Memory Storage Requires Neuronal Remodeling
In introducing the term synapse, a researcher by the name of Charles Sherrington speculated that synaptic alterations might be the basis of learning and memory storage, anticipating an area of research that to this day is one of the most intensive efforts in all of neuroscience (Alberini, 2011). Modern ideas about neural plasticity have their origins in the theories of Donald Hebb, who proposed that when a pre-synaptic and a post-synaptic neuron are repeatedly activated together, the synaptic connection between them will become stronger and more stable in order to form long term memories. Ensembles of neurons, or cell assemblies, linked via synchronized activity of these Hebbian synapses, could then act together to store long-term memory traces. It was this idea that would eventually be confirmed in various brain tissues, including the hippocampus. Most current theories of the cellular basis of learning and memory storage focus on plasticity of the structure and physiological functioning of synapses (Bays, Wu, & Husain, 2011).
Synaptic changes that may store information can be measured physiologically. The changes could be pre-synaptic, post-synaptic, or both. Such changes include greater release of neurotransmitter molecules and/or greater effects because the receptor molecules become more numerous or more sensitive. The result of such changes would be an increase in the size of the post-synaptic potential. Changes in the rate of the inactivation of the transmitter, through reuptake or enzymatic degradation, could produce a similar effect (Alberini, 2011).
Synaptic activity could also be modulated by inputs from other neurons causing extra depolarization or hyper polarization...
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A prosthetic is an artificial device that replaces a missing body part lost through trauma, disease, or congenital conditions. Prosthetics are becoming revolutionized to encourage amputees to pursue their highest ambitions. The technologies are progressing in prosthetics to make amputees lives more functional and the prosthetics life like.
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The brain is part of the central nervous system, which consists of neurons and glia. Neurons which are the excitable nerve cells of the nervous system that conduct electrical impulses, or signals, that serve as communication between the brain, sensory receptors, muscles, and spinal cord. In order to achieve rapid communication over a long distance, neurons have developed a special ability for sending electrical signals, called action potentials, along axons. The way in which the cell body of a neuron communicates with its own terminals via the axon is called conduction. In order for conduction to occur, an action potential which is an electrical signal that occurs in a neuron due to ions moving across the neuronal membrane which results in depolarization of a neuron, is to be generated near the cell body area of the axon. Wh...
The study of neurobiology has long involved the actions and interactions among neurons and their synapses. Changes in concentrations of various ions carry impulses to and from the central nervous system and are responsible for all the information processed by the nervous system as a whole. This has been the prominent theory for many years, but, now, there is a new one to be reckoned with; the Quantum Brain Theory (QBT). Like many new theories, the QBT has merits and flaws. Many people are wholeheartedly sold on it; however, this vigor might be uncalled for. Nevertheless, this could prove to be a valid and surprisingly accurate theory of brain function.
In “The Brain on Trial”, David Eagleman argues that the justice system needs to change due to advances in neuroscience. Eagleman uses a variety of rhetorical strategies to present his viewpoint. The most important one is his use of examples and reasoning. Therefore, by using mostly examples and reasoning, along with direct address to the readers, Eagleman is able to argue that the legal system has to modify its sentencing policies in accordance with advances in neuroscience due to the increase in the amount of accused and/or convicted people who have been found to have harbored some kind of brain disease or damage. In other words, their actions were not entirely voluntary.
The human brain and that of any species contains nerve cells that link to each other connecting the brain and spinal cord to the rest of the body (Johnson, 2013). These nerve cells are neurons that connected through synapses in a web-like fashion forming neural networks (Coon & Mitterer, 2001). Neural networks make generation and transmission of action potentials (known as electrical impulses) possible along neurons. An action potential is generated across an axon hillock of a nerve cell and is propagated along the axon by the opening of voltage-gated ion channels one after the other causing positive ions to flow in and out the axon (Johnson, 2013).
According to Berlucci and Butchel (2009), plasticity describes an alteration in neural organization. Plasticity may be to blame for several types of behavior changes both short-term and permanent, such as growth, learning, injury, aging, and adaption to various settings. While several authors have attempted to more appropriately define the term, researchers are inclined to relate the theory to essentially any deviation found within the nervous system. Today, the method of behavior change can mostly likely be described by the alteration of synaptic transmission amongst neurons.
