Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.1.107 (DAT)
1,471 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The loss of cholinergic neurons, particularly in the forebrain, plays an important role in the pathophysiology of Alzheimer's disease (DAT). This concept has lead to the effective treatment of DAT by means of acetylcholine (Ach) esterase inhibitors. G-protein-coupled muscarinic acetylcholine receptors (mAchR) are classified in 5 subtypes, the M1 receptor stimulation and M2 inhibition being especially associated with cognitive skills. Modified cerebral muscarinic receptor profiles in patients with Alzheimer's disease in addition to loss of Ach releasing neurons help us to understand the pathophysiology of dementia and offer potential therapeutic approaches. Specific agonists and antagonists of muscarinic receptors are discussed as possible treatment options in DAT. Experimental results postulate a positive long lasting modulation of the pathological neuronal protein pattern in addition to their cholinomimetic effect.
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PMID:On the physiological relevance of muscarinic acetylcholine receptors in Alzheimer's disease. 1630 79

The opposing action of dopamine and acetylcholine has long been known to play an important role in basal ganglia physiology. However, the quantitative analysis of dopamine and acetylcholine signal interaction has been difficult to perform in the native context because the striatum comprises mainly two subtypes of medium-sized spiny neurons (MSNs) on which these neuromodulators exert different actions. We used biosensor imaging in live brain slices of dorsomedial striatum to monitor changes in intracellular cAMP at the level of individual MSNs. We observed that the muscarinic agonist oxotremorine decreases cAMP selectively in the MSN subpopulation that also expresses D1 dopamine receptors, an action mediated by the M4 muscarinic receptor. This receptor has a high efficacy on cAMP signaling and can shut down the positive cAMP response induced by dopamine, at acetylcholine concentrations which are consistent with physiological levels. This supports our prediction based on theoretical modeling that acetylcholine could exert a tonic inhibition on striatal cAMP signaling, thus supporting the possibility that a pause in acetylcholine release is required for phasic dopamine to transduce a cAMP signal in D1 MSNs. In vivo experiments with acetylcholinesterase inhibitors donepezil and tacrine, as well as with the positive allosteric modulators of M4 receptor VU0152100 and VU0010010 show that this effect is sufficient to reverse the increased locomotor activity of DAT-knockout mice. This suggests that M4 receptors could be a novel therapeutic target to treat hyperactivity disorders.
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PMID:The high efficacy of muscarinic M4 receptor in D1 medium spiny neurons reverses striatal hyperdopaminergia. 3046 98