Acetylcholine: Neurotransmitter's Role in Nervous System Explained

This assignment provides a comprehensive overview of Acetylcholine, a widely known neurotransmitter, detailing its discovery and function within both the central and peripheral nervous systems. It explores the role of Acetylcholine in muscle movement, highlighting its impact on skeletal and cardiac muscles, and explains how it facilitates muscle contraction and relaxation. Additionally, the assignment delves into Acetylcholine's involvement in the central nervous system, discussing its effects on learning, short-term memory, and its influence during wakefulness and REM sleep. The paper emphasizes the importance of cholinergic neurons and their communication paths, supported by references to key research in the field, offering a detailed understanding of Acetylcholine's significance in the autonomic nervous system and overall neurological function.

Acetylcholine, which is the most widely known and spread neurotransmitter, was
invented in 1914 by Hallett Dale and the existence later confirmed by Otto Loewi. Acetylcholine
is a chemical message that aids in the transmission of signals throughout the nerve synapse and
can be found both in the central nervous systems and the peripheral systems. Neurotransmitters
are the known messengers of the brain and have their origin from within the body. They carry
messages from a neuron to another. Cholinergic neurons are neurons which use acetylcholine in
the transmission of signals and such neurons use synapses as the communication path (Kumar
2015, p. 615).
Acetylcholine in the Peripheral nervous system
Acetylcholine acts as neurotransmitter found at the junction of the neuro muscles found
between the skeletal muscles and the motor nerve. Here it acts as an effective stimulant of the
movement of the muscles. The receptors of acetylcholine on the muscles accept acetylcholine
thereby causing a contraction in the skeletal muscles. In the combination of acetylcholine
receptors with acetylcholine, the gated ligand sodium fees found in the cell membrane is
unlocked thereby resulting in the contraction of the skeletal muscles (Robertson 2014, p. 715).
The unlocked sodium ions then move into the cell of the muscle triggering movements
that end up generating tightening of the muscles. Acetylcholine receptors are also responsible for
the relaxation of the muscles of the heart (Schmidt-Nielsen 2013, p. 547). In as much as
acetylcholine triggering the tightening of skeletal muscles, its operation is through a diverse
receptor form for example muscarinic thereby hampering the tightening of the strands of the
cardiac muscles. This prevents contraction of the muscles of the heart and instead promotes
relaxation.

Acetylcholine in the Central Nervous System
Acetylcholine is found in interneurons in the central nervous system in both green and
orange cell clusters. It is also found to be existing in cholinergic pathways with long axons.
Acetylcholine has effects on learning and short-term memory for the central nervous system. It
achieves this through synaptic plasticity which is the ability of acetylcholine to change the
connection strength of neurons (Kumar 2015, p. 301).
It is also worth noting the cholinoceptive projection derived from the Meynert basalis
nucleus found in the forebrain neocortex and the linked structures of the limb. Most of the
subcortical areas are innerved by neurons from the Ponto-mesencephalic (Koutsilieri 2010, p.
198). Acetylcholine is tasked with the increase in the sensitivity of the sensors when the body is
awakened and in cases of sustained awareness. It has been considered to as one of the essential
inducers of the rapid movement of the eyes or REM when sleeping.
In summary, acetylcholine which is commonly abbreviated as Ach serves very important
roles both in the peripheral nervous system and central nervous system. Ach is classified as one
of the numerous neurotransmitters in the autonomic nervous system. Acetylcholine is a
fundamental neurotransmitter in the whole autonomic ganglia.

References
Koutsilieri, E 2010, Neuropsychiatric Disorders: An Integrative Approach, 4th edn, Springer,
London.
Kumar, S 2015, Recent Trends in the Acetylcholinesterase System, 3rd edn, IOS Press, Oxford.
Robertson, D 2014, Primer on the Autonomic Nervous System, 5th edn, Academic Press,
London.
Root, WS 2013, The Nervous System: Autonomic Nervous System Drugs, 4th edn, Elsevier, New
York.
Schmidt-Nielsen, K 2013, Animal Physiology: Adaptation and Environment, 3rd edn, Cambridge
University Press, Cambridge.