The goal of this chapter is to provide a quick overview about the brain in order to understand the individual, explaining the combination of the nerve cells to achieve human mental capacities, perception, movement, speech and emotion. From the knowledge of the neuronal structure available on this chapter, we are able to understand the neuronal function and the structure of the nervous system, how the connections are made, the impact on emotions and, consequently, its importance in Neuromarketing.
TopNeurons
There are two types of structure of the different cell types in the nervous system: neurons and glial cells. They are broad categories, in which there are many types of cells that differentiate based on their structure, chemistry and function. However, the distinction between neurons and glial cells is important. Although there are many neurons in the human brain (around 100 billion), glial cells outnumber neurons by about 10-fold. In the face of this, it might seem that we should focus our attention on glia to understand the cellular functions of the nervous system. However, neurons are the most important cells for the unique functions of the brain. They are the neurons that perceive modifications in the environment, communicate such modifications to other neurons and command the corporal responses to these sensations. Glia is believed to contribute to brain function primarily by isolating, sustaining, and nourishing neighboring neurons. In fact, the term glia originates from the Greek word used for “glue”, suggesting that the main function of these cells would be to maintain the cohesion of the neural tissue. The simplicity of this view is probably a good indication of the depth of our ignorance about glial function. However, we still believe that the major responsible for the processing of information in the brain are the neurons.
The signal that carries information throughout the nervous system is the potential of action. The action potential is a rapid reversal of this situation, so that for a moment the cytosolic side of the membrane is positively charged relative to the outer side.
The action potentials generated by a cell resemble size and duration and do not decrease as they are conducted along the axon. It should be borne in mind that its frequency and its pattern constitute the code used by the neurons to transfer information from one place to another. In this chapter, we will discuss the mechanisms responsible for the action potential and how it propagates along the axon membrane (Bear, Barry, & Paradiso, 2002).
Initially, specialized ion channels at the sensory nerve terminals allow the entry of positive charges into the axon. If the depolarization reaches the excitation threshold, then action potentials are generated. Action potentials can propagate without decreasing along the sensory nerves because the axonal membrane is excitable and has voltage-sensitive sodium channels. For this information to be processed by the rest of the nervous system, it is necessary that such signals be transmitted to other neurons; for example: motor neurons that control muscle contraction, as well as neurons in the brain and spinal cord that coordinate the reflex response.
As it was necessary to know the neuronal structure to understand neuronal function, the structure of the nervous system must also be known to understand the brain function, so during this chapter some structures and their function will be described. The structures selected according to their importance in Neuromarketing.