G Protein Coupled Receptor Function in Bipolar Disorder Type Research Proposal

G Protein Coupled Receptor Function in Bipolar Disorder Type - Research Proposal Example The paper tells that bipolar disorder is a complex psychiatric disease having genetic basis. This is mainly due to the chemical imbalance bipolar disorder affects up to 3 percent of the total population. According to World Health Organization report of 2001, bipolar disorder stands fifth for the cause of disability among the adults. Male and female are affected by this disease in equal ratio. This disease can develop at any age and takes several years for complete development in the individual. Bipolar disorder is a family disease. It is the combination of stigma, disability and cognitive impairment. Depression causes the emergence of this disease in people. The lacks of neurotransmitters at the brain are found to be associated with the bipolar disorder. The symptoms of bipolar disorder are elevated mood, different thoughts, pressurized speech, less need for sleep, increase in the goal directed activity, poor judgment and tangential speech. Bipolar disorder is associated with long te rm morbidity, co morbidity, disability and increased mortality rates due to suicide accidents etc. G- Protein coupled receptors (GPCRs) comprises a super family of cell membrane receptors with many common features having a single polypeptide with many membrane spanning domains. GPCRS have seven transmembrane proteins with hetero-trimers. There is an alpha sub unit which binds to guanine nucleotides. GPCRs play important role in the development and regulation of cellular physiology. They participate in the diversified physiological functions and are the targets of many drugs. The ligands are very diverse such as amides, peptides, proteins, lipids, nucleotides and photons. GPCRs have many alternating signalling pathways and interact mainly with the proteins such as arrestins and kinases. 90% of the nonsensory GPCRs are present in the brain and they play many important neuronal functions. There are five dopamine receptors D1, D2, D3, D4 and D5 divided into two groups based on the seque nce and functional similarities. D1 like (D1 and D5) and D2 like (D2, D3, D4). (Pompili et al., 2011).These dopamine receptors are believed to be involved in the brain disorders such as Parkinson’s disease, schizophrenia, addiction, and Huntington’s disease. The D4 receptor is activated by the dopamine receptor present in the brain. The mutations in the GPCRs have resulted in a number of diseases in human. The mutations may be activating mutations or inactivating mutations. D1, D2 are shown to have a greater interaction with the bipolar disorder. All the antipsychotic drugs block the dopamine D2 receptors and are