Physiology Of Memory And Aging Essay

Once you reach a certain point in your life how do you just forgot? Is there a certain point in your life where your memory is affected? The common question going around is does your memory decline with age. One reason this is important because it will affect all of us. We will all get old and this can greatly affect our health. The research can show how our older age will affect our memory.

As we age, our brain and nervous system go through natural changes. An aging adult may experience memory loss, decreased touch sensation, change in the perception of pain, change in sleep pattern, decreased coordination and increased risk for infection (Ignatavicius, 2013, p. 912) .

McLeod (2007) describes memory as the psychological function of processing & preserving vast amounts of information such as visual images, acoustic sounds and semantic meanings. According to the Oxford Dictionary of Psychology (2009), memory involves a series of interconnected systems that serve different functions. The basic divisions of these systems are declarative and procedural memory, episodic and semantic memory and long and short term memory.

Some scientists believe that parts of long term memory are permanent while others will eventually weaken over time. (3) Long term memory can be divided into three sections: procedural memory, declarative memory, and remote memory. Procedural memory includes motor skills such as learning how to ride a bike or how to drive a car. "Such memories are slow to acquire but more resistant to change or loss." (4) Declarative memory is used to remember facts, such as names, dates and places. It is easy to learn but also easy to lose. Finally there is episodic memory, which is the record of events that a person stores throughout his or her experience. Recent studies show that these events, as soon as they occur, are sent to a temporary part of the brain called the hippocampus, and that over time they are moved to the neocortex for permanent storage. (5).

Cognitive aging is commonly labeled strictly as memory and only found in “some people”. However, this is not true. The knowledge of cognitive aging has grown immensely, but there is still much to be learned. The surface has only been scratched with many more questions to be answered. Cognitive aging is worthy of study and effects everyone, but there is also much more is still to be learned.

For example, it is well known that the left hemisphere is responsible for the encoding and recall of verbal memories, whereas the right cerebrum is dominant in regard to visual-spatial, non-verbal, and emotional memory functioning (Joseph 1982, 1988a, 1990a,b, 1992, 1993, 1996, 2003). If the left temporal lobe were destroyed, verbal memory functioning would become impaired since the right cerebrum does not readily store this type of

There are various advantages and disadvantages of different study designs when investigating cognitive and neural ageing using neuroimaging. Several theories of cognitive ageing have been based on cross-sectional designs where there is a common understanding that multifarious age studies can lead to a better understanding of the propinquity among age-related processes (Hofer, Sliwinski and Flaherty, 2002). This method is proven to be cost effective, renders quick results, and is the best way to determine prevalence and identifying associations within a group (Mann, 2003). However, Salthouse (2009) pointed out that comparisons of people of different ages at a particular time does not necessarily express changes that will arise within an individual as he ages. He explained that confounding factors, such as maturation, which refers to the person growing older and undergoing different experiences and influences, must be determined in each participant to know how each one has been effected. Raz and Kennedy (2009) also identified in a review that cross-sectional studies have often only focused on specific parts of the brain in imaging studies, such as the prefrontal cortex, but many longitudinal studies present larger age-related structural changes in the inferior parietal cortex, the hippocampus, and the cerebellum.

Why does the human brain age? Brain aging is a part of human life and a big part of society as the awareness for brain aging increases. Over time memory tends to become less efficient as we age and the neurons in the brain decreases (Bendheim, P.E. (2009). By 2050 in the US, 20 percent of the population will be 65 years or older. And as the elderly population increases, so will the incidence of age-related neurological disorders (Perlmutter, David. (2004). Therefor it is important to understand the aging brain, and how to keep the brain functioning as one ages.

This type of Amnesia a person has brain trauma that has affected the hippocampus, the fornix which is located inside and continuing on the outside of both sides of the hippocampus or the mammillary bodies which are connected by a nerve path to the fornix. It can also temporarily be drug-induced, by alcohol intoxication, brain surgery, heart attack, concussion, shock and even an emotional disorder. This type of Amnesia affects the patient by not being able to store memories caused after the Amnesia for more than a few minutes. For example the patient is unable to remember the name of a person that he or she encountered 5 minutes ago. (healthline), (medindia), (wisegeek), (Human)

The cerebrum is separated into four lobes by the deep fissures in the cerebral cortex. The frontal lobe, temporal lobe, occipital lobe, and parietal lobe all have different functions that work together to keep the human body running. The frontal lobe is located in just behind the forehead and makes up about half the volume of the human cerebrum. It receives and coordinates messages from the other three lobes and keeps track of previous and future movements of the body. The frontal lobe also has a pivotal role in behaviors that are associated with personality. Furthermore, the primary motor cortex, which covers the area on the surface of the frontal lobe, plays a key role in the voluntary action.

