Anatomical and Chemical Changes Involving Learning Memory Storage
According to Kandel, Schwartz, Hudspeth & Jessell (2013), learning occurs when an individual is capable of using some basic experiences, training, and instructions to acquiring new skills. Knowledge is acquired and retained in the nervous system through a process known as memory storage. Moreover, the brain has the ability of restructuring throughout the process of learning new things, and this process is called brain plasticity.
Through various experiments, it has been noted that to acquire different memories through the learning process, there is the involvement of different neurons. This was evident in the study of Landon cab driver, who had a large anterior of his hippocampus than the other workers with good spatial memories. From these cab drivers memories, it was been noted that their brains were altered by working hard on memorizing the city. In fact, the new recruits in-cab driving had been noted to possess a lower posterior memory compared to their longest working mates.
As noted by Kandel el at (2013), memories can be either implicit or declarative depending on how they were acquired. Implicit memories are the ones acquired through learning processes like sensitizing the bodies, associating and priming to some objects, which makes the neural system store the memory part of skills or habits. However, declarative memory is a conscious constituent that stores facts or events.
Every new learning is usually followed by changes in the neurons interior structure, and the number of synapses between relaying neurons is usually increased (Carlson, 2012). Moreover, it has been noted that short-term memory, which is responsible for remembrance of some information, is usually associated with both chemical and electrical changes in the brain. Various brain tests have shown that training, familiarity and instructions cause quantitative changes that are recorded in the brain of animals (Carlson, 2012). In addition, it was also noted that, memories were recorded in different parts of the brain, and are usually disseminated through the neural network of the body.
Neural system processes several things at the same time in the body regardless of the organism’s age, thereby keeping records of memory in the hippocampus part of the brain (Kandel et al, 2013). A study conducted on birds revealed that a bird without hippocampus can search for food normally, but after storing the food for some time, it could not remember location of the food storage, or even the way to retrieve it.
Occurrence of short-term learning makes a change in the previously existing neural network. Local neuron changes the way they relate to other neuron systems, and this modification in neural chemical processes is used to determine cellular changes and varying activities used by various mechanisms of cells. However, the rate of firing postsynaptic neuron system is considered normal, and it depends on the level of excitement conveyed to presynaptic neurons (Kandel et al, 2013).
On the other hand, in order to establish a long-term memory, it requires synthesis of new proteins and the occurrence of growth to the pre-existing cellular frame. The long-term memories require a highly complex plastic change of the brain as compared to short-term changes. The entire postsynaptic system undergoes modification since the normality in postsynaptic firing is changed. Postsynaptic neurons have been observed to maintain firing even when the elevated stimulation is restrained (Hyman, Malenka & Nestler, 2006).
Drugs Mechanisms that Affect Memory
Some drugs have been noted to draw pleasure to human bodies and animals. In order to do this, the drug stimulates certain brain parts such as a vetra tegmental (Hyman, Malenka & Nestler, 2006). In related studies, scientists could stimulate this part of the brain during certain activities, and the animals would do more of these activities, so that they would continue getting those pleasures. By stimulation, they affected a brain neural path of pleasure receptors called the reward pathway.
However, unlike pleasant activities, during the pleasurable moment drugs affect a receptor called dopamine situated in the reward pathway. Extent to which the receptor is affected depends on the type of drug being used. Through dopamine receptors, some drugs have been noted to cause improved mood in the depressed patients. In fact, they get away to inhibit secretion of some hormones and control patient’s mood, or increase secretion of others leading to a spectacular improvement in the patient’s mood (Hyman, Malenka & Nestler, 2006).
Hyman, Malenka & Nestler (2006) claim that if drugs are taken for a long time, addiction develops and sometimes leads to brain damages. In fact, almost every addicting drug has a different way of causing its addiction, but they mostly do it through dopamine receptors. The cell levels may be reduced due to overstimulation of some new structural change in receptor cells; in fact, they even change their shape. Other drugs like cocaine inhibit fundamental biological processes like the reuptake of neurotransmitters at the end of the presynaptic membrane and the transporters of the neurotransmitters.
In conclusion, an organism’s survival as an individual and continuation of generation necessitates that they learn various ways in which they can obtain bodily requirements like food and addiction like drugs. However, the response an animal takes towards useful natural rewards is equal to that of drug addiction.
Carlson, N. (2012). Physiology of Behavior. (Ed.11). Upper Saddle River, NJ: Pearson
Hyman, S., Malenka, R. & Nestler, E. (2006). Neural Mechanisms of Addiction: The Role of Reward-Related Learning and Memory. Reviews in Advance. Web.
Kandel, E., Schwartz, J., Hudspeth A. J. & Jessell, T. (2013). Principles of neural science. (Ed. 5). Washington, D.C: Book News, Inc.