]. Animal studies originally demonstrated that Li+ inhibits cAMP formation catalyzed by adenylate cyclase in a dose-dependent manner [132]. The level of cAMP in the urine of manic-depressive patients changes with mental state, being abnormally elevated during the switch period between depression and mania it is proposed that Li+ s inhibitory effect upon adenylate cyclase activity may correct this abnormality. Subsequent research, in accord with the initial experiments, have shown that Li+ s interference with this second messenger system involves more than one inhibitory action. At therapeutic levels, Li+ inhibits cAMP accumulation induced by many neurotransmitters and hormones, both in... 

Hong JS, Tilson HA, Uphouse LL, et al. 1984. Effects of chlordecone exposure on brain neurotransmitters Possible involvement of the serotonin system in chlordecone-elicited tremor. Toxicol Appl Pharmacol 73 336-344. 

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