Oral microbiota dysbiosis and altered salivary cortisol levels have been linked to depression and anxiety. Given that bacterial transmission can occur between spouses, this study aimed to investigate whether the transmission of oral microbiota between newlywed couples mediates symptoms of depression and anxiety.
Depression is a mental health disorder characterized by a recurrent or persistent sadness and a loss of interest in activities that were previously deemed pleasurable, sometimes accompanied by changes in sleep, appetite and perceived energy levels. One of the most debilitating types of depression is major depressive disorder (MDD), which entails a pervasive low mood for a prolonged time, which in turn adversely impacts people’s ability to engage in daily activities.
As depression is estimated to be experienced by approximately 3.5% of people worldwide, understanding its neurophysiological underpinnings and its characteristic brain signatures is of utmost importance. Past studies have linked depression, particularly MDD, to structural changes in a brain region known as the medial temporal lobe, which has been implicated in the formation and retrieval of memories, as well as in emotional processing and decision-making.
Researchers at Aachen University and Forschungszentrum Jülich GmbH recently carried out a study aimed at exploring the link between the structure of a specific part of the MTL, namely the parahippocampal cortex (PHC), and MDD. Their paper, published in Translational Psychiatry, suggests that the thickness of the PHC is an indicator of both MDD and neuroticism, a psychological trait marked by a pronounced tendency to feel negative emotions (e.g., anxiety, guilt, anger, etc.).
Researchers led by the University of Geneva and École Polytechnique Fédérale de Lausanne report that neural anticipation of virtual infection triggers an immune response through activation of innate lymphoid cells.
Innate lymphoid cells (ILCs) are a type of immune cell crucial for early immune responses. They do not rely on antigen recognition like adaptive immune cells but respond quickly and effectively to various inflammatory signals and pathogen-associated cues, playing an essential role in early defense.
Protecting the body from pathogens typically involves a multitude of responses after actual contact. An anticipatory biological immune reaction to an infection had not been previously demonstrated.
New research published in Proceedings of the National Academy of Sciences (PNAS) finds that prolonged and/or repeated exposure to gamma-aminobutyric acid (GABA) anesthetic agents (sevoflurane, propofol) for infants in the first two months of life resulted in an accelerated maturation of brain electrical activity patterns evoked by visual stimuli when recorded at 2–5 months of age, compared to infants who did not have early general anesthesia exposure.
These findings may suggest the use of non-GABA-active anesthetics for the newborn age-range. To address such concerns, a large multicenter clinical trial (called TREX) is currently in progress using a combination of anesthetic agents in order to minimize exposure to GABA-active anesthetics.
The paper is the fourth in a series emerging from a prospective longitudinal study known as the General Anesthesia and Brain Activity (GABA) Study, led by researchers at Boston Children’s Hospital and Northeastern University.
The cerebral cortex processes sensory information via a complex network of neural connections. How are these signals modulated to refine perception? A team from the University of Geneva (UNIGE) has identified a mechanism by which certain thalamic projections target neurons and modify their excitability.
The work, published in Nature Communications, reveals a previously unknown form of communication between two regions of the brain, the thalamus and the somatosensory cortex. It could explain why the same sensory stimulus does not always elicit the same sensation and open up new avenues for understanding certain mental disorders.
The same sensory stimulus can be perceived clearly at times, and remain vague at others. This phenomenon can be explained by the way the brain integrates stimuli. For example, touching an object outside our field of vision may be enough to identify it…or not.
Using mathematical analysis of patterns of human and animal cell behavior, scientists say they have developed a computer program that mimics the behavior of such cells in any part of the body. Led by investigators at Indiana University, Johns Hopkins Medicine, the University of Maryland School of Medicine and Oregon Health & Science University, the new work was designed to advance ways of testing and predicting biological processes, drug responses and other cell dynamics before undertaking more costly experiments with live cells.
With further work on the program, the researchers say it could eventually serve as a “digital twin” for testing any drug’s effect on cancer or other conditions, gene environment interactions during brain development, or any number of dynamic cellular molecular processes in people where such studies are not possible.
Funded primarily by the Jayne Koskinas Ted Giovanis Foundation and the National Institutes of Health, and leveraging prior knowledge and data funded by the Lustgarten Foundation and National Foundation for Cancer Research, the new study and examples of cell simulations are described online July 25 in the journal Cell.
Johns Hopkins University researchers have grown a novel whole-brain organoid, complete with neural tissues and rudimentary blood vessels—an advance that could usher in a new era of research into neuropsychiatric disorders such as autism.
“We’ve made the next generation of brain organoids,” said senior author Annie Kathuria, an assistant professor in JHU’s Department of Biomedical Engineering who studies brain development and neuropsychiatric disorders. “Most brain organoids that you see in papers are one brain region, like the cortex or the hindbrain or midbrain. We’ve grown a rudimentary whole-brain organoid; we call it the multi-region brain organoid (MRBO).”
The research, published in Advanced Science, marks one of the first times scientists have been able to generate an organoid with tissues from each region of the brain connected and acting in concert. Having a human cell-based model of the brain will open possibilities for studying schizophrenia, autism, and other neurological diseases that affect the whole brain—work that typically is conducted in animal models.
Several studies have indicated that forgotten memories may not be as irretrievable as once thought. Memory appears to be closely tied to the context in which it was encoded. Consequently, remembering smells, sounds and other environmental cues, as well as any feelings experienced during the time the memory was formed can help to recall the memory. However, these memory studies have not sufficiently determined how this kind of contextual memory recall is forgotten after recall.
As most people are aware, retrieving a memory normally becomes more and more difficult as time goes on, but the rate of forgetting actually declines over time in a nonlinear manner due to ongoing memory consolidation. In other words, humans will forget an event at a faster rate within the first few days or weeks, and then the forgetting levels off somewhat and less of the memory is lost over longer time periods.
In a new study, published in the Proceedings of the National Academy of Sciences, a group of German scientists sought to determine if retrieving memories with “mental time travel” can restore the retrieval and forgetting rate to how they were shortly after encoding. To do this, they recruited 1,216 participants to undergo two different memory experiments.
