A paper which studies the effects of the Superfund Neurotoxin Methylazoxymethanol (MAM) on brain dendritic spine density in long hooded Evans Rats Rattus norvegicus.
Abstract The paper shows that in the study of structural development in the brain there have been several proposed biomarkers for quantifying brain plasticity. These include but are not limited to cortical thickness, dendritic length and branching, expression of neuronal proteins, and the presence of DNA adducts. The paper discusses the theory that a measure of brain plasticity emerging late in embryonic development will be a very sensitive biomarker for detecting subtle damage suffered by brain cells during earlier stages of brain development not detectable by other means. The paper shows that to test this, the effects of a neurotoxin on the late developing dendritic spines were studied. A significant decrease in spine density was observed as the neurotoxin, methylazoxymethanol, increased. The author of the paper shows how the implications are widespread in the study of neuro-degenerative disease.
From the Paper "Fifty years ago, Donald Hebb demonstrated that the conditions under which laboratory rats were housed could significantly affect their performance in a variety of complex spatial tasks later in life (1). The complex environment rearing paradigm has been valuable in assessing plasticity of a variety of brain components including cerebral cortical microvasculature, astrocyetic morphology, dentritic branching patterns, synaptic number, and synaptic structure are all affected by complex environment rearing (2). It has been suggested that multiple synaptic contacts (spines) may play a role in the spread of the additive effect of learning known as potentiation, among neighboring unstimulated neurons. A lack of these spines and their connection with boutons of neighboring neurons could then result in a decrease in the capacity for learning. Some recent work has indicated that the presence of multiple synaptic contacts may be altered by experience. Most of this research has focused on structural changes in the hippocampus. Dendrtic spines show great variability in structure and connectivity, both within and across brain structures, including 10-fold differences in length and diameter as well as variations in the number of branches and spines per dendrite."
This paper highlights the advances in imaging technology that have allowed scientists to discover how memory works and the areas of the brain involved.
Abstract This paper looks at how the different advances in brain imaging-techniques have contributed to scientists increased ability to understand the concept of memory. It looks at the advent of Computed Tomography (CT), Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET), and what they have meant to the increased ability to understand and treat brain, and memory disorders.
From the Paper "For example, fMRI was found useful for research by Awh and colleagues (1999) to observe brain activations during the performance of a spatial working memory task. In this investigation, subjects were given a spatial working memory task and a control task. Using fMRI the researchers found a functionally distinct, region that showed sustained activity during the spatial working memory task, confirming the location for the neural bases for that function. In the past, researchers who wanted detailed studies of human brain activity struggled because they lacked effective investigative tools. In experiments with humans the best technologies brought only limited success in mapping the processes of consciousness."
Abstract This paper discusses the importance of using brain-based education research for teaching adult learners. It examines findings from brain-based research, information regarding the adult learner, and the use of brain-based education for adult learners.
From the Paper "This research paper presents the importance of using brain-based education research for the teaching of the adult learner. Findings from brain-based research information regarding the adult learner and the ..."
Tags:brain-based research adult learners, education
Abstract In this article the writer discusses the function of the brain within people with autism. The writer firstly defines the neurological disorder of autism that affects each individual in a different way. It should be noted, however, that autism negatively affects normal brain function. The writer notes that many individuals with autism have been considered remarkably intelligent, despite their difficulties relating to the rest of the social order. Further, the writer points out that due to these variances in the manner that autism is present in the affected individual, the issue of brain development comes into question.
From the Paper "Children with autism may not begin to show signs of the developmental disorder until they have passed infancy. A neurological disorder, autism cannot be defined by standard criteria that are universal to all patients because the disorder affects each individual differently. It should be noted, however, that autism negatively affects normal brain function. As the disorder progresses it will inhibit the individual's ability with social interaction and communication."
Abstract This paper looks at the process of metabolism and how it is changed during starvation to keep the brain supplied, first with glucose, and when that is exhausted, with acetyl-CoA. It then looks at the effects of starvation on the brain and how these problems can be corrected.
Abstract This paper looks at the development of the brain from the moment of conception to one year of age. It looks at the development of gender, gender differences in the brain, cognition, and how cognitive function changes through adulthood into old age.
From the Paper There is a four-year period of potential growth lasting from conception until around the third birthday, which is the most critical period for human development. Maria Montessori called this La mente del bambino or the time of the absorbent mind. The brain is composed basically of two types of cells; the neurons which are the nerve cells and the glial cells which are the supportive cells. Information is integrated in the cell bodies of the neurons and travels as an electrochemical impulse along the axon where the..."
Abstract This paper discusses how the brain learns from a physiological standpoint and what the current state of research is. It explores issues cited such as the knowledge of brain physiology and the developmental changes that enable learning. The author of the paper claims that cited literature gives a perspective that learning is intangible and is only evidenced by changes in physiology. The paper considers how the physiological changes happen and how they relate to intangibles related to learning.
Abstract The paper relates that there are many studies into the long-term effects of heavy alcohol use and notes that it may lead to shrinkage of brain material. This in turn may lead to short-term memory deficits. The paper also relates that it is known that heavy alcohol use impairs the hippocampus which affects memory.
Outline:
Introduction
Brain Shrinkage and Short Term Memory Loss
Hippocampus Activity and Memory Loss
Conclusion
From the Paper "As discussed earlier in the essay, heavy consumption has been associated for some time that with reductions in the numbers of cholinergic neurons in the forebrain. The forebrain cholinergic neurons are distinguished into two groups, those of the basal ganglia and those of the basal forebrain. The cholinergic neurons of the basal forebrain project to the cortical regions, and the most rostral of these project to the allocortical regions such as the hippocampus. Therefore reductions in numbers of these cholinergic neurons will lead to reductions in activity of these allocortical regions, including the hippocampus. It is also possible that alterations in modulatory transmitter inputs such as cholinergic innervations may also play a role in the reduction of hippocampus activity without the actual loss of cholinergic neurons themselves. However in tests which have been performed on rhesus monkey models it has been shown that hippocampal activity reduction which is related solely to these alterations in modulatory input and not reductions in numbers of cholinergic neurons are unrelated to observed changes in memory function of any kind (Calhoun 475). This does not mean however that the reduction in hippocampal activity related to actual loss of cholinergic neurons does not lead to degeneration of memory function."
Abstract This paper discusses the history of signature wounds from various wars. According to this paper, the Iraq War has resulted in a large number of traumatic brain injuries. This paper goes on to discuss the causes and nature of this injury.
From the Paper "In every war, historians recognize that there will probably be at least one signature wound that will characterize that war for posterity. Incidences of radiation sickness from the atomic bomb will forever distinguish World War II. The Vietnam War still lives on in highlighting the effects of post-traumatic stress disorder. The current Iraq War will be no different. In fact, military doctors are already aware of the signature wound of this conflict, one that is slowly dawning in the public eye. For a variety of reasons--including protective armor and enemy tactics--traumatic brain injuries (TBIs) are emerging as one of the most devastating and widespread injuries among U.S. casualties of the Iraq War. Traumatic brain injury has a number of causes. However, the nature of the wound and its effects are well documented."
Abstract The paper shows that extracranial brain tissue that is not directly connected to the brain itself may be an isolated cutaneious embryonic defect. It discusses how these are usually located on the occipital or parietal areas of the scalp and are often called heteropic brain tissue or cutaneous ectopic brain (CEB). Most of the time these are simple defective tissue that can easily be removed from the scalp. However, there are several different types of ectopic brain tissues and some of these can be signs of underlying central nervous system problems. The paper discusses several cases where the importance of getting a thorough evaluation of the tissue is shown.
Table of Contents:
Definition of Cutaneous Ectopic or Heterotopic Brain Tissue
Summary of Four Patients with Scalp Nodules Surrounded by Hair Collars In the Study by Drolet and Clowry
History of CEB
The Hair Collar Sign: Marker for Cranial Dysraphism
Why the "Hair Collar"
Ectopic Brain as Orbital and Conjunctival Mass
Heterotopic Brain and Meningeal Tissue
Information about Heterotopic and Ectopic Brain Tissue
From the Paper "Perhaps the question can be asked why the researchers termed the phrase, "hair collar". Why is there a hypertropic ring of long hair that surrounds these lesions? If these were examined, the hair follicles would be found to increase in number and many of these will be quite large. In fact, the angle that each hair follicle exits the skin does not fall randomly, but are located at precise directions that the hair follicles take.
? The hair pattern is thought to be dictated by differential shearing forces and the point of maximal tension, the vertex, is where the parietal scalp whorl is commonly found. Perhaps at some point early in development, encephaloceles and meningoceles produce aberrant shearing forces during the formation of the follicles forcing them to point outward, away from the defect? (Drolet and Lawrence 309).
Abstract This paper examines the functions of the three areas of the brain - the fore brain (Prosencephalon), the mid brain or the mesencephalon and the hind brain or the rhombencephalon; and explains how each region within the brain is adapted for a special task. The paper then analyzes the connection with the brain and language development and discusses some conditions such as "Broca Aphasia", with which people have the ability to understand language but find it difficult to express themselves.
Introduction
Brain and Language
The Broca's and Wernicke's Areas
The Critical Period
The Split Brain Condition
Conclusion
Bibliography
From the Paper "Our principal way of communication with the world is through language. Language is the medium through which we express our feelings to the outer world. The neural basis of our language and communicating ability is an interesting aspect of study and researchers have unearthed vital information pertaining to the language processing ability of the brain. The whole process of thinking and speaking is a bit complex though it seems rather simple to us. In short we are actually executing all the minor details like jaw movement, construction of the semantics, and the sound generation everything in split second that we fail to recognize the complex task that the brain handles so effectively. Researchers have found out that we produce about one sound every tenth of a second and yet with only an error margin of one sound error per million sounds. [David Caplan] This astounding performance speaks of the power and the capacity of the human brain."
Abstract In this article, the writer notes that while the mind remains the most important aspect of being human, the brain is physical and has physical characteristics that can be measured. This paper presents an overview of the human brain and cognitive measures that assess the state of the mind during the life of an individual, from prenatal formation through the end of life in either a normal manner or down the more unfortunate path of dementia. Specific attention is focused on adolescence and particularly the onset of puberty as well as effects on the adult brain from damage occurring during adolescence; a discussion of the occurrence of neurogenesis in the adult brain; the brain aging processes; newly emerging ideas of how the brain does its work and how these ideas may affect research and treatment of dementia related brain degradation.
Outline:
Conclusions
References
From the Paper "Raz also found no relationship between education and the onset of these various physical changes. It is interesting to consider the actions of neurogenesis in relation to both depression and aging, in light of the Schmitt and Raz studies. The long held belief of non-neurogenesis in adulthood may not only be wrong, but cessation of neurogenesis may actually be a trigger to move toward the final stage of life.
"While physical changes can be measured, providing opportunities for relatively rigorous statistical analyses, measuring changes in behavior as humans and human brains age, is a much more difficult task. A primary question - What is normal behavior? - must be assessed before any measurements can be made."
Abstract In this article, the writer notes that the brain is divided into two hemispheres - the left and the right brain - separated by a fold that runs from the front to the back. The two hemispheres are connected to one another by the corpus collosum, a thick cable of nerves, at the back of the brain. The writer discusses that the differences in the two sides lead to different learning styles, dependent on an individual's dominant side of the brain. The writer maintains that while the two styles discussed are appropriate for either dominant side, each side additionally had three unique learning styles that seek to capitalize on the way left-brained or right-brained individuals are more likely to learn.
Outline:
Abstract
Hemispheric Dominance Overview
Learning Differences Between Left and Right-Brained Individuals
Conclusion
From the Paper "Those with left hemisphere dominance tend to excel in handwriting, symbols, language, reading, phonics, locating details and fact, talking and reciting, following directions, listening, and auditory association. Left-hemisphere brands have linear, symbolic, sequential, logical, reality-based, and temporal modes of consciousness. Those with right hemisphere dominance, on the other hand, tend to excel in haptic awareness, spatial relationships, shapes and patterns, mathematical computations, color sensitivity, singing and music, art expression, creativity, visualization, and feelings and emotions. Their modes of consciousness are: holistic, concrete, random, intuitive, fantasy-oriented, and non-temporal."
Abstract The philosopher Thomas Nagel became famous for his advocacy of the idea that human consciousness and subjective experience cannot be reduced to a discussion of "mere" brain activity and that the human brain is bifurcated into two hemispheres. The paper shows that in his essay on ?Brain Bisection & the Unity of Consciousness,? Nagel stresses that merely because this is the case, the sum or interaction of human being's two brain hemispheres of left and right is essentially greater than the catalogued capabilities of the two parts. Nagel stresses this as proof of his thesis that the human consciousness is more extensive than simply a list of the respective components of the brain's left and right hemispheres. The paper critically analyzes Nagel's view. It also touches on the growing research on gender differences between the interaction of brain hemispheres
From the Paper "Even if human beings are indeed all ?brain,? this does not mean that human beings will not vary in the ways that the different components of their brain interact in an interesting, varied, and compassionate manner. Nagel fears the potential predictability of the human consciousness as reducing the mysteries of human subjectivity to a catalogue of components. But to suggest, for instance, that the right brain might deal more with abstraction, as to the hemispherical components of left brain which are said to deal more with verbal capacity, can hardly predict the relative ability of any individual to use those abstractive or verbal capacities."
Abstract The paper overviews the functions of the human brain and its many parts. The paper first describes what our brain looks like and compares it to the brains of animals and fish. The paper then explores whether the mathematical and scientific abilities of geniuses have something to do with their brain development. Furthermore, the paper discusses the main function of the human brain that is its ability to store, retain and subsequently retrieve information. The brain activity that causes dreams is also discussed.
From the Paper "The human brain is a unique creation - it is wonderfully made to enable us to think, plan, move, see, speak, hear, taste, smell and imagine. It is the central organ of sensation, thought and the true seat of intelligence. The brain is responsible for the major functions of the body in order to survive. It is the one in charge of controlling the body temperature, blood pressure, heart rate and breathing. The human brain accepts and processes information through our senses - seeing, smelling, hearing, touching, and tasting. Even our capacity to handle physical motion when we do our daily activities is controlled by our brain. It dictates the parameter the way we talk, walk, sit, run, and perform other locomotors. It also has coordinating and regulating functions that allow us to use our logic, provide reasoning, experience emotions, and even to dream."
