A molecular and functional dissection of the GABAergic neuronal diversity in the ventral tegmental area

Abstract

The ventral tegmental area (VTA) is a region in the brain that is involved in various behaviours and disorders, such as addiction. In the brain, different classes of neurons exist. These neurons are connected to each other in neuronal networks. The VTA contains dopamine neurons, which release dopamine. It also contains GABAergic neurons that ‘inhibit’ the activity of other neurons, meaning they make the neurons they are connected to less active. There are many subtypes of GABAergic neurons, which all express a different combination of genes and make connections to a variety of other neurons in and outside of the VTA. At the moment, not much is known about exactly how many subtypes of GABAergic neurons exist in the VTA and what the role of each GABAergic subtype is in different behaviours. We here review the currently available literature on GABAergic neurons in the VTA, and attempt to find links between gene expression, connectivity and behaviour, in order to identify different subtypes of GABAergic neurons. Distinguishing these GABAergic subtypes will allow researchers to study more specifically each subtype of GABAergic neurons and which connections they make. This will eventually improve our understanding of the role of GABAergic neurons in health, and give us insights in mechanisms of disease, such as how people get addicted or depressed.