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Autism

Description
Autism is a condition in which children are unable to develop normal relationships with others. It is a complex developmental disorder that appears in the first three years of life, though it is sometimes diagnosed much later. It is diagnosed by the presence of characteristic disturbances in development. It affects the brain's normal development of social and communication skills. Autism is a physical condition linked to abnormal biology and neurochemistry in the brain. The exact causes of these abnormalities remain unknown, but this is a very active area of research. Autism is a lifelong disease that ranges in severity from mild cases in which the autistic person can live independently, to severe forms in which the patient requires social support and medical supervision throughout his or her life. There are physical bases for autism's development including genetic, infectious, and traumatic factors. Viral infection during the first trimester of pregnancy, rubella being one of the best studied culprits, is a suspected cause of autism.

Who is at Risk?
About 4 of every 10,000 children are autistic, and 2 per 10,000 have some form of pervasive developmental disorder (PDD). PDD means that some, but not all, symptoms of autism are present. Autism affects males four times more often than females, and there is a genetic basis for the disease. Contrary to previous notions, autism is not induced by parents. Language and cognitive abnormalities are more common in relatives of autistic children. Family income, education, and lifestyle do not seem to affect the risk of autism.

Sources: The HealthScout Network, A.D.A.M., Inc.

A Protein That Affects The Shape Of Neurons
A century ago, much of the cutting-edge research in mental health was directed at understanding the psychological basis of psychiatric diseases: how memories and experiences play a role in our mental states. From this research emerged behavioral therapy, Freudian analysis, group therapy, and many other techniques that have been successfully applied to treatment in the field of mental health. Today, as we understand more and more about how the human body and the brain work on the cellular and molecular level, there is more interest than ever in the physiological basis for psychiatric diseases - the systems of interacting molecules and the chemical mechanisms through which these diseases manifest themselves. The reason for this interest is simple: there is an overwhelming need. According to the National Institute of Mental Health, over one fifth of all Americans -- more than 44 million individuals -- suffer from a diagnosable mental disorder in any given year. Now two scientists at The Scripps Research Institute are reporting a breakthrough in our understanding of the brain physiology that forms the basis for certain psychiatric diseases. In a recent issue of the journal Neuron, Associate Professor Shelley Halpain, Ph.D., and Research Associate Barbara Calabrese, Ph.D., describe how a protein called MARCKS affects the shape of neurons, particularly the part of the neurons known as dendritic spines, which are essential for learning and memory.

Because dendritic spines are so central to mental functioning, it's no surprise they are associated with neurological and psychiatric diseases. In mental retardation and autism, for instance, the shape of the dendritic spines are different. Under a microscope, the dendritic spines of many mentally retarded people are longer and appear more immature. In recent years, scientists have become increasingly aware of the possibility that a number of psychiatric and neurodegenerative diseases like Alzheimer's are also affected by synaptic changes brought about by spine morphology. The brains of schizophrenic patients or people suffering from mood disorders also show a reduced number of dendritic spines in the brain areas associated with these diseases. In the paper, the researchers show that MARCKS is a key player in the brain that affects the shape of these critical parts of human neurons. The research suggests a potential link between the molecular mechanisms involving MARCKS and the synaptic dysfunction observed in neurological diseases. MARCKS has a profound effect on already established, mature neurons. This type of altered neuronal morphology is one of the primary interests of Halpain and her laboratory. She and her colleagues have been developing and applying tools to study how synaptic connections are formed during the development of an organism, for instance, and to what extent they are altered or lost in certain diseases. The hope is that by understanding the biology of destabilization we can improve upon therapies that restore synapses.

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Confronting Autism
TSRI Professor Ed Roberts, Ph.D., has an approach to autism that is not clinically proven but which gives hope to many. The neurochemical abnormalities in autism are largely unknown but animal studies have identified several neuropeptides in the basal forebrain, hypothalamus, and brainstem that have roles in social interaction and, as such, may be hypothesized to have a role in the social abnormalities associated with autism. These neuropeptides include vasopressin and oxytocin.

Roberts intends to tackle these problems chemically by drawing on information in the public domain to develop drug-like modulators of these proteins, which belong to a superfamily known as the G protein-coupled receptors (GPCRs) as well as screening for further intervening molecules. He will also develop non-competitive ligands and will try to develop ligands that bind in an allosteric fashion, not to the site of the endogenous peptide ligand. In this way, Roberts and his colleagues can take a newer approach to ligand identification, which would offer advantages over competitive inhibition or activation.

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