Physiological Basis of Behavior. BIOLOGY background needed!!!

PSYCHOLOGICAL BASIS OF BEHAVIOR

Until recently the causes of psychological diss were not so clearly defined . Then advanced imaging techniques made it possible to see various areas of the brain and pinpoint areas that control behavior . It has been long known that the brain uses chemical messengers called neurotransmitters for signaling during its various processes . Advances in neuromedicine revealed that a lot of neurological and psychological diss have a basis in imbalances between various neurotransmitters in the brain . Diseases like Parkinson 's , Schizophrenia and Obsessive-Compulsive Dis are only a few where

administering drugs that controlled levels of various neurotransmitters in the brain could control the disease symptoms and in some cases even provide a cure Indeed , it was the discovery of these pharmacological agents that led to the discovery of newer agents that could control various neurological diss by manipulating levels of neurotransmitters

Development of various drugs for schizophrenia was done on the basis of the fact that they had the ability to block dopamine receptors . In addition it was noticed that there was also an increased number of dopamine receptors present in these patients1 . Similarly , in patients who suffered form Obsessive-compulsive dis (OCD ) an abnormality in the neurotransmitter serotonin was implicated and it was shown that drug therapy that did not affect 5-HT receptors was ineffective in the treatment of OCD6 . Parkinson 's disease like schizophrenia also is due to an abnormality in dopamine levels but in Parkinson 's dopamine levels become depleted4

Parkinson 's disease is a movement dis caused by the depletion of dopamine produced in the substantia nigra , a part of the brain that is responsible for voluntary movements of the body11 . Parkinson 's disease is a neurodegenerative disease that affects 1 of the population . Its pathophysiology involves degeneration of substantia nigra . This portion is responsible for movements in the body . Various hypotheses have been proposed concerning the causes of the disease and include genetic factors , environmental factors and viruses . Amongst these genetic factors are considered the most important and mutations in various genes have been identified that are linked to Parkinson 's disease . Genes that have been implicated are PINK-1 , DJ-1 , and LRRK2 and it is thought that in addition to hereditary viruses and toxins are thought to cause theses mutations4 . Parkinson 's disease is characterized by a fine pin-rolling tremor of the hands , rigidity , bradykinesia , an expressionless face called a mask like face and a parkinsonian gait characterized by small steps and reduced swing of the arms . Additional symptoms may be present and include difficulty in chewing and swallowing , depression , fatigue dementia , speech problems , constipation , urinary problems and orthostatic hypotension7 . Symptoms vary from patient to patient and can also have drastic emotional consequences for the patient . Diagnosis is often difficult as there are no tests available and is usually made on history and examination of the nervous system . Various treatment options are available and are mainly aimed at increasing the levels of dopamine in the brain . These include Levodopa , which is a precursor of...