The neuron is made up of the cell body (soma) that contains the nucleus and various appendages that extend from the soma to form branches referred to as dendrites, as well as the axon, which is longer than the dendrites. Neurons lie close to each other but have no direct connection as there is a synapse gap between them. The role of the neurons is to transmit nerve impulses from one individual neuron to the next through the synaptic gap, and this is made possible by the diffusing of chemicals (neurotransmitters) between the two neurons (Evans, 2023). The electrical impulse or action potential activates the release of the neurotransmitters from the synaptic vesicles, after which it binds to the special receptor cells, thereby triggering an impulse in the adjacent neuron. An example is that the sensory neurons carry the relevant impulse from the receptors and transmit this information through the nervous system to the brain, where termination involves translating into sensations such as touch, hearing, or vision.
What are the major components that make up the subcortical structures?
- Thalamus – The thalamus is the largest component of the subcortical structure and is used to relay sensory information that emanates from the periphery and toward the cortex.
- Epithalamus – The component is located on the posterior section of the diencephalon and is the region where the pineal gland that controls the circadian rhythm is located.
- Hypothalamus – Located on the inner anterior of the thalamus, the role of this component is to maintain autonomic and endocrine functions. It controls functions associated with survival and maintaining the body’s homeostasis.
- Hippocampus – The component plays an important role in storing long-term memory as well as spatial navigation.
- Basal ganglia – located in the telencephalon, this part helps control motor functions in humans.
Which component plays a role in learning, memory, and addiction?
The hippocampus is the component associated with learning, memory, and addiction. Through the fimbria that acts as the major output, the hippocampus is able to communicate with different parts of the brain. The connections created form the basis of creating long-term memory, and the injury to this region affects learning and memory. With its role in creating memories, the hippocampus allows for the storage of drug-related cues such as taste, and this is what leads to cravings.
What are the two key neurotransmitters located in the nigra striatal region of the brain that play a major role in motor control?
The two neurotransmitters that play a role in motor control are glutamate and dopamine. Glutamate has several receptors in the central nervous system, and physical exercise is one of the activities that leads to its release (Pal, 2021). In its contribution to motor control, glutamate is responsible for the learning and memory of motor skills in individuals. Damage to the nigra striatal region is one of the contributing factors to the development of Parkinson’s disease due to the loss of memory on motor control. Dopamine is the other neurotransmitter and is associated with the reward for learning and motivation as well as the control of motor skills. Through this neurotransmitter, the individual learns and forms memories on motor skills.
Explain how glial cells function in the central nervous system. Be specific and provide examples.
The glial cells in the central nervous system act as a glue that supports typical brain functions and this facilitates communication between the different neurons while also supporting plasticity and homeostasis. By regulating ion homeostasis, with an example being through the removal of potassium ions from the extracellular space, the glial cells can influence neuronal excitability (Allen & Lyons, 2018). The implication is that the glial cells in the central nervous system have the ability to influence circuit function. Beyond regulating neurotransmission, the glial cells also help in cleaning up the dead neurons, regulating the brain’s metabolism, and synchronizing nerve impulses.
The synapse is an area between two neurons that allows for chemical communication. In 3 or 4 sentences, explain what part of the neurons are communicating with each other and in which direction this communication occur.
In the communication between neurons through the synapse cleft, the axon and axon terminals become the parts that allow for the receipt and processing of incoming information. The communication usually takes place from the presynaptic neuron to the postsynaptic neuron through the facilitation of neurotransmitters that act as chemical messengers (Evans, 2023). The messengers/neurotransmitter molecules move from the presynaptic neuron and bind themselves to the receptor membrane in the postsynaptic cell, and this results in an inhibiting or exciting signal. The excess neurotransmitter that was not passed down to the axon terminals is received by the terminal buttons.
Explain the concept of “neuroplasticity.” Be specific and provide examples.
Neuroplasticity refers to the adaptive functional and structural aspects of the brain, and this implies the ability of the central nervous system to change its functioning in response to extrinsic or intrinsic stimuli. Functional neuroplasticity is dependent on learning and memory, whereby there is an influence on the synaptic relationship between neurons as a result of the intracellular biochemical processes or structural adjustments (Puderbaugh & Emmady, 2023). An example of this is the learning of a new skill that becomes embedded in the brain, thereby allowing the individual to access such functional capacities, and this relates to the element of learning and relearning. Structural neuroplasticity is the ability of the brain to change its neuronal connections due to the constant production and integration of neurons into the central nervous system. An example of this neuroplasticity is through the brain’s ability to change the synaptic strength or the proportion of the grey matter.
Allen, N. J., & Lyons, D. A. (2018). Glia as architects of central nervous system formation and function. Science (New York, N.Y.), 362(6411), 181–185. https://doi.org/10.1126/science.aat0473
Evans, O. (2023). An Easy Guide To Neuron Anatomy With Diagrams. https://www.simplypsychology.org/neuron.html
Pal M. M. (2021). Glutamate: The Master Neurotransmitter and Its Implications in Chronic Stress and Mood Disorders. Frontiers in Human Neuroscience, 15, 1-4. https://doi.org/10.3389/fnhum.2021.722323
Puderbaugh, M., & Emmady, P.D. (2023). Neuroplasticity. Treasure Island (FL): StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK557811/