Outline one example of an inhibitory neurotransmitter.

Introduction to the approach

The biological approach argues that there are physiological origins of many behaviours and that human beings should be studied as biological systems. Biologists have found that the relationship between biological factors and behaviour is bidirectional.

Introduction to the topic

Neurotransmission is the process by which nerve cells send electrochemical messages to the brain so that people can respond to stimuli. The messages reach the nerve ends as an electrical message and then are transmitted through the synapse, via neurotransmitters as chemical messengers. Every neuron has a certain threshold of excitation and if this excitation exceeds the threshold, the neurotransmitter is fired. After the release of neurotransmitters back into the synapse, three things can occur - they could be metabolised, pulled back through re-uptake or reach the postsynaptic membrane and bind to one of its receptors. All neurotransmitters are broadly divided into two groups - excitatory and inhibitory.

Introduction to the subtopic

Inhibitory neurotransmitters stops the impulse, preventing it from crossing the synapse. They produce calming effects on the brain. When any of these neurotransmitters are out of optimal ranges, it may cause behavioural malfunctions and mental disorders.

Thesis

This response will show the effect of serotonin; an inhibitory neurotransmitter on human behaviour. Serotonin regulates sleep cycles and maintains a stable mood. It is known as the ‘happy chemical’. Evidence by Crockett et al will be used to show the effect of serotonin on prosocial behavior in humans.

Crockett et al (2010) - Aim + Participants

To explore the effect of serotonin on moral judgement and pro-social behaviour on a volunteer sample of healthy 13 males and 17 females with a mean age of 26 years. All participants did both the conditions of the independent variable, making this a repeated measures design experiment.

Crockett et al (2010) - Method

In the first condition the participants were given a dose of SSRI and were given a placebo in the second. Following this the participants were given a series of moral dilemmas that involved choosing between a utilitarian outcome (saving 5 lives) and aversive harmful actions (killing an innocent person). There were two aversive harmful actions, either push a person onto the train in order to stop it (personal) or push a lever to divert the train to kill only one person instead of five (impersonal).

Crockett et al (2010) - Results

Results showed that citalopram only influenced judgement in the emotionally salient personal scenarios, which evoke strong emotional reactions relative to impersonal scenarios. After receiving a dose of the drug participants were less likely to push the man in the personal scenario. Therefore, one can conclude that serotonin reduces acceptability of personal harm and promotes prosocial behaviour.

Link

The results of the study clearly demonstrate that when the levels of serotonin were increased in the participants with citalopram they were more likely to show prosocial behaviour, thus showing the effect of an inhibitory neurotransmitter on human behaviour.

Conclusion

Therefore in conclusion it can be said that a strong correlation between brain and behaviour explained through the process of neurotransmission can be claimed. The evidence provided from the study further reiterates the underlying principle that behaviour is a product of physiology and humans can largely be studied as biological units.