Acetylcholine

<p ><b>Acetylcholine</b>&nbsp;(often abbreviated&nbsp;<b>ACh</b>) is an&nbsp;<a href="http://en.wikipedia.org/wiki/Organic" title="Organic" >organic</a>,&nbsp;<a href="http://en.wikipedia.org/wiki/Polyatomic_ion" title="Polyatomic ion" >polyatomic ion</a>&nbsp;that acts as a&nbsp;<a href="http://en.wikipedia.org/wiki/Neurotransmitter" title="Neurotransmitter" >neurotransmitter</a>&nbsp;in both the&nbsp;<a href="http://en.wikipedia.org/wiki/Peripheral_nervous_system" title="Peripheral nervous system" >peripheral nervous system</a>&nbsp;(PNS) and&nbsp;<a href="http://en.wikipedia.org/wiki/Central_nervous_system" title="Central nervous system" >central nervous system</a>&nbsp;(CNS) in many organisms including&nbsp;<a href="http://en.wikipedia.org/wiki/Homo_sapiens" title="Homo sapiens" class="mw-redirect" >humans</a>.&nbsp;</p>

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Acetylcholine is one of many neurotransmitters in the&nbsp;<a href="http://en.wikipedia.org/wiki/Autonomic_nervous_system" title="Autonomic nervous system" >autonomic nervous system</a>&nbsp;(ANS) and the only neurotransmitter used in the motor division of the&nbsp;<a href="http://en.wikipedia.org/wiki/Somatic_nervous_system" title="Somatic nervous system" >somatic nervous system</a>&nbsp;(sensory neurons use&nbsp;<a href="http://en.wikipedia.org/wiki/Glutamate" title="Glutamate" class="mw-redirect" >glutamate</a>&nbsp;and various peptides at their synapses). Acetylcholine is also the principal neurotransmitter in all&nbsp;<a href="http://en.wikipedia.org/wiki/Autonomic_ganglia" title="Autonomic ganglia" class="mw-redirect" >autonomic ganglia</a>.</p>

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In cardiac tissue acetylcholine neurotransmission has an inhibitory effect, which lowers heart rate. However, acetylcholine also behaves as an excitatory neurotransmitter at neuromuscular junctions in skeletal muscle.<sup id="cite_ref-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Acetylcholine#cite_note-0" >[1]</a></sup>

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<h5 >Alzheimer's disease</h5>

<p >Since α4β2 AchRs are reduced in Alzheimer's disease, drugs that&nbsp;<a href="http://en.wikipedia.org/wiki/Acetylcholinesterase_inhibitor" title="Acetylcholinesterase inhibitor" >inhibit acetylcholinesterase</a>,&nbsp;

e.g.&nbsp;<a href="http://en.wikipedia.org/wiki/Galantamine_hydrobromide" title="Galantamine hydrobromide" class="mw-redirect" >galantamine hydrobromide</a>&nbsp;(a competitive and reversible cholinesterase inhibitor), are commonly used in its treatment.</p>