Beyond dopamine: a new reward circuit has been discovered

Just like space, this area of ​​the brain needs more exploration

The oldest and most well-known reward pathway is the midbrain limbic dopamine system, which consists of neurons from the ventral tegmental area (VTA) to the nucleus accumbens, which is a key structure that regulates emotion and motivation processing.

Dopamine is a neurotransmitter that is released when the brain expects a reward

In order to find ways to treat addiction and mental illness, researchers are looking for ways other than dopamine, which may play a key role in reward and reinforcement

In a paper published in the journal Nature Neuroscience , researchers in the Bruchas Lab at the University of Washington School of Medicine promoted the study of the reward pathway and found that there is another pathway besides dopamine

Dr.

In this study, the researchers found that approximately 30% of VTA cells are GABA neurons

Neurons are the basic units of the brain and nervous system.

"What we found is a unique GABAergic neuron cell that projects widely to the nucleus accumbens, but only to a specific part helps to strengthen rewards," said Raajaram Gowrishankar, co-leader of the study.

In male and female mice, the researchers showed that long-range GABA neurons from the VTA to the ventral, but not the dorsal nucleus accumbens shell, are involved in reward and reinforcement behavior

As the researchers wrote: These findings "further deepen our understanding of neural circuits, which are directly related to neuropsychiatric diseases such as depression and addiction

Ream Al-Hasani of the Center for Clinical Pharmacology and the University of Washington, one of the study’s lead authors, likened this discovery to building with Lego bricks and figuring out how to connect one piece to another

Each puzzle piece may take several years

Gowrishankar says this discovery allows scientists to understand subregions of the brain and visualize how specific neuromodulators are released during reward processing

In scientific terms, researchers can highlight heterogeneity in the brain - or differences in the brain

Gowrishankar said: "We don't think that the structure in the brain is single, which is very important

Ream Al-Hasani, Raajaram Gowrishankar, Gavin P.
Schmitz, Christian E.
Pedersen, David J.
Marcus, Sofia E.
Shirley, Taylor E.
Hobbs, Abigail J.
Elerding, Sophie J.
Renaud, Miao Jing, Yulong Li, Veronica A.
Alvarez, Julia C.
Lemos, Michael R.
Bruchas.
Ventral tegmental area GABAergic inhibition of cholinergic interneurons in the ventral nucleus accumbens shell promotes reward reinforcement .
Nature Neuroscience , 2021; DOI: 10.
1038/s41593-021-00898-2