The Brain’s Hidden Patterns: Uncovering the Secret to Flexibility and Stability

For decades, scientists believed that the brain used a single, shared transmission site for all types of plasticity. However, a groundbreaking study from researchers at the University of Pittsburgh has challenged this assumption, revealing that the brain employs distinct transmission sites to achieve different types of plasticity.

The study, published in Science Advances, offers a deeper understanding of how the brain balances stability with flexibility – a process essential for learning, memory, and mental health. By uncovering the hidden patterns of the brain’s transmission sites, researchers hope to shed light on the underlying mechanisms that govern our thoughts, emotions, and behaviors.

Neurons communicate through synaptic transmission, where one neuron releases chemical messengers called neurotransmitters from a presynaptic terminal. These molecules travel across a microscopic gap called a synaptic cleft and bind to receptors on a neighboring postsynaptic neuron, triggering a response.

Traditionally, scientists believed that spontaneous transmissions (signals that occur randomly) and evoked transmissions (signals triggered by sensory input or experience) originated from one type of canonical synaptic site and relied on shared molecular machinery. However, the research team led by Oliver Schlüter discovered that the brain instead uses separate synaptic transmission sites to carry out regulation of these two types of activity.

The study focused on the primary visual cortex, where cortical visual processing begins. The researchers expected spontaneous and evoked transmissions to follow a similar developmental trajectory, but instead found that they diverged after eye opening.

As the brain began receiving visual input, evoked transmissions continued to strengthen. In contrast, spontaneous transmissions plateaued, suggesting that the brain applies different forms of control to the two signaling modes. To understand why, the researchers applied a chemical that activates otherwise silent receptors on the postsynaptic side, causing spontaneous activity to increase while evoked signals remained unchanged.

This division likely enables the brain to maintain consistent background activity through spontaneous signaling while refining behaviorally relevant pathways through evoked activity. This dual system supports both homeostasis and Hebbian plasticity – the experience-dependent process that strengthens neural connections during learning.

“Our findings reveal a key organizational strategy in the brain,” said Yue Yang, a research associate in the Department of Neuroscience and first author of the study. “By separating these two signaling modes, the brain can remain stable while still being flexible enough to adapt and learn.”

The implications could be broad. Abnormalities in synaptic signaling have been linked to conditions like autism, Alzheimer’s disease, and substance use disorders. A better understanding of how these systems operate in the healthy brain may help researchers identify how they become disrupted in disease.

“Learning how the brain normally separates and regulates different types of signals brings us closer to understanding what might be going wrong in neurological and psychiatric conditions,” said Yang.

The study published in Child Development found that singing to infants can significantly boost their mood. This is according to researchers at Yale University’s Child Study Center, who conducted an experiment where parents were encouraged to sing more frequently to their babies. The results showed a measurable improvement in infants’ moods overall, compared to those in the control group.

The study included 110 parents and their babies, most of whom were under four months old. Parents were randomly assigned into two groups: one group received encouragement to sing more frequently by teaching them new songs, providing karaoke-style instructional videos, and sending weekly newsletters with ideas for incorporating music into daily routines. For four weeks, these parents received surveys on their smartphones at random times throughout the day.

The researchers found that parents were successfully able to increase the amount of time they spent singing to their babies. Not only did the parents sing more frequently, but they also chose to use music especially in one context: calming their infants when they were fussy.

“This simple practice can lead to real health benefits for babies,” said Eun Cho, postdoctoral researcher at the Yale Child Study Center and co-first author of the study. “We show that singing is something that anyone can do, and most families are already doing.”

The researchers believe that the benefits of singing may be even stronger than the current study shows, especially in a family that does not already rely on music as a way of soothing their infants.

A follow-up study, “Together We Grow,” will investigate the impact of infant-directed singing over an eight-month period. The Child Study Center researchers are currently enrolling parents and babies under four months old in this study to further explore the benefits of singing.

The findings have implications for alleviating stress or conditions such as postpartum depression in the long term, and may also show benefits beyond mood in infants, such as improved sleep.

As Samuel Mehr, an adjunct associate professor at the Child Study Center and director of The Music Lab, said, “Our understanding of the evolutionary functions of music points to a role of music in communication. Parents send babies a clear signal in their lullabies: I’m close by, I hear you, I’m looking out for you — so things can’t be all that bad.”

The Pace of Aging, a newly refined method for measuring the rate at which individuals experience age-related health decline, offers researchers and policymakers a powerful tool for predicting risks associated with aging, including chronic illness, cognitive impairment, disability, and mortality. Developed by Columbia University Mailman School of Public Health researchers, this approach quantifies how quickly individuals and populations experience age-related health decline.

The existing toolkit for population health research on aging did not distinguish differences caused by early-life factors from those caused by ongoing changes in people’s bodies due to aging. The findings from the study published in Nature Aging highlight the importance of this new method.

“Our Pace of Aging method is an essential approach for understanding population aging,” explained Arun Balachandran, PhD, a postdoctoral researcher at the Columbia Aging Center and lead author of the study. “Our existing toolkit doesn’t include methods that can separate out the legacies of early life from the changes caused by aging.”

Daniel Belsky, PhD, associate professor of Epidemiology at Columbia Mailman School and member of the Robert N. Butler Columbia Aging Center, elaborated on this point: “We developed the Pace of Aging method to evaluate the effectiveness of interventions targeting the biology of aging. The new approach introduced in this paper is designed to do the same for social policies and public health programs.”

The researchers analyzed data from two large-scale studies: the U.S. Health and Retirement Study (HRS) and the English Longitudinal Study of Aging (ELSA). These long-term studies follow adults aged 50 and older, along with their spouses, collecting detailed information on health, cognition, socioeconomic status, and family dynamics.

The new approach makes use of data from dried blood spots, physical exams, and performance tests given to participants in their homes at up to three timepoints over eight-year follow-up intervals. The researchers examined the Pace of Aging in 19,045 participants who contributed data over 2006-2016, with additional follow-up to determine disease, disability, and mortality through 2022.

In the US study, the Pace of Aging was measured from C-reactive protein (CRP), Cystatin-C, glycated hemoglobin (HbA1C), diastolic blood pressure, waist circumference, lung capacity (peak flow), balance, grip strength, and gait speed. The researchers found that their method can measure important variability in the pace of aging in older people with a relatively limited set of measurements.

“Our findings establish that we can measure important variability in the pace of aging in older people with a relatively limited set of measurements,” said Belsky. “Our findings open up possibilities to study pace of aging in cohorts around the world.”

The researchers also found signs of accelerated aging in people with lower levels of education and reported differences in aging trajectories across population subgroups. Originally developed using data from the Dunedin Study, a longitudinal study of individuals born in 1972-73, the initial Pace of Aging tool focused on changes from young adulthood through midlife.

The newly adapted method extends its utility to population-based studies of aging, offering planners and policymakers a valuable resource for monitoring and improving population health and longevity. “Beyond medicine and gerontology, this work has important implications for sociology and economics,” added Belsky.

“It can help us understand how life transitions – such as retirement, caregiving, and bereavement – affect the aging process and support the development of more effective public health and social policies.” The researchers highlighted that the differences in aging speed found were not just statistically significant but meaningful, with people aging faster much more likely to get sick, become disabled, or die sooner.

The study was supported by National Institutes of Health grants R01AG061378, T32AI114398, and U01AG009740; the Russel Sage Foundation; BioSS Grant 1810-08987; and the Robert N. Butler Columbia Aging Center.