Ganglia, basal

The area of the brain enclosing the third ventricle is the diencephalon. This area consists of several important structures, including the thalamus and hypothalamus. The thalamus contains distinct nuclei that are crucial in the integration of certain types of sensations and their relay to other areas of the brain (such as the somatosensory cortex). The hypothalamus is involved in the control of diverse body functions including temperature control, appetite, water balance, and certain emotional reactions. The hypothalamus is also 

In a recent light microscopical study it was suggested that many afferents to the ventral striatum from the amygdala in the rat might be glutamatergtic (McDonald, 1996). 

In combined tracing and immunocytochemical studies in the rat it was shown that the PPN, or at least a part of it, sends Glu-enriched fibers to the STN (Bevan and Bolam, 1995), and to the entopeduncular nucleus (Clarke et al., 1997). The latter authors could, furthermore, demonstrate that a significant portion of labeled axon terminals from the PPN displayed high levels of immunoreactivity against both Glu and choline acetyltransferase, suggestive of a co-localization of Glu and acetylcholine. 

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Dopamine. Dopamine (DA) (2) is an intermediate in the synthesis of NE and Epi from tyrosine. DA is localized to the basal ganglia of the brain and is involved in the regulation of motor activity and pituitary hormone release. The actions of DA are terminated by conversion to dihydroxyphenylacetic acid (DOPAC) by monoamine oxidase-A and -B (MAO-A and -B) in the neuron following reuptake, or conversion to homovanillic acid (HVA) through the sequential actions of catechol-0-methyl transferase (COMT) and MAO-A and -B in the synaptic cleft. 

Basal ganglia are a group of subcortical nuclei which are essential for the coordination of movements (so-called extrapyramidal system). They include the caudate nucleus, putamen, globus pallidus, and lenti-form nucleus. Damage of the basal ganglia results in involuntary movements, as are observed in Parkinson s disease and Huntington s chorea. 

Parkinson s disease (PD) 1. In a non-human primate model of PD endocannabinoid levels are elevated in the basal ganglia and may contribute to the generation of parkinsonian symptoms and/or to expression of levodopa-induced dyskinesia. The cerebrospinal fluid of untreated PD patients contains elevated levels of AEA 1. CB-) antagonists or biosynthesis inhibitors... 

As early as 1961, the first generation of MAO inhibitors (iproniazid, isocarboxazide) were employed for the treatment of Parkinson s disease (PD). However, because of the severe side effects, such as cheese reaction, they were abandoned. The realization that the basal ganglia (extrapyramidal region) of human brain contained mostly MAO-B, which metabolized... 

In summary, main structures involved in the action of psychostimulants can be divided into cortical (mainly prefrontal cortex) and subcortical (basal ganglia and related structures, LC and cerebellum) ones. Figure 1 gives a schematic overview of the connections between these structures, omitting the cerebellum due to lack of precise information. 

Bartter s Syndrome Basal Activity Basal Ganglia Basement Membrane Basophils Bax... 

Complex V catalyzes the phosphorylation of ADP to ATP. Deficiencies of complex V are rare and clinical presentation is usually nonprogressive muscle weakness. One subject included growth retardation, sensorineural deafness, and involvement of basal ganglia, which are occasional features of various other respiratory chain abnormalities. 

Pradhan S, Pandey N, Phadke RV, et al. 1997. Selective involvement of basal ganglia and occipital cortex in a patient with acute endosulfan poisoning. J Neurol Sci 147(2) 209-213. 

So far, little is known about this novel 5-HTid receptor but, in the rat and human, its mRNA is found, albeit in low concentrations, in the basal ganglia, nucleus accumbens, hippocampus, frontal cortex and Raphe nuclei. It is negatively coupled to adenylyl cyclase and is possibly located presynaptically, on both the 5-HT neuronal cell body and terminals, but this has yet to be confirmed. 

In order to understand how the symptoms of PD could arise from a loss of striatal DA and what can be done to replace it and treat PD, it is necessary to know something of basal ganglia circuitry and the role of DA in it. The scheme to be outlined should, however, be regarded as a working template rather than fully proven fact but there is much evidence for it (Fig. 15.2). Certainly the striatum, i.e. the putamen and caudate nucleus, is accepted as the main receiving area in motor circuits. Information coming to... 

Figure 15.2(a) A schematic presentation of possible normal basal ganglia circuitry. Activity in the cortico-thalamic pathway is modulated by striatal control of the globus pallidus (pallidum) through two pathways, the indirect pathway (Ind Path) to the external pallidum/globus pallidus (GPext) and the subthalamic nucleus (SThN) and the direct pathway (Dir Path) to GPint. Scheme... 

Figure 15.2(b) A schematic presentation of possible basal ganglia circuitry in Parkinson s disease. In PD there is little or no inhibitory nigrostriatal input to the striatum so the Ind Path is active and GPext is inhibited. This will then have less depressant effect on the SThN which will be free to drive the GPint (and SNr) and so reduce cortico-thalamic traffic and produce akinesia. See text for detail. Pathway activity — low — normal — high... 

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