Muscarinic receptors striatum

Hersch, SM, Guten Kunst, CA, Rees, HD, Heilman, CT and Levey, AJ (1994) Distribution of M1-M4 muscarinic receptor proteins in the rat striatum. Light and electron microscopic immunochemistry using subtype-specific antibodies. J. Neurosci. 141 3351-3363. 

Both nicotinic and muscarinic receptors are widespread in the CNS. Muscarinic receptors with a high affinity for pirenzepine (PZ), M, receptors, predominate in the hippocampus and cerebral cortex, whereas M2 receptors predominate in the cerebellum and brainstem, and M4 receptors are most abundant in the striatum. Central muscarinic and nicotinic receptors are targets of intense pharmacological interest for their potential roles in regulating abnormal neurological signaling in Alzheimer s disease, Parkinson s disease and certain seizure disorders. Nicotinic receptors are largely localized at prejunctional sites and control the release of neurotransmitters [10,11],... 

Acetylcholine. Most of the acetylcholine in the basal ganglia is found in the striatum, as the neurotransmitter of the large spiny interneurons, which account for about 3% of all striatal neurons. Both muscarinic and nicotinic cholinergic receptors are found in the striatum. Postsynaptic muscarinic receptors may inhibit transmitter release from... 

Dravid AR. (1983). Deficits in cholinergic enzymes and muscarinic receptors in the hippocampus and striatum of senescent rats effect of chronic Hydergine treatment. Arch Int Pharmacodyn Ther. 264(2) 195-202. 

The tropane alkaloids, especially hyoscine (scopolamine) (18), have been used to treat PD since they increase DA activity by antagonizing cholinergic activity at the muscarinic receptors in the striatum. The naturally occurring alkaloids, foimd in various genera of the Solanaceae, are not... 

The efficacy of anticholinergic drugs in parkinsonism is likely due to the ability to block muscarinic receptors in the striatum. In the absence of the inhibitory action of dopamine, the actions of the intrastriatal cholinergic interneurons are unopposed, yielding enhanced stimulation of muscarinic receptors. Blockade of these receptors reduces striatal activity. The muscarinic antagonists exert only modest antiparkinsonian actions and thus are most commonly used during the early stages of the disease or as an adjunct to levodopa therapy. 

Answer C. Muscarinic receptor antagonists such as benztropine, trihexyphenidyl, and diphenhydramine are used to manage the reversible extrapyramidal dysfunction (e.g., pseu-do-Parkinsonism) that results from treatment with drugs that block DA receptors in the striatum. Drugs that activate DA receptors, although theoretically possible, require doses that are toxic and exacerbate psychoses. Because the actions of DA in the striatum lead to... 

Mechanism of action These drugs decrease the excitatory actions of cholinergic neurons on cells in the striatum by blocking muscarinic receptors. 

Thioridazine has greater alpha adrenoceptor-blocking actions Haloperidol activates GABAergic neurons in the striatum Thioridazine has greater blocking actions on brain muscarinic receptors Haloperidol acts presynaptically to block dopamine release Which one of the following statements concerning the treatment of bipolar affective disorder is accurate ... 

Huff, R. A., Corcoran, J. I., Anderson, J. K., and Abou-Donia, M. B. (1994). Chlorpyiifos oxon binds directly to muscarinic receptors and inhibits cAMP accumulation in rat striatum. J. Pharmacol Exp. Ther. 269,329-335. 

Liu. J.. Chakj aboni, T, and Pope, C. (2tX)2). In vitro effects t f organophosphorus anticholinesterases on muscarinic receptor-mediated inhibition of acetylcholine release in rat. striatum. Toxicol. Appl. Pharmacol. 178, 102-108. 

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