Ganglions

Mode of Motion. Nicotine, anabasine, and imidocloprid affect the ganglia of the insect central nervous system, faciUtating transsynaptic conduction at low concentrations and blocking conduction at higher levels. The extent of ionisation of the nicotinoids plays an important role in both their penetration through the ionic barrier of the nerve sheath to the site of action and in their interaction with the site of action, which is befleved to be the acetylcholine receptor protein. There is a marked similarity in dimensions between acetylcholine and the nicotinium ion. 

A systematic nomenclature for nAChRs has yet to evolve. An N nomenclature describes receptors present ia muscle as N. These are activated by phenyltrimethylammonium (PTMA) (15) and blocked by t5 -tubocurariae (16) and a-bungarotoxiu (a-BgT) (17). N2 receptors are present ia ganglia and are activated by l,l-dimethyl-4-phenylpipera2inium (DMPP) (18) and blocked by trimethaphan (19) and bis-quatemary agents, with hexamethonium (20) being the most potent. 

Amylin [106602-62-4] (75) (Fig. 4) is a 37-amino acid peptide having approximately 46% sequence similarity to CGRP (33). Amylin is present ia pancreatic P-ceUs along with insulin. It may function as a hormone ia glucoregulation and has been proposed as an etiologic factor ia certain forms of diabetes. Amylin is also present ia dorsal root ganglia (see INSULIN AND OTHER ANTIDIABETIC DRUGS). 

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. 

General types of physiological functions attributed to quaternary ammonium compounds are curare action, muscarinic—nicotinic action, and ganglia blocking action. The active substance of curare is a quaternary that can produce muscular paralysis without affecting the central nervous system or the heart. Muscarinic action is the stimulation of smooth-muscle tissue. Nicotinic action is primary transient stimulation and secondary persistent depression of sympathetic and parasympathetic ganglia. 

Acetylcholine is a neurotransmitter at the neuromuscular junction in autonomic ganglia and at postgangHonic parasympathetic nerve endings (see Neuroregulators). In the CNS, the motor-neuron collaterals to the Renshaw cells are cholinergic (43). In the rat brain, acetylcholine occurs in high concentrations in the interpeduncular and caudate nuclei (44). The LD q (subcutaneous) of the chloride in rats is 250 mg/kg. 

Feral and LeGall" have suggested that TBT may affect the neuroendocrine system, interfering with the release of a retrogressive factor from the cerebropleiiral ganglia. The effects of TBT on neuroendocrine function merit further study. 

Ganglionic blocking agent. A drug that blocks neurotransmission at the nicotinic receptors of the sympathetic ganglia, thus blocking vascular reflexes. 

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. 

These are a subset of sensory neurons having their cell bodies (small to medium size) in dorsal root and in cranial nerve ganglia and possessing nonmyelinated (C-type) or thinly myelinated (A-delta type) fibres. This subset of neurons express transient receptor potential vanilloid type 1 (TRPV1, or vanilloid, or capsaicin receptor) that is excited by capsaicin, the pungent ingredient of chilli. These neurons have been classified as polymodal nociceptors because they can be excited by various noxious stimuli. 

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. 

P2X2 Smooth muscle, CNS, retina, chromaffin cells, autonomic and sensory ganglia ATP>ATPyS>2- MeSATP > > a,p-meATP (pH + zinc sensitive) Suramin, isoPPADS, RB2, NF770, NF279 Intrinsic ion channel (particularly Ca2+)... 

Peripheral GI and vascular smooth muscle, sympathetic ganglia... 

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