Neurotransmitters malfunctions

IMPLICATIONS OF NEUROTRANSMITTER MALFUNCTION FROM DRUG STUDIES... 

Neurotransmitter malfunction in a disorder could be studied in animals in which ... 

At this time, however, we are not aware of any compounds selected primarily by their neuroprotection activity on rodent models that have established clinical efficacy for dementias or related neurodegenerative diseases. This may be partially explained by their priority development for stroke, and clinicians have found it is difficult or unlikely to slow the ischemia in patients if they are not treated aggressively within 3 h of the initial ischemic event. The speed of neurodegeneration in stroke (cerebral ischemia) makes it a much more difficult target for drug intervention than neurodegeneration from slower pathologies such as Alzheimer s, Parkinson s, and malfunctions in neurotransmitters. 

Neurotransmitter Function/biology Disorder if malfunction Medications used to influence this neurotransmitter... 

All related disorders are attributed to a malfunction of the basal ganglia (which contain a rich array of neurotransmitters and receptors controlling muscular movements) and of the substantia nigra (where dopamine is produced). Dopamine is one of the brain chemicals involved in the control of physical movement, and Parkinsonism is characterized by dopamine depletion. Secondary Parkinsonism, in which symptoms are of a passing nature, is due to temporary dopamine depletion, induced most commonly by antipsychotic drugs. 

Nerve cells practice a sort of recycling, in which neurotransmitters already released are reabsorbed into the presynaptic cell this process is referred to as re-uptake (see figure 3-D). Physiologic malfunctions and certain medications can either overstimulate or retard re-uptake. 

This then is the basis for modern insights into how the brain - and therefore behaviour - can be manipulated by chemical means. Clearly, as our understanding of the neuronal circuits underlying specific behaviour increases, and we understand more about the neurotransmitters functioning in such circuits, we have more chance of helping people who are suffering from various malfunctions of the nervous system (mental illnesses). It has to be accepted, however, that such information may be misused by those with malign intent. 

The field of psychiatry is predicated on the assumpt-tion that serious mental disorders result from abnormalities in the structure or function of the brain. Although no specific brain anomalies have been identified as the definitive cause of mental illness, the latest neuroscientific studies suggest that imbalances in neurochemicals—also called neurotransmitters— or malfunctions in their transportation from nerve cell to nerve cell might be responsible for the symptoms of mental illness, such as anxiety, depression, hallucinations, and delusions. Neurotransmitters include dopamine, norepinephrine, serotonin, and gamma-amino-butyric acid. Most experts believe that the causes of mental illness stem from a combination of genes (nature) and experiences (nurture). 

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