Psychobiology: Advantages of Chemical Synapses in Nervous System

This discussion post explores the advantages of chemical synapses, which are specialized junctions for signal transmission in the nervous system. The primary advantages highlighted are signal amplification and modulation. Chemical synapses, unlike electrical synapses, allow for amplification, as a single presynaptic neuron can influence multiple muscle cells. They also enable modulation, allowing for changes in synaptic transmission efficacy through mechanisms such as calcium conductance and neurotransmitter binding. The post further discusses the unidirectional nature of chemical synapses and their role in both excitatory and inhibitory signals, facilitating complex nervous system regulation. Chemical synapses are predominant in higher organisms due to their complex functions, including the presence of auto receptors and the involvement of the SNARE protein in neurotransmitter release. These features enable the regulation of diverse bodily functions, making chemical synapses crucial for advanced neural communication.

Running head: CHEMICAL SYNAPSES
Chemical Synapses
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The advantages of chemical synapses
Chemical synapses are specialised junctional area through which cells of the nervous
system signals transmits signals from one neurons to another and also from non-neuronal
cells such as glands and muscles (Andreae & Burrone, 2018). The main advantages of
chemical synaptic transmission over electrical transmission are amplification and modulation.
The amplification signal is very abundant in the nerve-muscle junctions (Sheffler &
Pillarisetty, 2019). An action potential in an only presynaptic motor neuron helps in the
contraction of numerous muscle cells since signalling molecules are essential to stimulate
contraction. The quantity of electrical signal that is present in the presynaptic terminal is not
satisfactory enough to provide effect on the postsynaptic cells (Pereda, 2014). The chemical
synapse has is complex because it requires amplification to generate adequate impulse. The
advantage of this is the part of presynaptic terminal is small which is helpful in processing the
information within the neuron. The next advantage of this chemical synaptic transmission is
modulation. It is the ability of changing the efficacy of the synaptic transmission. The sites of
this modulation can be increase in calcium conductance that occurs in the presynaptic
terminal, the biding capacity of the neurotransmitters to the receptors of postsynaptic
neurons. The kinetics of channel opening and closing at the nerve junctions (Elegheert et al.,
2017). Other advantage of this chemical transmission is that the pathway is unidirectional that
is- neurotransmitters are released by the neurons into the synaptic cleft, which is further
realised by the exocytosis in the synaptic cleft. The signals are also different in presynaptic
junction and post synaptic junction. The transmission provides an extra regulation nervous
system as the presynaptic region either activates or inhibits the cells of the postsynaptic
region (Jewett & Sharma, 2019). The chemical synapses has both the types of signals that is
excitatory or action potential caused due to the neurotransmitters that effects the postsynaptic

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membrane where the other synapse uses the neurotransmitters to make the postsynaptic
region depolarise. It facilitates the nerve cells to work by both the types of synapses.
Chemical synapses are predominant in higher organism
The chemical synapses are most common type of synapse found in the vertebrates. It
is associated with the morphological functions as well because higher organism has much
more developed brain and spinal cord in sensing the neurotransmitters. The inhibitory and the
excitatory mechanism are much strong in the higher organisms. The chemical synapses has
its auto receptors which senses the excess amount of neuron transmitters and thus maintains a
normal output or responses. The response is also delayed in this case for the occurrence of
molecular activity at the postsynaptic membrane that results in the production of action
potential followed by neurotransmitter bindings. This system is also a calcium dependent
system. The calcium triggers that cascade which results in the fusing of presynaptic
membrane with the postsynaptic membrane with release of transmission in the synaptic cleft
(Williams & Smith, 2018). The SNARE protein is involved in this pathway. The
neurotransmitter through the pathway of chemical transmitters regulates the variety of
functions in the body including control of heart rate, memory, sleep, psychological responses
and thus choses this pathway over electrical response (Maldonado & Alsayouri, 2019).

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References
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and circuit development. Journal of neuroscience research, 96(3), 354–359.
https://doi.org/10.1002/jnr.24154
Elegheert, J., Cvetkovska, V., Clayton, A. J., Heroven, C., Vennekens, K. M., Smukowski, S.
N., Regan, M. C., Jia, W., Smith, A. C., Furukawa, H., Savas, J. N., de Wit, J.,
Begbie, J., Craig, A. M., & Aricescu, A. R. (2017). Structural Mechanism for
Modulation of Synaptic Neuroligin-Neurexin Signaling by MDGA
Proteins. Neuron, 95(4), 896–913.e10. https://doi.org/10.1016/j.neuron.2017.07.040
Jewett, B. E., & Sharma, S. (2019). Physiology, GABA. PMID: 30020683
Maldonado, K. A., & Alsayouri, K. (2019). Physiology, Brain. In StatPearls [Internet].
StatPearls Publishing.
Pereda A. E. (2014). Electrical synapses and their functional interactions with chemical
synapses. Nature reviews. Neuroscience, 15(4), 250–263.
https://doi.org/10.1038/nrn3708
Sheffler, Z. M., & Pillarisetty, L. S. (2019). Physiology, Neurotransmitters. In StatPearls
[Internet]. StatPearls Publishing.
Williams, C. L., & Smith, S. M. (2018). Calcium dependence of spontaneous
neurotransmitter release. Journal of neuroscience research, 96(3), 335–347.
https://doi.org/10.1002/jnr.24116

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