Neurochemical studies

McEwen, B. S., Jones, K. and Pfaff, D. Hormonal control of sexual behavior in the female rat molecular, cellular and neurochemical studies. Biol. Reprod. 36 37 15,1987. 

Early postmortem neurochemical studies suggested reductions in presynaptic markers for the GABAergic neurons, such as glutamatic acid decarboxalase (GAD) activity, in prefrontal cortex in schizophrenic subjects... 

Schwarcz R, Hokfelt T, Fuxe K, Jonsson G, Goldstein M, Terenius L. (1979). Ibotenic acid-induced neuronal degeneration a morphological and neurochemical study. Exp Brain Res. 37(2) 199-216. Schwartz RH. (1988). Mescaline a survey. Am Earn Physician. 37(4) 122-24. 

A major component of a GC system is the detector. The general principles of detectors commonly used in neurochemical studies will be discussed here, and specific applications will be covered later in the chapter. 

Several useful publications describing early direct injection API-electrospray methods appHcable to neurochemical studies include studies on acetylchoHnesterase phosphonylation products (Barak et al., 1997) glycerophosphocholine lipids (Flarrison and Murphy, 1996) receptor antibody characterization (Lewis et al., 1994) neuropeptide Yanalogs (Beck-Sickinger et al., 1994) and large biomolecules (Loo et al.,... 

Herregodts P. 1991. Neurochemical studies of monoaminer-gic neurotransmitters in the central nervous system. VUB Press Brussels pp. 219-231. 

Figure 30-13 Section through a rat brain. This brain, which has been very widely used in neurochemical studies, appears superficially to be quite different from the human brain (Fig. 30-1), which is characterized by its large cerebral cortex. However, basic pathways are the same. Some major pathways for glutamate-secreting (glutamatergic) neurons are marked by arrows. Most of these originate in the neocortex (outer layers of the cerebral cortex) and the hippocampus. From Nicholls.149 Courtesy of David G. Nicholls.

Mann JJ, Marzuk PM, Arango V, McBride PA, Leon AC, Tierney H. Neurochemical studies of violent and nonviolent suicide. Psychopharmacol Bull 1989 25 407-413. 

There is anatomical and pharmacological evidence that 5-HT1B receptors have an axonal localization in different cerebral pathways and inhibit neurotransmitter release (10,149,158,159). Therefore, most electrophysiological evidence of the role of 5-HT1B receptors in neuronal function is based on the assessment of inhibitory actions on evoked synaptic potentials or currents in target neurons, whereas neurochemical studies have examined direct effects on neurotransmitter release. 

Matsumoto M, Togashi H, Mori K, et al. Evidence for involvement of central 5-HT4 receptors in cholinergic function associated with cognitive processes behavioral, electrophysiological, and neurochemical studies. J Pharmacol Exp Ther 2001 296 676-682. 

Richter A, Ebert U, Nobrega JN, Vallbacka JJ, Fedrowitz M, Loscher W (1999) Immunohistochemical and neurochemical studies on nigral and striatal functions in the circling (ci) rat, a genetic animal model with spontaneous rotational behavior. Neuroscience 59 461-471. 

MinderaaRB, Anderson GM, VoUonar FR, Akkerhuis GW, Cohen DJ (1989) Neurochemical study of dopamine functioning in autistic and normal subjects. J Am Acad Child Adolesc Psychiatry 28 190-194... 

Bloch-Shilderman, E., Rabinovitz, I., Egoz, I., Raveh, L., Allon, N., Grauer, E., Gilat, E., Weissman, B.A. (2008). Subchronic exposure to low-doses of the nerve agent VX physiological, behavioral, histopathological and neurochemical studies. Toxicol. Appl. Pharmacol. 231 17-23. 

Neurochemical studies on 5-HT neuron homeostasis performed in SERT-KO mice in general recapitulate the observations gained in DAT-KO mice with respect to DA transmission (36,39). In initial studies, a lack of high-affinity [3H]5-HT uptake in brain synaptosomes from SERT-KO mice was found (24), but in primary neuronal cultures from embryonic SERT-KO mice, [3H]5-HT uptake, although very weak, was observed (15). In vivo microdialysis studies have shown that disrupted uptake of 5-HT in SERT-KO mice results in a substantial increase in extracellular levels of 5-HT (five- to sixfold) (89,90). A marked reduction (60%-80%) in 5-HT tissue levels was found in several brain regions of SERT-KO mice (24,89,90), suggesting deficient intraneuronal storage of 5-HT. Furthermore, 5-HT synthesis was disinhibited in SERT-KO mice (89). 

The cardiac safety of nomlfensin was established by measurements of cardiac conduction in depressed patients receiving therapeutic doses over 3 weeks, and it was less toxic than doxepin or amitriptyline In Isolated hearts. 3 Nomlfensin Inhibited NA uptake in the same way as TCA but its principal actions may be on dopaminergic (DA) systems, both as an uptake inhibitor and as an agonist.5 The metabolites (, Ri=0H, R2=H 2c, Ri= OCH3, R2=0H Ri=0H, R2=OCH3) Inhibit the uptake of DA and 5-HT, but another potential metabolite, the catechol (2e, Rx=R2=0H) is a potent DA agonist in behavioral and neurochemical studies. 5 However, the beneficial effects of 7 in parkinsonism may be due to its improvement of depressive s3nnptoms. 6... 

Voltammetric methods are of particular interest with regard to the selective determination of analytes in the presence of interferents. As a widely studied case, one can mention the determination of dopamine and other neurotransmitter catecholamines in the presence of interfering compounds, namely, ascorbic acid and/or uric acid. It is known that dopamine exerts a signilicani physiological role as extracellular chemical messenger whose loss in neurons can be associated to serious diseases such as Parkinsonism. Consequently, its determination in vitro and in vivo is an obvious target in neurochemical studies. 

Fonnum F (1991) Neurochemical studies on glutamate-mediated neurotransmission. In Meldrum BS, Moroni F, Simon RP, Woods JH (Eds), Fidia Research Foundation Symposium Series. Vol. 5 Excitatory Amino Acids. New York Raven Press, pp 15-25. 

Neurochemical studies using radiolabelled glutamate and some of the above analogues showed specific binding sites and uptake mechanisms [3, 14, 15]. The presence of these presumed postsynaptic receptors and transporter systems provided key support for the electrophysiological evidence for the transmitter role of L-glutamate. 

Behavioural and neurochemical studies have now clarified the controversy about the abuse liability of cannabinoids by demonstrating that such drugs fulfil most of the common features attributed to compounds with reinforcing properties. Cannabinoid rewarding properties have been identified using intracranial selfstimulation, conditioned place preference and intravenous self-administration paradigms. Furthermore, a cannabinoid withdrawal syndrome has also been characterized in different animal species (Lichtman and Martin 2002 Maldonado and Rodriguez de Fonseca 2002). 

Behavioral and neurochemical studies implicate a role for peripheral CBlRs in cannabinoid antinociception in models of acute, inflammatory, and neuropathic pain states. 

Early behavioral and neurochemical studies suggested the involvement of L-tryptophan in the mechanisms of analgesia. These studies were followed by many experiments on the possible involvement of serotonin in this phenomenon. At present, the physiological role of serotonin in pain and analgesia still remains to be fully explained. During the last decade, a number of studies have suggested that another route of metabolism of tryptophan, the kynurenine pathway, was involved in the control of neuronal activity. Some of the experimental studies are cited here. 

---