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July 5, 2024 — Scripps Research, La Jolla, CA
Decisions about whether to take that first bite of food or walk away are influenced by a complex network of brain cells, according to a groundbreaking study published in Molecular Psychiatry on July 4, 2024. Researchers at Scripps Research have pinpointed a group of neurons in the parasubthalamic nucleus (PSTN) that plays a crucial role in regulating when an animal begins eating.
The study, led by Dr. Jeff Dunning and senior author Dr. Candice Contet, used advanced techniques to selectively manipulate PSTN cells in mice, particularly focusing on those activated during binge-eating episodes. By controlling these neurons, the team observed significant changes in the mice’s eating and drinking behaviors.
“We aimed to understand how these cells influence appetite and feeding decisions,” said Dr. Dunning. “By activating a specific ensemble of PSTN cells, we could observe how they affected the timing of the animals’ first bite of food.”
The findings revealed that mice typically start eating quickly when food is available. However, when the PSTN cells were activated, the mice took longer to begin eating and surprisingly drank water more quickly. This delayed eating and increased water consumption were linked to the role of these neurons in the early stages of hunger-driven decision-making.
“Our study shows that the PSTN neurons involved in binge-eating can guide the timing of eating and influence water intake,” Dr. Dunning explained. “The effect on water consumption is intriguing and might be connected to prandial thirst — a phenomenon where thirst increases with the anticipation of eating.”
Further analysis revealed that different subsets of PSTN cells had distinct functions. Some were responsible for delaying eating, while others encouraged the consumption of sweet foods. This complexity suggests that PSTN neurons have diverse roles in managing feeding behaviors and responses.
Dr. Contet noted the significance of these findings: “Previous research showed that PSTN activity could limit food intake, but our study is the first to demonstrate that these neurons can control the initiation of feeding and even promote the consumption of ‘treats.'”
The researchers believe their findings could have implications for understanding and treating eating disorders, where individuals may struggle with either excessive or insufficient control over their eating behaviors. The team is also exploring similar mechanisms in the context of substance abuse disorders.
This study, titled “The parasubthalamic nucleus refeeding ensemble delays feeding initiation and hastens water drinking,” was conducted with support from the National Institutes of Health (grants AA026685, AA027636, AA006420, AA027372, and AA007456).
In addition to Drs. Dunning and Contet, the research team included Catherine Lopez, Colton Krull, Max Kreifeldt, Maggie Angelo, Leeann Shu from Scripps Research, and Charu Ramakrishnan and Karl Deisseroth from Stanford University.
