A popular theory is that schizophrenia is caused by an imbalance of neurotransmitters in the brain. Neurotransmitters (pronounced NOOR-oh-TRANZ-mit-urz) are chemicals that carry electrical messages between nerve cells. Too much of a neurotransmitter, or too little, may account for various mental disorders, including schizophrenia.
There is still no consensus (agreement) as to which, if any, of these theories is correct, or whether the disease is caused by a combination of factors.
Schizophrenia
Schizophrenia (pronounced skit-suh-FREH-nee-uh) is a psychotic disorder or group of psychotic disorders that cause a patient to lose touch with reality. It is marked by severely impaired reasoning and emotional instability and can cause violent behavior.
Schizophrenic patients are often unable to make sense of the signals they receive from the world around them. They imagine objects and events to be very different from what they really are. If untreated, most people with schizophrenia gradually withdraw from the outside world.
Exactly what schizophrenia is has been the source of considerable disagreement among psychiatrists (doctors who deal with mental disorders). There is some thought that the disease psychiatrists call schizophrenia is actually a number of different conditions classified under a single heading.
Schizophrenic patients are often unable to make sense of the signals they receive from the world around them. They imagine objects and events to be very different from what they really are. If untreated, most people with schizophrenia gradually withdraw from the outside world.
Exactly what schizophrenia is has been the source of considerable disagreement among psychiatrists (doctors who deal with mental disorders). There is some thought that the disease psychiatrists call schizophrenia is actually a number of different conditions classified under a single heading.
DNA nanotechnology
DNA nanotechnology uses the unique molecular recognition properties of DNA and other nucleic acids to create self-assembling branched DNA complexes with useful properties.[124] DNA is thus used as a structural material rather than as a carrier of biological information. This has led to the creation of two-dimensional periodic lattices (both tile-based as well as using the "DNA origami" method) as well as three-dimensional structures in the shapes of polyhedra.[125] Nanomechanical devices and algorithmic self-assembly have also been demonstrated,[126] and these DNA structures have been used to template the arrangement of other molecules such as gold nanoparticles and streptavidin proteins
Sense and antisense
A DNA sequence is called "sense" if its sequence is the same as that of a messenger RNA copy that is translated into protein.[19] The sequence on the opposite strand is called the "antisense" sequence. Both sense and antisense sequences can exist on different parts of the same strand of DNA (i.e. both strands contain both sense and antisense sequences). In both prokaryotes and eukaryotes, antisense RNA sequences are produced, but the functions of these RNAs are not entirely clear.[20] One proposal is that antisense RNAs are involved in regulating gene expression through RNA-RNA base pairing.[21]
A few DNA sequences in prokaryotes and eukaryotes, and more in plasmids and viruses, blur the distinction between sense and antisense strands by having overlapping genes.[22] In these cases, some DNA sequences do double duty, encoding one protein when read along one strand, and a second protein when read in the opposite direction along the other strand. In bacteria, this overlap may be involved in the regulation of gene transcription,[23] while in viruses, overlapping genes increase the amount of information that can be encoded within the small viral genome.
A few DNA sequences in prokaryotes and eukaryotes, and more in plasmids and viruses, blur the distinction between sense and antisense strands by having overlapping genes.[22] In these cases, some DNA sequences do double duty, encoding one protein when read along one strand, and a second protein when read in the opposite direction along the other strand. In bacteria, this overlap may be involved in the regulation of gene transcription,[23] while in viruses, overlapping genes increase the amount of information that can be encoded within the small viral genome.
Chromosome diseases:
These diseases are caused by a major error in the DNA, with an entire chromosome having a problem. Chromosomes have hundreds and thousands of genes, so these diseases have major errors in the DNA code. The most common example is down syndrome.
About inheritance and genetics:
Inheritance of Nervous system disorders refers to whether the condition is inherited from your parents or "runs" in families. The level of inheritance of a condition depends on how important genetics are to the disease. Strongly genetic diseases are usually inherited, partially genetic diseases are sometimes inherited, and non-genetic diseases are not inherited. For general information,
Inheritance and Genetics of Nervous system disorders
Genetics of Nervous system disorders: Several diseases that directly affect the nervous system have a genetic component: some are due to a mutation in a single gene, others are proving to have a more complex mode of inheritance. As our understanding of the pathogenesis of neurodegenerative disorders deepens, common themes begin to emerge: Alzheimer brain plaques and the inclusion bodies found in Parkinson disease contain at least one common component, while Huntington disease, fragile X syndrome and spinocerebellar atrophy are all 'dynamic mutation' diseases in which there is an expansion of a DNA repeat sequence. Apoptosis is emerging as one of the molecular mechanisms invoked in several neurodegenerative diseases, as are other, specific, intracellular signaling events. The biosynthesis of myelin and the regulation of cholesterol traffic also figure in Charcot-Marie-Tooth and Neimann-Pick disease, respectively. (Source: Genes and Disease by the National Center for Biotechnology)
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