Some promote the transmission of impulses while others inhibit it. The existing theory held that only two neurotransmitters, acetylcholine and nor-adrenalin, were involved in the control of internal organs. Max Bennett of Sydney University detected nerves that did not release either of these substances. Since there must be a chemical signal to relay the nerve impulse between adjacent neurons, this discovery started a race to identify the other transmitters involved. More neurotransmitters are being found Scientists have so far found hundreds of neurotransmitters, and the list is still growing.
Neurotransmitters have an important role in the normal functioning of an individual.
Research on neurotransmitters has brought greater understanding of some psychological diseases and this has led to more successful treatments. For example, we now know that manic depressive syndrome is a result of an imbalance in neurotransmitters, and we can correct the imbalance with drugs. Specific neurotransmitters and their effects The neurotransmitter serotonin plays a major role in emotions and judgement, and also sleep. Depression, suicidal behaviour, anxiety, impulsive behaviour and even eating disorders have been linked to serotonin imbalances. Recent research in Finland has suggested that murderers have very low levels of serotonin.