Neuroscience: Neuron Development

Neuroscience: Neuron Development

The human brain is a complex and extremely vital organ in the sense that it is connected to the body’s nervous system and has a role to play in the coordination and execution of all bodily functions. As such, the growth and development of neurons is an orderly process that takes place in five stages. Part of neuron development is the development of axons and dendrites. The axons take information away from the cell to other cells, whereas the dendrites bring information from other cells into the cell. Expounding on how the dendrites and axons grow and make the right connections can be fascinating

The first stage of neural development is neurogenesis. Being the early stage of neural development, this can be looked at as being the birth of neurons. It takes place during construction of the embryo and in parts of the adult brain. It is defined as being the process by which neurons are produced by the nervous stem cells (Ariana 2019). This process takes place in the subventricular zone of the dentate gyrus in the hippocampus and the subgranular region. The subgranular district is found throughout the walls of the brain’s lateral ventricles. Neurogenesis is followed by cell migration. In simple terms, this process would be defined as being the movement of cells in a particular direction in a coordinated manner so as to get to a specific location. After cell migration comes cell differentiation which is the process by which a cell goes through a transformation that makes it a whole other different cell type. This transformation usually leads to the cell changing into a more specialized cell (Sghirlanzoni, 2015).

Synaptogenesis comes after cell differentiation. As its name suggests, synaptogenesis is the generation of synapses between the neurons. Synaptogenesis is a continuous process that takes place throughout a healthy individual’s life time but also has a flare up in the formative stages of brain development. Everything that has a beginning has an ending. And so does neuron development. The fifth and final stage is the death of the neurons. This is scientifically known as apoptosis. Synaptogenesis is a crucial part of the neuron development process with respect to the meticulous connection and networking of neurons in the nervous system as a whole. It is a lengthy process constituted of synapse formation, maintenance of said synapse, also known as stabilization and the refinement and elimination of the synapses. The refinement and elimination of the synapses is activity dependent (Sghirlanzoni, 2015).

Synaptogenesis extremely regulated and it results in morphologically prominent subcellular structures in the pre- and postsynaptic sites so as to facilitate the transmition of electrical and chemical signals to and from the neurons (Ariana 2019). Synaptic vesicles at the presynaptic siteare concentrated around the electron-dense projections near the synaptic plasma membrane.

The process of synaptogenesis is highly crucial during the period when the nervous system is particularly sensitive to specific environmental stimuli. In the course of this period, there is a certain level of elimination of synapses due to competition for neurotrophins. The elimination of these synapses takes place between early childhood and the commencement of puberty (Ariana, 2019).

In some circles, synaptic alteration in relation to the structural and functional phenotype of the presynaptic terminal is perceived as being the core of neural disease process. With respect to physiology, keeping the release of neurotransmitter in check stands as being an important query. Some changes in the structure and function of nerve terminals are portrayed in neurological diseases. Parkinson’s disease, which is the second most neurodegenerative disease, exhibits degeneration of dopaminergic neurons resulting in dopamine depletion in the brain (Ariana 2019). A few factors and findings show that these elements are connected to presynaptic function and diseases like Huntington disease and amyotrophic lateral sclerosis (ALS), are also involved in synaptic dysfunction (Ariana 2019).

A fast emerging and prominent neurodegenerative disease, Alzheimer’s disease (AD), is characterized by the patient losing his/her memory progressively coupled up with gradual loss of cognitive functions. The patient eventually loses his/her life as a result of the death of brain cells. Quite a number of causative genetic factors including oligomerization of the amyloid beta and mutation of the Tau protein are commonly associated with the causation of AD (Sghirlanzoni, 2015)

Despite the fact that these genetic factors have been identified and characterized, a few conspiracies are still surfacing and are still quite evasive.

References

Angelo Sghirlanzoni. (2015). Prognosis o neurological diseases. Springer. https://www.vitalsource.com

Armin Ariana. (2019). Neurological diseases. Thieme medical publishers