Scientists have known that a region of the brain called the central nucleus of the amygdala (CeA) plays a role in behaviors related to alcohol use and consumption in general. It's been less known which precise populations of brain cells and their projections to other brain regions mediate these behaviors. Now, scientists discovered that specific neurons in the CeA contribute to reward-like behaviors, alcohol consumption in particular.
Published in the Journal of Neuroscience, this research pinpoints a specific neural circuit that when altered caused animal models to drink less alcohol.
"The fact that these neurons promote reward-like behavior, that extremely low levels of alcohol consumption activate these cells, and that activation of these neurons drive alcohol drinking in animals without extensive prior drinking experience suggests that they may be important for early alcohol use and reward," said senior author. "It's our hope that by understanding the function of this circuit, we can better predict what happens in the brains of people who transition from casual alcohol use to subsequent abuse of alcohol, and the development of alcohol use disorders."
The authors set out to investigate if a population of neurons that express a specific neuropeptide (neurotensin or NTS) contributes to reward-like behaviors and alcohol drinking. They were especially interested in these neurons in the context of inexperienced alcohol use, such as when a person first begins to drink alcohol. Also, NTS neurons are a subpopulation of other neurons in this CeA brain region that have been implicated in anxiety and fear - known as the somatostatin and corticotropin releasing factor neurons.
Using modern genetic and viral technologies in male mice, the authors found that selectively lesioning or ablating the NTS neurons in the CeA, while maintaining other types of CeA neurons, would cause the animals to drink less alcohol. This manipulation did not alter anxiety-like behavior. It also did not affect the consumption of other palatable liquids such as sucrose, saccharin, and bitter quinine solutions.
"We found that these NTS neurons in the CeA send a strong projection to the hindbrain, where they inhibit the parabrachial nucleus, near the brainstem," the senior author said.
Using optogenetics - a technique where light activates these neurons - the researchers stimulated the terminal projections of the CeA-NTS neurons in the parabrachial and found that this stimulation inhibited the neurons in the parabrachial. When the scientists stimulated this projection with a laser in one half of the animal's box, animals would spend more time where the stimulation would occur.
Animals also learned to perform a task to get the laser stimulation to turn on, and they would do this repeatedly, suggesting that they found this stimulation to be rewarding.
"Furthermore, when we stimulated this projection, animals would drink more alcohol as compared to when they had an opportunity to drink alcohol without laser stimulation," the senior author said. "In contrast to our study where we ablated the NTS neurons, laser stimulation of this parabrachial pathway also caused the animals to consume caloric and non-caloric sweetened beverages. When the animals were presented with regular food and a sweet food, however, laser stimulation did not enhance the consumption regardless of the mouse's hunger state. This suggests that different circuits may regulate the consumption of rewarding fluids and solids."
The authors of this study, hope to explore how alcohol experience may change these neurons over time.
"Would these cells respond differently after animals have been drinking high quantities of alcohol over time?" the author said. "We also want to discover which populations of neurons in the parabrachial are receiving inputs from these neurons. Fully understanding this circuit could be the key to developing therapeutics to help people with alcohol use disorders."
http://news.unchealthcare.org/news/2019/december/scientists-discover-key-neural-circuit-regulating-alcohol-consumption
https://www.jneurosci.org/content/early/2019/11/19/JNEUROSCI.1466-19.2019
Neurons regulating early alcohol consumption identified!
- 4,084 views
- Added
Edited
Latest News
In-vitro 3D culture of func…
By newseditor
Posted 15 Jun
Neural balance in the brain…
By newseditor
Posted 15 Jun
Antimalarial compounds reli…
By newseditor
Posted 15 Jun
3D imaging of whole human b…
By newseditor
Posted 14 Jun
Reading pleasure and pain f…
By newseditor
Posted 14 Jun
Other Top Stories
Gene mutations linking intracranial aneurysms identified!
Read more
A missing genetic switch at the origin of malformations
Read more
A genetic mutation confirmed as predisposing factor in chronic obst…
Read more
Rare gene variants of eczema identified!
Read more
How bone-bordering cells may help shape a skull
Read more
Protocols
Bioengineered human colon o…
By newseditor
Posted 14 Jun
Development of an efficient…
By newseditor
Posted 12 Jun
A co-culture system of macr…
By newseditor
Posted 10 Jun
Analysis of 3D pathology sa…
By newseditor
Posted 08 Jun
Long-term expandable mouse…
By newseditor
Posted 07 Jun
Publications
NRG1-ErbB4 signaling in the…
By newseditor
Posted 15 Jun
HPV integration and cervica…
By newseditor
Posted 15 Jun
Cerebral tau pathology in c…
By newseditor
Posted 15 Jun
Cerebral tau pathology in c…
By newseditor
Posted 15 Jun
Synthetic biodegradable mic…
By newseditor
Posted 15 Jun
Presentations
Myelin plasticity in the ve…
By newseditor
Posted 10 Jun
Hydrogels in Drug Delivery
By newseditor
Posted 12 Apr
Lipids
By newseditor
Posted 31 Dec
Cell biology of carbohydrat…
By newseditor
Posted 29 Nov
RNA interference (RNAi)
By newseditor
Posted 23 Oct
Posters
A chemical biology/modular…
By newseditor
Posted 22 Aug
Single-molecule covalent ma…
By newseditor
Posted 04 Jul
ASCO-2020-HEALTH SERVICES R…
By newseditor
Posted 23 Mar
ASCO-2020-HEAD AND NECK CANCER
By newseditor
Posted 23 Mar
ASCO-2020-GENITOURINARY CAN…
By newseditor
Posted 23 Mar