Neurons are one of the cells that generate the most activity in the body, so it is difficult to capture their processes even using high-resolution technology. However, its identification was possible more than a century ago, during the year 1873, due to the practices carried out by the Italian anatomist named Camillo Golgi .
By means of an experiment carried out with silver salts, it was observed that these stained the neurons of a dark coloration. Thus, its visualization could be facilitated, being able to understand its structure; it was even possible to make classifications according to the different types. Golgi staining is still used today, it is useful for studying neuronal pathologies.
What is a neuron?
The word neuron has its origin in a Greek term which was “neûron”, this is translated as nerve. It is used to refer to a type of cell that belongs to the central nervous system, it has the ability to capture and decode information from chemical and electrical stimuli .
Neurons control voluntary and involuntary functions in the body. Its function is to transmit information through impulses. They have a plasma membrane which has electrical excitability, thus there is reception of stimuli and conduction of nerve impulses.
The neural network is made up of independent communication networks , which in turn communicate with each other . Thus each one is in charge of developing specific functions, this information is transmitted to different parts of the body.
The communication that is generated between the neurons themselves is usually described, but these nerve impulses also reach the muscle fibers that connect with the motor plate. For this reason, neurons are responsible for some essential functions such as the pumping of the heart muscle. They communicate with cell types like nerve, glandular, and muscle cells.
The area of reception of the impulses is called dendrite, and the area of emission is called axon or neurite. Nerve impulses are nothing more than electrical signals, and these pass through the structure of the neuron. The connection that is made with other neurons or fibers is called a synapse, a chemical discharge is generated that also generates the electrical current that will be conducted through the membrane of the emitting cell.
When an impulse reaches the end of the axon, the neuron subsequently begins to secrete a protein ( neurotransmitters ). These substances are responsible for inhibiting or exciting the action that must be produced in the neuron.
What are the characteristics of neurons?
The main characteristic of neurons is their electrical excitability . This means that they have the ability to transmit nerve impulses through the central nervous system. Other features are mentioned below:
- Approximately the human brain of an adult has 100 billion neurons.
- The only nerve cells are neurons, but other types of cells such as glandular and muscle cells are also part of the nervous system .
- Like other types of cells, neurons are covered by a plasma membrane . These are responsible for separating the inside from the outside.
- Its main function is to transmit nerve impulses to other cells. The human brain is made up of an abundance of these cells and in this way information can be processed faster per second.
- They are differentiated cells, which means that they cannot divide or reproduce. Therefore, when they deteriorate and die they cannot be replaced.
- Neurons do not usually reproduce , however it has been detected that these can be created from stem and progenitor cells. This means that there are cells located in the brain that can reproduce in a process called neurogenesis .
- The morphological characteristics of neurons are typical. The body called soma has several short extensions; through them impulses are transmitted to the cell soma. The longest processes, called axons , are those that conduct these impulses
How is its structure?
Neurons, like other types of cells, show a structure defined by parts that fulfill specific functions. Each of them interacts with each other, generating the activities for which they are essential. Each of the 4 parts of the structure is described below :
- The nucleus is located in the center of the neuronal cell, it is easy to visualize and all of the genetic information is concentrated in it . The nucleoli are also located in it, these are substances that have DNA. There is also an accumulation of proteins that are essential for the activity of neurons, they are stored in a sphere whose name is Cajal.
- The perikaryon , also known by the name of soma, is the body of the neuron. Inside it there are organelles where the process of protein synthesis takes place , this is the case of ribosomes. They are supramolecular compounds made up of proteins, mitochondria and RNA, this is how energy is supplied to cellular activity.
Also within this body there are granules called Nissl, they are responsible for accumulating rough endoplasmic tissue; that serves to transport and synthesize protein. In the cell body the Golgi apparatus is located, it is responsible for the addition of carbohydrates to proteins.
- The dendrites are identifiable by their form of branches whose origin is from the precarion. They are responsible for receiving stimuli and also for cell feeding, the establishment of neuronal connections depends on them . They are also made up of organelles that are part of the synapse process.
- The axon is an extension of the neuron, this is where nerve impulses are controlled throughout the entire body system. This is done through dendrites , making connections with other neurons. In order for them to transmit these impulses quickly, a coating is required, this is because it is the only way to maintain the electrical charge.
Most neurons are covered by myelin, this substance is produced by a cell called Schwann. The neurolemocytes or Schwann cells completely cover the axons, leaving spaces between them whose name is Ranvier’s nodes. Their function is to ensure that the electrical impulse can travel at a higher speed.
Neurons fulfill several functions, the main one is to transmit information such as nerve impulses to other cells. Thus all parts of the body are instructed to perform activities such as muscle movements and breathing . This is also how the perception of pain from blows is generated.
The reception , processing and sending of information is possible through the synapse , this in turn can be done in two different ways:
- The electrical synapse consists of the transmission of ions from one neuron like this to another, through protein connections. This is assigned the name of gap or cleft junctions, the electrical impulse is transmitted without dependence on a neurotransmitter. Compared to a chemical synapse, in this case it is faster because it is bidirectional.
- The chemical synapse consists of the release of neurons that are receptors for neurotransmitters. These are small molecules, which are responsible for transferring information between cells. Examples of this type are dopamine, serotonin, endorphin and acetylcholine among others.
Why is your study important for psychology?
Neurons are important cells for proper neuronal functioning and also in the different body systems. They are part of several essential functions , this is the case of the process of safeguarding short-term memory and learning. There is a type of neurons called Cholinergic that are responsible for these actions.
They are the messenger cells that help transmit information to the brain. Studies in psychology applied to this subject have been focused on understanding how the work of neurons influences various mental functions.
It is known that at the muscular level they act as stimuli that cause contractions and movements . By not being part of these processes, you could run the risk of suffering respiratory or cardiac arrest, this is because the organs function depending on these stimuli.
The same happens with processes such as memory formation in the hippocampus. When there is a neuronal problem in this area, it is usually associated with diseases such as Alzheimer’s , in some cases patients suffer from memory loss completely.
The human brain is mainly made up of neurons, but there are also other complementary cells. Each of the neurons responds to impulses, triggering an electrochemical process that spreads throughout the neural network. Long distances are traveled and each part will be interacting with the brain, then the neurons act in groups and also in isolation.
Alexa Clark specializes in Cognitive Behavioral Therapy. She has experience in listening and welcoming in Individual Therapy and Couples Therapy. It meets demands such as generalized anxiety, professional, love and family conflicts, stress, depression, sexual dysfunction, grief, and adolescents from 15 years of age. Over the years, She felt the need to conduct the psychotherapy sessions with subtlety since She understands that the psychologist acts as a facilitator of self-understanding and self-acceptance, valuing each person's respect, uniqueness, and acceptance.