Neurogenesis is defined as the creation of new brain cells. Before studies proved that neural cells do have the capacity to proliferate and repair themselves, it was often believed that species are born with a distinct amount of neural cells and as time passes, these cells would die without the ability to be healed or replaced. It was thought that the cells were mainly formed during the embryonic and perinatal stages in the mammals (Ming and Song, 2005). The first piece of evidence that proved that neural cells can be formed throughout the life of a mammal was found by Altman. He found that there were newly formed granule cells in a postnatal rat hippocampus (Altman and Das, 1965). In humans, there are two main regions that were found to have an active amount of neurogenesis. One is the subgranular zone (SGZ) which is located in the dentate gyrus of the hippocampus. It is here that new dentate granule cells are generated. The other is the subventricular zone (SVZ) of the lateral ventricles. Neurons are generated in this area and are migrated through the rostral migratory system (RMS) to the olfactory bulbs where they become interneurons (Gage, 2000). A question scientists continuously investigate is whether or not there is a decrease in an organism’s ability to regenerate and repair neural cells as they age, and if this there is a limit on their ability to regenerate these cells, are there genes or proteins that

Dennis, Kim, and Cabez (2008) investigated the effects of getting older on neural activity. The study consisted of sixteen younger adults and seventeen older adults. The participants had no sort of mental disorders. For this experiment the participants were shown word-lists that were put into categories and were used for the retrieval of true and false memories. Dennis et al.,(2008) found that older adults do have a poorer performance rate than younger adults. The older adults were very confident in their false answer. But in regards to the true retrieval activity there was an age related

As we progress through life, it seems that simple things become difficult to recall. The question is does memory decline with age. There have been numerous debates about whether age has any correlation with memory deterioration or if our lapse in the recollection of our memories is contributed to stress we are experiencing. Another important factor that we must consider is the illnesses that are linked to memory loss such as Dementia and Alzheimer’s disease. How does a researcher examine memory decline in humans in respect to age? Biology plays a key role in aspect to memory loss and the illnesses associated with memory loss; gender also seems to be a significant factor when discussing memory deficits.

(A) SIGNIFICANCE: Despite the advances in our understanding of aging [1,2,3,4], the physiological and molecular correlates of aging-dependent alterations in specific neurons that underlie learning and memory storage are poorly understood. Such information is essential to delineate molecular underpinnings of aging-related changes to develop novel strategies for therapeutic intervention of the aging-associated specific deficits in learning and memory storage. Our proposed studies are highly significant to the studies on human aging and cognition in three major ways. (1) This proposal is highly relevant to human learning because of the focus on mechanisms of aging dependent changes in learning using a simple, but well characterized neural circuitry - the gill withdrawal reflex (GWR) of Aplysia. It is important to recognize that many concepts that are central to our overall understanding of learning and memory were established using Aplysia. For instance, the role of the cAMP signaling system, or branch-specific storage of memories discovered in Aplysia has also been shown to be important in Drosophila and the mouse [5]. Therefore, it is expected that contributions of the proposed studies on aging will be conserved in mammals. (2) Because of two main reasons studying aging using defined synapses is critical for identifying specific cellular and molecular mechanisms of aging associated memory decline. First, studies using populations of neurons will dilute the specific changes

Memory formation takes place in the nervous system and these memories are mediated by gene expression where long-lasting changes take place between neurons in synaptic connections. In 1949, Hebb postulated, when two neurons are activated at the same time, strengthening of synaptic efficiency will result in the appropriate synapse (Lynch, 2004). Since then efforts have been channeled into understanding mechanisms responsible for synaptic strengthening refereed to as long-term potentiation (LTP), which has also been investigated for its link to memory formations and has become an emerging model for memory encoding. Several areas of the brain play a role in consolidation of learning and memory, however LTP is most easily demonstrated in the hippocampus, an area of the brain believed to serve as a holding store for memories (Abraham et al., 2002). Scoville and Milner (1957) reported, treating a patient (H.M) suffering from epilepsy and psychosis with bilateral hippocampal removal, resulted in anterograde amnesia and a grave loss of recent memory (Lynch, 2004). Further studies showed repeated stimulation of hippocampal neurons induce prolonged increase of LTP (Frey and Morris, 1996), highlighting the importance of memory and the hippocampus. The three well-described characteristics of LTP are durability, associativity and co-operativity and input specificity (Lynch, 2004).These support LTP as a biological substrate for multiple forms of memory. The wider clinical implications