Memory refers to storage, for example, our thoughts, knowledge, past experience, retention and recalled information is part of our cognitive mapping. It depends on a person state of mind that’s specific information varies to the content of the information itself. Needless to say, information that is considered interesting, or exciting seems to be better remembered than information that is boring or uninterested. Usually, if information has failed adequately store than the memory can normally result as failure as well. Which means if the storage of information fails to retain (forgetting) or if failure to retrieve the person’s memory fails altogether. The neurons produce activity in other neurons which overtime will be strengthened, that is known to be located inside a person’s long-term potentiation. (Meyers,
First, the Electrical synapse relies on having two cells spanning across two membranes and the synaptic cleft between them (Shepard and Hanson, 2014, para. 2). Overall, the purpose of the Electrical synapse for the nervous system is for the synapse to carry out impulses and reflexes. On the contrary, the neuronal structure of the Synapse’s Chemical synapse involves the role of neurotransmitters in the nervous system. Located between the nerve cells, the gland cells, and the muscle cells, the Chemical synapse allows neurons for the CNS to develop interconnected neutral circuits. According to Davis (2007), “Interconnected logical computations that underlie perception and thought” (p.17). Generally, regarding the Chemical synapse’s role in the nervous system, this classification of the Synapse has a valuable role on how drugs affect the nervous system actions on synapses. As a result, the activity of the neurotransmitters becomes the key contributor for the Chemical synapse to effectively process drugs in the nervous system and throughout the human autonomy. Defines as a chemical released across the Synapse of a neuron, neurotransmitters manipulates the body to believe the drugs are neurotransmitters as well (Davis, 2007, p. 19). Significantly, the role of drugs in the human body help prevents the obliteration of neurotransmitters in the nervous system (Davis, 2007, p. 19).
The process of memorization starts at birth with the development of cells and extends throughout the lifetime through the effects of life experiences and stimulants. Like the rest of the body, the brain is made up of cells. These brain cells are different, more specialized cells. (Sprenger 1). Two major brain cells are the neurons- the nerve cells- and the glial cells which work as the ‘glue’ of the neurons. At birth, the brain contains approximately 100 billion neurons. Although that number remains constant over time, these cells can lose their function if not exercised properly in a process called “neutral pruning”. Learning is defined as “two neurons communicating with each other”. A neuron has learned when it has made a connection with another neuron (Sprenger 2).
The neuron has two important structures called the dendrite and axon, also called nerve fibers. The dendrites are like tentacles that sprout from the cell and the axon is one long extension of the cell. The dendrites receive signals from other neurons, while the axon sends impulses to other neurons. Axons can extend to more than a meter long. Average sized neurons have hundreds of dendrites; therefore it can receive thousands of signals simultaneously from other neurons. The neuron sends impulses by connection the axon to the dendrites of another nerve cell. The synapse is a gap between the axon and the adjacent neuron, which is where data is transmitted from one neuron to another. The neuron is negatively charged and it bathes in fluids that contain positively charged potassium and sodium ions. The membrane of the neuron holds negatively charged protein molecules. The neuron has pores called ion channels to allow sodium ions to pass into the membrane, but prevent the protein molecules from escaping (potassium ions can freely pass through the membrane since the ion channels mostly restrict sodium ions). When a neuron is stimulated (not at rest), the pores open and the sodium ions rush in because of its attraction to the negatively charged protein molecules, which makes the cell positively charged. As a result, potential energy is released and the neurons send electrical impulses through the axon until the impulse reaches the synapse of any neurons near it.
Steinbock, Bonnie, Alex J. London, and John D. Arras. "’Rights- Based’ Approaches." Ethical Issues in Modern Medicine. Contemporary Readings in Bioethics. 8th ed. New York: McGraw-Hill, 2013. 23. Print.
In their inactive state neurons have a negative potential, called the resting membrane potential. Action potentials changes the transmembrane potential from negative to positive. Action potentials are carried along axons, and are the basis for "information transportation" from one cell in the nervous system to another. Other types of electrical signals are possible, but we'll focus on action potentials. These electrical signals arise from ion fluxes produced by nerve cell membranes that are selectively permeable to different ions.
During early childhood, there is a huge proliferation of connections between neurons, usually peaking around the age of two. The adolescent brain then cuts down the amount of connections, deciding which ones are important to keep and which can be let go. While there are various theories as to the molecular mechanisms by which pruning actually occurs, most agree that pruning is primarily carried out by a very motile form of glial cell, called microglia [1], and pre-programmed cell death (apoptosis). These microglia are thought to remove cellular debris and perform surveillance during the healing process of an injured brain, but in the healthy, developing brain they have a possibly more important function. If a synapse receives little activity, it is weakened and eventually deleted by microglia and other glial cells through a process called long-term depotentiation (LTD). After the synapse has been removed, the space and resources that it once used are taken by other synapses. These synapses are strengthened by long-term potentiation (LTP). These processes and various others take place throughout development, peaking at adolescence and reaching their base around the age of 21, and transform the brain to create more complex and efficient neuronal configurations.