How Neurons in Central Nervous System Communicate - Essay Example

?HOW NEURONS IN THE CENTRAL NERVOUS SYSTEM COMMUNICATE, AND HOW THIS HAS HELPED IN UNDERSTANDING HUMAN BEHAVIOUR by of the Name of the Professor Name of the School City, State 18 December, 2012 How Neurons in the Central Nervous System Communicate Neurons are specialized cells in the body which perform different roles in the nervous system. They all have the same body structure, but tend to vary in shape and sizes, due to the length of their axon, and the task they handle. Neurons within the nervous system come in three forms; the afferent, efferent, and interneurons. The nervous system is split into the central and peripheral nervous system. The Peripheral Nervous System (PNS) depends on the afferent neurons, to deliver messages they receive from the sensory receptor to the brain, and the efferent neurons take the message of reaction from the brain, into the areas in the body. The central nervous system, which is made up of the brain and the spinal cord, depends on the interneurons, which consist 97 percent of the cells, besides beginning and ending their role within the system (Collins, 1989, p. 29). In the Central Nervous System (CNS), there are billions of neurons each with chemical and electrical capacities, to facilitate communication via electrochemical means. A neuron is the basic unit of the nervous system, and functions through the distinguished body parts, the receiving end (dendrites) and terminal buttons separated by the axon. (Communication in the nervous System, n.d.) The multiple numbers of the neurons form a neural net, due to the interconnections from one neuron to the other, which facilitate the electrochemical communication. The neuron picks up some chemicals referred to as neurotransmitters through its dendrites from the synapse (the space between the nerve cells), after being released by another neuron. “Neurotransmitters are chemical messengers that convey information in the form of an electrically charged neuron to neuron and from brain structure to brain structure” (Levinson, 2002, p. 111). The electrical signal generated in the dendrites depends on the effect of the neurotransmitters, which can be either positive or negation. Suppose sufficient excitatory (++) chemicals enter the dendrites, they cause the neuron to fire, as the positive ions move into the cell surpassing the resting potential of the cell, and transmitting an electric signal through the axon to the terminal buttons, to cause an action potential. An action potential is an electric pulse, which moves down the axon, to the terminal buttons until it reaches the synaptic gap, which lead to neurotransmitters release (Animatlab.com, 2006). The charge of the inside neuron fluid is negative, while the outside tends to be neutral due to the presence of both ++ and -- ions. Hence, if the dendrites pick the inhibitory (--) chemicals, chances of causing a fire or an action potential are few, since it would be supplementing the negativity of the inside fluid than the resting potential. The neuron electrical signals make their way down the axon, causing a release of the neurotransmitters at the terminal buttons, into the synapse from which the dendrites of a neighbouring neuron would pick. Even if the interneurons make up 97 percent of the CNS, the afferent and the efferent neurons play quite a huge task in sending signals from the environment into the brain for processing, and from the brain into the body parts respectively. The spinal cord as part of the CNS makes the communication easier, as it contains the all the three types of neurons. The interconnection capability allows the interneurons in the spine to produce a response of an emergency situation that does have to involve the brain, hence allowing the spinal cord to control fast reflexes. Basically, communication for the neurons in CNS occurs at the synapses, through chemical and electrical processes. Understanding Human Behaviour Human behaviour is a result of the communication mechanism within the neurons. At times, the level of amount of the neurotransmitters picked by the dendrites may have a negative impact on the human neurological and psychological health. The neurotransmitters have the power to affect memory, mood, appetite control, developmental delays, and the wellbeing in an individual among others. Although important, neural transmitters such as, GABA (gamma- aminobutyric acid), as an inhibitory chemical causes eating, sleeping and convulsive disorders when picked up in abnormal levels, low levels of serotonin and norepinepherine is associated with depression. High level of serotonin on the other hand is associated with childhood autism. Parkinson’s disease and Alzheimer's disease are associated with degeneration of cells, which produce dopamine, loss of brain that produce acetylcholine respectively, and generally low levels of excitatory neurotransmitters lead to fatigue and lack of focus, while the opposite cause anxiety and agitation (Wells, 2012). In assessing a reflex behaviour, consider an individual touching a hot object unexpectedly. The sensory nerve takes the message instantly to the spinal cord; the interneurons employ their power to communicate shortly, without necessarily involving the brain and relaying the message back through the motor neurons to the muscles, and organs affected. According to Collins, “the communication between these specialized neurons determines the potential of our higher thinking capabilities, as well as providing us with memories, thoughts and emotions” (1989, p. 29). The sensory neurons convey the message to the interneurons through chemical and electrical processes to cause an action potential facilitating interneurons communication, which in the spinal cord sends a signal of reaction back to the motor neuron. This is why an individual is quick to retrieve the hand as the reflex behaviour. Neurotransmitters released in the synaptic gap are either absorbed, or destroyed, or diffused out. Consider another case involving dopamine neurotransmitters; their purpose may fail to come out clearly due to interference by hormonal actions. The sensory nerves detect the smell and send a signal to the interneurons, which triggers dopamine release as a brain reward system. Such environmental stimulations are nicotine and physical exercise such as running. The dopamine causes a feeling of pleasure and relaxation into the body’s organs and muscles through the motor neurons. According to Levinson, “dopamine operates by setting into motion a biological process that gives rise to an emotional response that motivates behaviour” (2002, p. 111). Suppose the dopamine released into the synaptic gap is blocked or replaced due to another chemical interference, the messages are altered affecting the cognition, psychological system and behaviour in the general. References Animatlab.com, 2006. Neuron Basics. [online] Available at: [Accessed 18 December 2012]. Collins, K., 1989. Anatomy Academy Book 3: Nervous System, Senses and Glands, Book 3. Austin, TX: Prufrock Press Inc. [Communication in the nervous System] n.d. [image online] Available at: < http://cla.calpoly.edu/~cslem/101/4-B.html#communication%20specialists> [Accessed 18 December 2012]. Levinson, D., ed. 2002. Encyclopedia of Crime and Punishment, Volume 1. London: Sage publications. Wells, W., 2012. The Brain Game - Balancing Neuro-Transmitters and Hormones. [online]Available at: [Accessed 18 December 2012]. Read More