We are truly living in the golden age of neuroscience. Today, with the help of sophisticated brain scans and diligent scientific research, humans are consistently inching closer to solving the profound mystery of the human psyche. We are able to ascertain the neural bases of craving, desire, internet addiction, laughter, reading, and war. Because of neurological breakthroughs, we have begun to question if some criminal acts are committed by free volition and not because of neurochemical or neuroanatomical imbalance, lesion, or tumor and are beginning to move towards better rehabilitation, and not punishment, for criminals. By the power of neuroplasticity, people have reconfigured their brains with great success in order to compensate for a lost sense or body part. Researchers in this field are on the forefront of finding a cure to Alzheimer’s and other tragic neurological diseases. As we embark upon the third decade of the 21st century, our world will see a greater emergence of the salience of neurobiology, and it would be beneficial to have a basic understanding of neuroscience. Thus, for my next couple of articles, I will be guiding you through this wonderful science.
So what exactly is neuroscience? Neuroscience is the study of how the nervous system develops, its structure, and what it does. (1). The nervous system is the system in the body that controls internal functions of the body and receives, interprets, and responds to stimuli. (2) It is basically the body’s speedy communication highway. The nervous system has two major divisions: the Central Nervous System, comprised of the brain and spinal cord, and the Peripheral Nervous System, which consists of nerves and sensory organs. In a later article, I’ll discuss the nervous system in its entirety, but for now, we are going to focus on one of the most elementary aspects of the nervous system: the neuron.
Everyone remembers the levels of the human body from middle school biology: (atom, molecule), cell, tissue, organ, organ system, and organism. A neuron is a nerve cell with many complex parts. The dendrites, or the dendritic tree, “listen” and receive information in the form of neurotransmitters from another neuron. This chemical signal either alerts the neuron to fire or not to fire. To fire or not to fire, what is the question? The dendritic tree transmits that electrochemical impulse to the cell body, or soma. In the soma, processing occurs. If the neuron decides to fire, the neural firing, also known as the action potential, is conducted by the axon, specifically the axon hillock. The axon hillock is the bridge between the cell body and the axon that has gates that would allow for sodium ions to flow into the neuron in the event of an action potential. The axon is coated by myelin and glial cells, which insulate the axon and allow for a quick neural communication. The branches at the end of the cell, also known as the axon terminal, exchange with the dendrites of the postsynaptic neuron. What’s the currency? Neurotransmitters.
A neurotransmitter is a chemical that is released from a nerve cell which thereby transmits an impulse from a nerve cell to another nerve, muscle, organ, or other tissue. (3) It is said that dendrites listen, while the synapses talk. Neurons do not actually touch, there is a small gap between them known as the synapse. When neurotransmitters are dispensed into the synaptic gap, there are various possible scenarios: the neurotransmitters are absorbed by the postsynaptic neuron, are broken down by enzymes, or experience reuptake back into the presynaptic neuron. In my next article, we will dive into the neuron’s action potential and various neurotransmitters. For now, you know the parts of the neuron! The future is looking bright.
References and Footnotes: