The Cytoarchitecture Of Schizophrenia
Since neurodegenerative abnormalities are uncommon in, and probably epiphenomenal to, schizophrenia, the question is raised as to what the pathology of the disorder is, and how the macroscopic findings are explained at the microscopic level. This brings us to the heart of recent schizophrenia neuropathology research, which has been the increasingly sophisticated measurement of the cortical cytoarchitecture. The focus has been mainly on the extended limbic system , encouraged by suggestions that psychotic symptoms originate in these regions .
Table 1 summarizes the morphometric investigations in which neuronal parameters such as density, number, size, shape, orientation, location and clustering have been determined. Table 2 summarizes the studies of synapses, dendrites and axons, evaluated either ultrastructurally or indirectly using immunological and molecular markers. Both tables are subdivided by brain region. Only the major findings are listed; details such as laterality effects are omitted. In the following sections the main themes of this literature are discussed, although even the choice of what to highlight is problematic given that controversy surrounds nearly every point.
Studies of neurons
Cytoarchitectural abnormalities in entorhinal cortex.
Disarray of hippocampal pyramidal neurons.
Location of cortical subplate neurons.
Hippocampal and cortical neuron density and number.
Hippocampal and cortical neuronal size.
Neuronal morphometric changes in other regions.
Sympathetic Nervous System Research Paper
Medications used for nervous system disorders such as: ADHD, Schizophrenia, Bipolar Disorder and more have been used for years to treat these disorders and others. Most medications have a positive effect on a person, when used correctly and with the right body chemistry. Other times, these medications can cause more harm than good.Some adolescents misuse medications. A few examples are methylphenidate and dexamphetamine . Both medications are sympathomimetic, which produce
How Early Do The Brain Changes Begin
There are two large and interesting independent, studies of people with a prodromal syndrome that, is high likely to lead to schizophrenia – one in Scotland- and another in Melbourne, Australia . Both these studies have performed very parallel investigations. Initially during the prodrome, a change in brain structure seems to be present in the temporal lobe volume and cingulated. On follow-up in those who have gone onto a psychotic episode, further changes can be seen in the cingulate, temporal lobe, and parahippocampal gyrus. These two independent studies have results that are not entirely consistent with each other, but it is interesting that neither show ventricular enlargement, or its progression at this stage. In general, while both research groups see initial changes in temporal and frontal lobes in people who later develop schizophrenia and progressive change in the time interval from prodrome to onset, of clinical illness, the specific changes that are clearly predictive of illness need to be further delineated.
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How Does Schizophrenia Affect The Mind
A person with schizophrenia cannot think normally. Although there are many kinds of schizophrenia and many symptoms of the disorder, all people with the disease have difficulty thinking rationally. They may experience disorganized thoughts or experience hallucinations or delusions. Often, what a person with schizophrenia says will not make sense, as it will appear disconnected or unintelligible. Schizophrenia also affects the ability of the mind to feel emotions, as people with the disorder do not feel or express emotions normally.
Development Across Disease Progression
Gross neural anatomy can be clearly visualized at a resolution of about 1 cubic millimeter with MRI, a technique that measures the effects of strong magnetic fields on different tissue types to create high-resolution images of internal structures. Because MRI techniques are noninvasive and do not involve ionizing radiation, brain images can be acquired repeatedly in awake performing subjects, making well-controlled, large-scale, and longitudinal studies possible. Using this technique, complex patterns of structural abnormalities have been found in schizophrenia patients as well as in those at risk for the disorder.
In MRI studies of schizophrenia, the most consistent findings include reduced gray matter volumes of the medial temporal, superior temporal, and prefrontal areas. These are regions on which episodic memory, processing of auditory information, and short-term memory/decision making, respectively, are critically dependent. Gray matter abnormalities in schizophrenia are partially hereditary, as shown in twin and candidate gene studies, and they are partially modulated by intrauterine risk exposures such as fetal hypoxia . Postmortem studies indicate that cortical gray matter reduction does not reflect loss of cell bodies but, rather, reduced dendritic complexity and synaptic density, which may impact interneuronal communication and integration .
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Neuroleptics And Progressive Brain Change
Lieberman and colleagues recently published a paper in the Archives in General. Psychiatry from a study comparing olanzapine with haloperidol in first-episode patients and comparing any brain changes to control changes over time. They claim that, over a 2-year period, whole gray matter volume decreases significantly more in patients administered haloperidol than in controls or patients on olanzapine. However, the time of the follow-up MRI scans was short; there were many dropout subjects in this study and disproportionately among the groups; and some time periods were missing in one group entirely, thus hampering interpretation of these results.
There have now been several other studies attempting to examine the question of neuroleptic effects on brain structure. While it, appears consistently in most, but, not all, studies that the caudate enlarges with typical neuroleptics, the changes seen with respect, to other cortical regions and ventricular enlargement have yet to be shown to be due to medication .
Antipsychotic Drugs May Work By Changing Brain Structure Other Changes May Be Due To Side
Changes in brain structure are caused both by the disease process of schizophrenia and bipolar disorder and by the antipsychotic drugs used to treat these diseases. Different antipsychotic drugs may have different effects. It is important to study the brain changes caused by antipsychotic drugs, since this may tell us how these drugs work and/or predict which individuals are more likely to experience side effects. The changes caused by antipsychotic drugs used to treat schizophrenia and bipolar disorder are similar in kind to structural brain changes caused by drugs used to treat Parkinsons disease, epilepsy, and other brain diseases. It is incorrect to characterize these brain changes as an indication that these drugs are dangerous or should not be used.
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Schizophrenia Changes Brain Structure: A Review Of Studies Of Individuals With Schizophrenia Never Treated With Antipsychotic Medications
A review of 56 studies of individuals with schizophrenia who had never been treated with antipsychotic medications indicates significant abnormalities in brain structure and function. Neurological and neuropsychological measures show the most consistent and largest group differences between those affected and normal controls. Measures of structural differences and cerebral metabolic function are significant but less impressive. Electrophysiological differences also are found, but most such studies are older and have methodological problems. The brain abnormalities implicate a variety of interrelated brain regions, primarily the medial temporal, prefrontal, thalamic, and basal ganglia areas. It is concluded that schizophrenia is a brain disease in the same sense that Parkinsons disease and multiple sclerosis are, and that the brain abnormalities in schizophrenia are inherent in the disease process and not medication-related. The challenge for the future is to use the new molecular techniques to study these brain areas and elevate our understanding of schizophrenias etiology to the next level.
Magnetic Resonance Spectroscopy Studies
There is substantial evidence that neurometabolite levels are altered in both schizophrenia and BD. A meta-analysis pooling data from 146 studies suggests decreases in NAA in the frontal lobe, hippocampus, thalamus, and basal ganglia in schizophrenia, but only in the basal ganglia and frontal lobe in BD. Another meta-analysis summarizing findings of glutamatergic abnormalities across 28 studies in schizophrenia revealed a decrease in medial frontal glutamate compared with healthy controls, but the majority of studies were conducted in medicated patients. Contrastingly, several reports do suggest an elevation of glutamatergic indices in unmedicated patients with schizophrenia in the medial prefrontal cortex, striatum, and hippocampus.,,, A smaller meta-analysis in BD including nine studies measuring Glx across different areas of the brain, suggested that this metabolite may be higher in patients with BD compared to controls, irrespective of medication status. Taken together, it appears that some of the neurometabolite alterations, specifically decreased NAA in the frontal cortex and basal ganglia may be shared across the illness spectrum, whereas others may not.
Table 5 Studies examining magnetic resonance spectroscopy
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Clinical Features Of Schizophrenia
Schizophrenia remains a clinical diagnosis, based upon the presence of certain types of delusions, hallucinations and thought disorder . These `positive’ symptoms are often complemented by the `negative’ symptoms of avolition, alogia and affective flattening. The criteria of the Diagnostic and Statistical Manual of Mental Disorders , used for most research studies, require symptoms to have been present for at least 6 months; there must also be impaired personal functioning, and the symptoms must not be secondary to another disorder . The peak age of onset is in the third decade, occurring a few years earlier in males than in females . The course and outcome are remarkably variable, but better than sometimes believed; only a minority of patients have a chronic, deteriorating course, though many others have enduring symptoms or functional deficits . There is a significant excess of mortality from suicide and natural causes . The lifetime risk of schizophrenia is just under 1% . It has a predominantly genetic aetiology, but no chromosomal loci or genes have been unequivocally demonstrated .
Not The Smoking Gunbut A Piece Of It
The team admits that studying hallucinations in mouse models is not ideal, since, of course, the animals cannot communicate their experience. However, the researchers note that the same types of drugs that cause hallucinations in humans also cause visible movement and behavioral changes in mice.
This, the investigators explain, reasonably suggests that the same drugs alter brain activity in both animals and people. However, future studies should pay closer attention to the animals reactions to visual stimuli in the presence versus the absence of drugs.
I dont feel like weve necessarily found the smoking gun for the entire underlying cause of hallucinations, but this is likely to be a piece of it, Niell says.
The data weve collected will provide a foundation for additional studies going forward. In particular, we plan to use genetic manipulation to study particular parts of this circuit in more detail, the senior researcher adds.
And since previous research has suggested that serotonin 2A receptors which the researchers also targeted in this study are involved in schizophrenia, Niell and team would also like to find out whether their present findings may provide new perspectives regarding the treatment of this and other mental health conditions.
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Early Symptoms Of Schizophrenia
Because early treatment is thought to be most effective for schizophrenia, researchers are continually looking for ways to detect it before symptoms fully develop.
Although psychotic symptoms such as hallucinations or delusions are the most common aspects that present in schizophrenia, there are several symptoms involved. People with schizophrenia experience:
- Positive symptoms: The appearance of things that should not be there, like hallucinations, delusions, and thought disorder .
- Negative symptoms: The absence of things that should be there, like loss of motivation, disinterest or lack of enjoyment in daily activities, social withdrawal, difficulty showing emotions, and difficulty functioning normally.
- Cognitive symptoms: Problems with attention, concentration, and memory.
Assessment of these symptoms is typically how schizophrenia is diagnosed, but the discovery of brain differences in people with schizophrenia could potentially mean an earlier diagnosis and more effective treatment.
While schizophrenia is usually diagnosed in the late teens to early thirties, subtle changes in cognition and social relationships may be noticeable before the actual diagnosis, even during adolescence. Often these early symptoms are apparent years before a person is diagnosed with schizophrenia.
Some of these early symptoms include:
How Does Schizophrenia Affect The Body
Schizophrenia is primarily a disease of the mind. Most of its effects are mental or emotional in nature. However, the disease can affect the body in some key ways. Brain modifications cause the disorder to occur, although what causes the brain modifications is unknown. In addition, schizophrenia may cause sufferers to do harm to their physical bodies, as alcohol abuse, violence, and self-destructive behavior are all complications of the disorder.
Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.
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What Happens After You Get The Results From A Schizophrenia Brain Scan
If brain scans are ordered for a person who is showing schizophrenia symptoms, it is usually to rule out or confirm other conditions that could be causing the symptoms.
Whether the scan shows a different condition or plays a part in confirming a diagnosis of schizophrenia, the healthcare provider will discuss treatment options.
Review Coverage And Methodology
The review focuses on the key points of agreement and of controversy affecting the robustness of the data and their interpretation. It comprises a comprehensive survey of contemporary neurohistopathological research, with restricted coverage of earlier work and of related fields such as neuroimaging and neurochemistry.
The sources for the review consisted of: papers identified using a range of keywords for on-line searches of Medline, PsycLIT and Biological Abstracts , weekly scanning of Reference Update from 1989 to October 1998 using a similar range of keywords, and an extensive reprint collection and perusal of each article’s reference list. Only data published in full papers in peer-reviewed English-language journals were considered for inclusion.
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Discuss The Biological Approach In Psychology Essay Example
physiological explanations, such as the effect of nerves and hormones on behaviour. According to biological psychologists, behaviour is controlled by the nervous system, which consists of the central nervous system and the peripheral nervous system , which itself includes the autonomic nervous system that controls automatic processes such as heart rate and the fight or flight syndrome. Within the central nervous system,
‘little Brain’ Plays A Major Role In Schizophrenia
- University of Oslo, Faculty of Medicine
- The cerebellum is among the most affected brain regions in schizophrenia, new research has found. Compared to healthy individuals, cerebellar volume was smaller in patients with schizophrenia. The study is the largest brain imaging study to date on the cerebellum in schizophrenia, with important implications for our understanding of the disorder.
In a new study, Norwegian researchers have documented that the cerebellum is among the most affected brain regions in schizophrenia. Compared to healthy individuals, cerebellar volume was smaller in patients with schizophrenia. The study, published in Molecular Psychiatry, is the largest brain imaging study to date on the cerebellum in schizophrenia, with important implications for our understanding of the disorder.
Although the cerebellum occupies only about 20% of the human brain, it actually contains about 70% of all its neurons. This brain structure has traditionally been thought of as responsible for body movement and coordination, and has therefore often been ignored in research on the biological basis of psychological functions and mental disorders.
The current study included brain scans from 2300 participants from 14 international sites. The researchers used sophisticated tools that allowed them to analyze both the volume and shape of the brain.
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When A Loved One Has It
Relationships can be rocky for people with schizophrenia. Their unusual thoughts and behaviors may keep friends, co-workers, and family members away. Treatment can help. One form of therapy focuses on forming and nurturing relationships. If you are close to someone who has schizophrenia, you may want to join a support group or get counseling yourself, so you can get support and learn more about what they are going through.
Changes In Behaviour And Thoughts
A person’s behaviour may become more disorganised and unpredictable.
Some people describe their thoughts as being controlled by someone else, that their thoughts are not their own, or that thoughts have been planted in their mind by someone else.
Another feeling is that thoughts are disappearing, as though someone is removing them from their mind.
Some people feel their body is being taken over and someone else is directing their movements and actions.
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Summary: Neurophysiology Aspect Of Schizophrenia
MoralesNeurophysiology Aspect of SchizophreniaBiological PsychologyPSY 6645Dr. DawsonSchizophrenia is described by dissolution of thinking processes and emotional responsiveness. It is most frequently manifested through delusions, auditory hallucinations, disorganized thinking and speech, and paranoid delusions and may affect social or occupational functioning depending on symptoms and severity. The immense majority of individuals with schizophrenia are not violent and do not pose
Strucutural Changes Caused By Antipsychotic Medications
There is considerable ongoing work in this research area. The majority of the work to date has been carried out in rats and needs to be replicated in humans, since there are substantial species variation in brain structure and function. The following structural brain changes appear to be caused by antipsychotic drugs.
These changes appear to be caused both by the disease process and by the effects of antipsychotics, so it is difficult to determine how much is caused by one and how much by the other. In addition, the studies of antipsychotic drug effect have been inconsistent, with the majority of studies showing an effect, but a minority not showing one.
Moncrieff J, Leo J. A systematic review of the effects of antipsychotic drugs on brain volume. Psychological Medicine 2010;40:14091422.Navari S, Dazzan P. Do antipsychotic drugs affect brain structure? A systematic and critical review of MRI findings. Psychological Medicine 2009;39:17631777.Boonstra G, van Haren NEM, Schnack HG et al. Brain volume changes after withdrawal of atypical antipsychotics in patients with first-episode schizophrenia. Journal of Clinical Psychopharmacology 2011;31:146153.
Increase in size of the striatum.
Chakos MH, Lieberman JA, Bilder RM et al. Increase in caudate nuclei volumes of first-episode schizophrenic patients taking antipsychotic drugs. American Journal of Psychiatry 1994;151:14301436.
Increased density of glial cells in the prefrontal cortex.
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