Findings Suggest Young People May Suffer Long-Term Consequences, Particularly in the Area of ​​Cognitive Flexibility — ScienceDaily

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While food insecurity is a problem for a growing segment of the U.S. population — further exacerbated by the coronavirus pandemic — few studies have looked at the effect feasting or starvation has on the developing brain regardless of other factors that contribute to adversity.

A new study by neuroscientists at the University of California, Berkeley simulated the effects of food insecurity in juvenile mice and found lasting changes later in life.

“We show that irregular access to food in late childhood and early adolescence affects learning, decision-making, and dopamine neurons in adulthood,” said Linda Wilbrecht, professor of psychology at UC Berkeley and member of the Helen Wills Neuroscience Institute.

A key difference in behavior involved cognitive flexibility: the ability to generate new solutions when the world changes.

“Reward-seeking mice can be inflexible, sticking to a single strategy even when it no longer yields a reward, or they can be flexible and quickly try new strategies. We found that the stability of the The food supply mice had when they were young governed their flexibility in different conditions when they were adults,” she said.

Epidemiological studies have linked food insecurity in children and adolescents to weight gain later in life, as well as learning problems and lower scores in math, reading and vocabulary. But these studies are confounded by other poverty-related issues, such as maternal depression and environmental stressors. The new study was designed to examine the developmental and behavioral impacts of food insecurity in a controlled setting not possible with human subjects.

The study has implications for humans. Policymakers are recognizing the importance of good nutrition from infancy through high school, with federally funded free or discounted breakfast and lunch programs available in schools across the states. United. The federal Supplemental Nutrition Assistance Program (SNAP) also provides benefits to supplement the food budget of families in need. For families living paycheck to paycheck, these food programs have demonstrated effects, including improved academic performance and graduation rates.

But there may be times when children cannot access food programs, such as during summer vacation. Programs can also inadvertently create a cycle of feast and famine when benefits are distributed with weeks between payments, potentially leaving poor families unable to afford food at the end of each payment cycle. According to a recent report by the United States Department of Agriculture, 6.2% of households with children – 2.3 million households in total – were food insecure in 2021.

“I think we need to understand that even transient food insecurity is important, the brain doesn’t just catch up later. Food insecurity can have long-term impacts on a person’s brain function,” said Wilbrecht. “The ability to learn and make decisions is something that develops during childhood and adolescence, and we see how these essential skills are affected by access to food. Access to food is something we can address in this county. Food and benefits programs exist, and we can improve them by making access to benefits or food more reliable and consistent. Supporting brain development is a good reason to support food programs.

The research, conducted with UC Berkeley faculty members Helen Bateup, Stephan Lammel, and their lab colleagues, will appear in an upcoming print edition of the journal. Current biology. It went live on July 20.

Flexibility in case of changing rules

Wilbrecht and his colleagues, including Robert Wood Johnson Foundation health and society researcher Ezequiel Galarce, mimicked human food insecurity in mice by delivering food on an irregular schedule while leaving enough food behind. to maintain a safe body weight. This diet started a week before the onset of puberty in mice, which is equivalent to the end of childhood in humans, and continued for 20 days until the equivalent of the end of adolescence in mice. Another group of mice were offered food whenever they wanted.

They then tested cognition in adulthood using foraging tasks where the mice searched for rewards in a changing environment. For example, one behavior – in this case, learning what smell led to Honey Nut Cheerios – may be successful for a short time, but not forever. A second smell now predicted where the reward was hidden.

Well-nourished, food-insecure mice were tested as adults in certain and uncertain contexts, with notable differences in cognitive flexibility. Food-insecure mice were more flexible in uncertain situations than well-nourished mice, while well-nourished mice were more flexible in more stable situations.

“You would have to test in the field to see how these different flexibility profiles affect survival,” she said. “The results are nuanced, but hopeful, as we identify both gain and loss of function in learning and decision-making that are brought about by the experience of scarcity.”

While the effect of food insecurity on cognition in male mice was robust, female mice showed no effect on cognition.

“This is one of the most robust behavioral effects we’ve ever seen when modeling adversity,” Wilbrecht said.

Food insecurity, however, had other distinctly negative effects in female mice. Women who were food insecure when growing up tended to become overweight when given unrestricted food as adults, which is mirrored in humans who grew up food insecure. Male mice showed no such effect.

Doctoral student Wan Chen Lin and researchers from Bateup and Lammel labs also looked at the brain’s reward network, which is governed by the neurotransmitter dopamine, and found changes there in male mice as well.

“We found that neurons of the dopamine system, which are essential for learning, decision-making and reward-related behaviors such as addiction, were significantly altered in both their inputs and outputs,” he said. said Wilbrecht. “This suggests that there are larger-scale changes to learning and decision-making systems in the brain.”

For example, researchers observed changes in the synapses of dopamine neurons that project to the nucleus accumbens and also found changes in dopamine release in the dorsal striatum. These dopaminergic neurons have been shown to play a role in learning and decision making in many other studies.

The researchers are continuing their studies on food-insecure mice to determine whether they are more susceptible to addictive behaviors in adulthood, which are associated with the dopaminergic network.

The other authors of the UC Berkeley paper are former postdoctoral fellow Polina Kosillo, former doctoral student Christine Liu, and senior scientist Lung-Hao Tai. The work was supported by the National Institutes of Health (R21 AA025172, U19NS113201) and the Robert Wood Johnson Foundation. Bateup is a Chan Zuckerberg Biohub Researcher and a Weill Neurohub Researcher.

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