claim: Acetylcholine prevents neuromodulation.
evidence: Acetylcholine -LRB- ACh -RRB- is an organic chemical that functions in the brain and body of many types of animals , including humans , as a neurotransmitter -- a chemical released by nerve cells to send signals to other cells .. organic chemical. organic chemical. neurotransmitter. neurotransmitter. Its name is derived from its chemical structure  : it is an ester of acetic acid and choline .. choline. choline. ester. ester. acetic acid. acetic acid. Parts in the body that use or are affected by acetylcholine are referred to as cholinergic .. cholinergic. cholinergic. Substances that interfere with acetylcholine activity are called anticholinergics .. Acetylcholine is the neurotransmitter used at the neuromuscular junction -- in other words , it is the chemical that motor neurons of the nervous system release in order to activate muscles .. neurotransmitter. neurotransmitter. neuromuscular junction. neuromuscular junction. This property means that drugs that affect cholinergic systems can have very dangerous effects ranging from paralysis to convulsions .. cholinergic. cholinergic. Acetylcholine is also used as a neurotransmitter in the autonomic nervous system , both as an internal transmitter for the sympathetic nervous system and as the final product released by the parasympathetic nervous system .. parasympathetic nervous system. parasympathetic nervous system. neurotransmitter. neurotransmitter. autonomic nervous system. autonomic nervous system. sympathetic nervous system. sympathetic nervous system. In the brain , acetylcholine functions as a neurotransmitter and as a neuromodulator .. neurotransmitter. neurotransmitter. neuromodulator. neuromodulator. The brain contains a number of cholinergic areas , each with distinct functions .. cholinergic. cholinergic. They play an important role in arousal , attention , memory and motivation .. Partly because of its muscle-activating function , but also because of its functions in the autonomic nervous system and brain , a large number of important drugs exert their effects by altering cholinergic transmission .. cholinergic. cholinergic. autonomic nervous system. autonomic nervous system. Numerous venoms and toxins produced by plants , animals , and bacteria , as well as chemical nerve agents such as Sarin , cause harm by inactivating or hyperactivating muscles via their influences on the neuromuscular junction .. neuromuscular junction. neuromuscular junction. Sarin. Sarin. Drugs that act on muscarinic acetylcholine receptors , such as atropine , can be poisonous in large quantities , but in smaller doses they are commonly used to treat certain heart conditions and eye problems .. muscarinic. muscarinic acetylcholine receptor. atropine. atropine. Scopolamine , which acts mainly on muscarinic receptors in the brain , can cause delirium and amnesia .. muscarinic. muscarinic acetylcholine receptor. Scopolamine. Hyoscine hydrobromide. The addictive qualities of nicotine derive from its effects on nicotinic acetylcholine receptors in the brain .. nicotinic. nicotinic acetylcholine receptor. nicotine. nicotine