University team find for the first time when and why dopamine releasing cells in the forebrain are activated

A research team from the Department of Biology has discovered for the first time both when and why the particular cells in the brain that affect movement are active – after examining transparent zebrafish.

The team, led by Dr Jonathan McDearmid, investigates how dopamine, a neurochemical secreted by nerve cells (neurons) in the brain, influences neuronal networks in the spinal cord that control motor behaviour.

He said: “Our understanding of dopamine function is largely derived from the study of dopamine-releasing neurons that are located within the midbrain, a structure located near to the base of the brain. However, vertebrates, including humans, also possess a cluster of dopamine-containing neurons in the forebrain.

“Unlike their midbrain counterparts, these neurons extend projections to the spinal cord, a region that is dedicated to the production of motor behaviours (such as walking and swimming). We know relatively little about the role this forebrain population plays in regulating behaviour: the main aim of our study was to address this problem.”

The Leicester team was able to overcome this problem by examining hatchling zebrafish which are transparent and lack bone tissue, which makes the brain accessible to study. Based on this study, Dr McDearmid said that to date, researchers had not been able to get such clear insights into the inner workings of the brain.

The research is important as it helps scientists to better understand the role that dopamine plays in controlling behaviour. In addition, dopaminergic drugs that are used to treat neurological disorders such as Schizophrenia often cause motor side-effects which could be mediated by altered dopamine signalling in the spinal cord. Thus, a better understanding of how dopamine acts in this part of the nervous system may help inform development of new drugs that have fewer motor side effects.

Source: University of Leicester