Neurotransmitters and their receptors

Neurotransmitters are recognized by receiving neurons, neuromuscular junctions, or end effector organs via receptors that lie on the postsynaptic membrane. Receptors are generally selective for the neurotransmitter that they bind. The type of signaling that is characteristic of a given neurotransmitter is usually the result of the form of receptor to which it binds. For example, some receptors, like the nicotinic acetylcholine receptor found in neuromuscular junctions, are ion channels. The stimulation of the nicotinic 

Calretinin-immunoreactivity differentiates the adult vestibulocerebellum from other lobules by the strong staining of the unipolar brush cells that prevail in the vestibulo-cerebellum, and the relatively low immunoreactivity in granule cells and parallel fibers (Section 6.1.5.). The distribution of calretinin-immunoreactivity also emphasized the extension of the vestibuloeerebellum, beyond the posterolateral fissure, into the ventral uvula and the paraflocculus. 

The compartmental organization of the white matter of the cerebellum as an expres- 

The Zebrin pattern is positively or negatively correlated with the distribution of other Purkinje cell markers, discussed by Hawkes (1992) and Leclerc et al. (1992), and in Sections 3.1.8. and 6.1.3. of this chapter. Notably, the distributions of PKC 5 (Chen and Hillman, 1993a) (Section 6.1.3.) and of nerve growth factor receptor protein (Section 

) in the Purkinje cells conform to the Zebrin pattern. The distribution of certain substances in the Bergmann glia appears to be linked to the Zebrin pattern this may be true for 5 -nucleotidase (Section 3.5.) and has been established for 3-fucosyl-acetyl-lactosamine (Bartsch and Mai, 1991) (Section 3.11.) that occurs preferentially in the Bergmann glia of the Zebrin-negative zones. 

Does the Zebrin pattern result from the interdigitation of two sets of Purkinje cells that differ in their biochemical properties and in their afferent and efferent connections The truth, probably, is less simple. Purkinje cells of the A and B zones of rat cerebellum, that project to the lateral vestibular nucleus, are uniformly Zebrin-negative and are delimited by Zebrin-positive bands and satellite bands (Fig. 143). Other zones, that can be defined by their corticonuclear and olivocerebellar connections, such as the lateral extension of the A zone of Buisseret-Delmas (1988a), include both Zebrin-positive and Zebrin-negative regions (Fig. 144). Morever, uniformly Zebrin-positive lobules, like lobule VII, the nodulus, the flocculus and the paraflocculus, contain a complex zonal substructure (Sections 6.1.4., 6.1.5. and 6.3.3.3.). 

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A variety of substances have been found to serve as neurotransmitters in the nervous system. Most of these have actions outside the nervous system as well. Classically, the term neurotransmitter implies ionotropic actions on neurons, while those with metabotropic actions are regarded as neuromodulators. This distinction is blurred, however, by the fact that many substances can have either action, depending on the receptor to which it binds. Table 2.1 summarizes the major classes of neurotransmitters and their receptor-effector mechanisms. 

Messenger targets drugs that target neurotransmitters and their receptors (chapter 4)... 

NEUROTRANSMITTERS AND THEIR RECEPTORS 4.2.5.2 Cholinergic Antagonists Neuromuscular Blocking Agents... 

NEUROTRANSMITTERS AND THEIR RECEPTORS 4.5.3.2 Serotonin Reuptake Inhibitors... 

NEUROTRANSMITTERS AND THEIR RECEPTORS 4.6.1 Structure, Conformation, and Equilibria of Histamine... 

NEUROTRANSMITTERS AND THEIR RECEPTORS 4.7.7 GABAergic Drugs Anticonvulsants... 

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