Preston, O’Neal, & Talaga (2013), presented the comparison of neural transmission to a telephone switchboard. In many ways, that analogy is accurate since neurotransmitters are essentially messages being sent from one nerve to another. Neurons utilize electrical and chemical stimulation to communicate and ultimately control human behavior.
To understand how transmissions are passed between neural pathways, one must first understand the basic structure of a nerve cell. The main body of the nerve cell or neuron is known as the soma. Its shape differs depending on its specific function but is contains the structures universal to all cells such as the nucleus, mitochondria, and cytoplasm. The axon is a slender tube like structure that emanates from the soma. It is often covered by a myelin sheath which aids in the conduction of information from one neuron to another; known as an action potential. Terminal buttons are the end points of axons which secrete hormones known as neurotransmitters. To do this an action potential must travel down the axon and reach the terminal buttons. The neurotransmitter either excites or inhibits the action potential allowing it to continue or cease its communication with the neighboring neuron. The dendrites of the neighboring neuron receive the transmission from the terminal button across a fluid filled gap called a synapse. The dendrite resembles the branches of a tree and allow the transmission to continue along the neural pathway (Carlson, 2014. & Saladin, 2012).
Neural transmission and action potentials are governed by the balance of positively and negatively charged ions such as sodium, potassium, and chloride. Polarization of the intracellular fluid by salutatory conduction and diffusions allows the transmission of the action potential down the length of the axon until it reaches the terminal buttons. If the action potential is strong enough at the terminal button, synaptic vesicles containing neurotransmitters are able to bind with the presynaptic membrane of the terminal button. This membrane essentially separates the end of the terminal button from the synaptic cleft. The synaptic vesicle is then able to release the neurotransmitter across the intracellular fluid which fills the gap, or synapse, between the terminal button and the opposing dendrite (Carlson, 2014. & Saladin, 2012).
Neurotransmitters are transported from the cell body to the terminal button by sac-like structures called vesicles. The vesicles bind to the membrane of the terminal button ans create tiny opening from which the neurotransmitter is released from the presynaptic neuron. Neurotransmitters are then ale to cross they synapse and bind with receptors on the dendrites of the postsynaptic neuron facilitating communication. While some neurotransmitters bind with the receptor sites on the post synaptic neuron, others are destroyed, or reabsorbed by the terminal button of the presynaptic neuron (Reed, Carlson, Quale, 2016).
Carlson, N. R. (2014). Foundations of behavioral neuroscience (9th ed.). Boston, MA: Pearson. ISBN: 9780205940240.
Preston, J. D., O’Neal, J. H., & Talaga, M. C. (2013). Handbook of clinical psychopharmacology for therapists (7th ed.). Oakland, CA: New Harbinger. ISBN: 9781608826643.
Reed, L., Carlson, L, Quale, S. (2016). Capella University Neurotransmission Retrieved from http://media.capella.edu/course media/PSY7330/animation/transcript.htm1
Saladin. K.S. (2012). Anatomy and Physiology: The Unity of Form and Function. 6th ed. Mcgraw-Hill. New York, NY. ISBN978-0-07-337825-1.