Progress in brain research最新文献

Exercise has been central to human brain evolution. Genus Homo was a nomadic species that constantly explored novel environments, which requires the encoding of new spatial and contextual patterns and the consolidation and recall of details to localize potential food and avoid danger, functions associated with the hippocampus. Interestingly, no primates other than humans run long distances over extended periods using aerobic metabolism, a capacity described as endurance running (ER). It has been hypothesized that ER capacity may have had relevant effects on the evolution of brain structure and cognition in the genus Homo. Paradoxically, modern humans have become sedentary and no longer need to run for food or survival. The lack of exercise in the population has increased the risk of brain disorders. Studies in human and animal models show that exercise elicits functional and structural changes throughout the brain, which may serve as a mechanism to counteract the changes induced by aging and reduced physical activity. Here, we describe the cortico-hippocampal circuitry and summarize evidence from human and animal models of aging-induced and exercise-induced changes in cortical and subcortical areas that provide polymodal information and modulatory inputs to the hippocampus, respectively. We discuss how exercise-induced plasticity in the cortico-hippocampal circuit may improve brain health.

Changes in energy homeostasis in aging have significant implications for brain health. Decreased glucose utilization efficiency, mitochondrial dysfunction, loss of metabolic flexibility, and increased oxidative stress can compromise cognitive functions and increase vulnerability to neurodegenerative diseases. Understanding these changes provides valuable insights for prevention and treatment strategies, such as dietary interventions, physical exercise, and pharmacological therapies, aimed at restoring or preserving energy homeostasis in the brain and thus improving cognitive health throughout life. This chapter explores the metabolic changes in the brain associated with aging, examining the underlying biochemical and molecular mechanisms, as well as therapeutic strategies that may alleviate the detrimental effects of brain aging.

The larger part of this chapter is concerned with the technique of drilling the cranium with a circular saw called a trepan or trephine. The terminology of the instrument is outlined. Safe use of the instrument includes probing the groove produced by its use and angling the drill so that it impinges on bone which hitherto has not been sawn through. There is then an account of how larger openings may be made by drilling multiple small holes and connecting them by means of a chisel.

Humankind demonstrates boundless curiosity, mostly expressed through the activities of a small number of individuals, whose achievements affect all members of society. The extent and distribution of pre-historic trepanation and trepanation in contemporary unsophisticated societies are reviewed. In the great majority of cases the intention of trepanation has been therapeutic, even if the understanding of underlying pathophysiology is not the same as that which scientific societies now accept. This review demonstrates variation in surgical technique. In the Atlas Mountains it was unacceptable to operate on the cranial sutures whereas in New Ireland it was not important. Pain relief was unnecessary in Melanesia because the patients were largely unconscious following injury. In South America, there was access to the coca leaf which could help with pain relief. In East Africa, one patient described the application of a powder to his wound which was thought to be for pain relief. The nature of the powder remains unknown. There were differences in the indications for trepanation. In New Britain, the operation was performed only for cases of fracture. In nearby New Ireland, epilepsy and certain forms of mental disturbance were also indications. In North and East Africa, the indication was most frequently headache following trauma. Most of these trepanations did not involve drilling, which is the main subject of this book.

Consuming coffee, a widely enjoyed beverage with caffeine, can impact the central nervous system and disturb sleep if taken too close to bedtime. Caffeine impacts sleep by slowing the onset, blocking adenosine receptors, lowering deep sleep levels, disrupting sleep patterns, and lessening rapid eye movement sleep. Although coffee can help with alertness in the morning, it may disturb sleep in the evening, particularly for individuals who are sensitive to caffeine. To enhance the quality of sleep, reduce the consumption of caffeine in the afternoon and evening, refrain from drinking caffeine before going to bed, and choose decaffeinated drinks instead. Variables such as personal reactions, ability to handle caffeine, and engagement with other compounds also influence the impact of coffee on sleep. Keeping track of how much caffeine you consume and your sleeping habits can assist in recognizing any disturbances and making needed changes. Furthermore, taking into account variables such as metabolism, age, and the timing of coffee consumption can assist in lessening the effects of coffee on sleep. In general, paying attention to the amount of caffeine consumed from different sources and consuming it at the right times can assist in preserving healthy sleep patterns even while enjoying coffee.

Cranial sutures are not of great concern to the modern neurosurgeon, except when abnormalities interfere with the skull's shape and its ability to expand during childhood. It is a commonplace that a craniotomy may cross a variety of sutures without providing any extra difficulty to the operator. The sagittal suture does remain useful as a definition of the midline of the cranium and as an indicator of the underlying sinus. Galen for reasons that are far from clear, "observed" relationships between the sutures, the meninges and the pericranium which led him to advise avoidance of any surgical proximity to the sutures. The result of this proscription was a severe limit of the access surgeons considered was appropriate and thus limited their ability to care for their patients.

Engaging in regular physical activity and establishing exercise habits is known to have multifaceted benefits extending beyond physical health to cognitive and mental well-being. This study explores the intricate relationship between exercise habits, brain imaging markers, and mental health outcomes. While extensive evidence supports the positive impact of exercise on cognitive functions and mental health, recent advancements in multimodal imaging techniques provide a new dimension to this exploration. By using a cross-sectional multimodal brain-behavior statistic in participants with different exercise habits, we aim to unveil the intricate mechanisms underlying exercise's influence on cognition and mental health, including the status of depression, anxiety, and quality of life. This integration of exercise science and imaging promises to substantiate cognitive benefits on mental health and uncover functional and structural changes underpinning these effects. This study embarks on a journey to explore the significance of multimodal imaging metrics (i.e., structural and functional metrics) in deciphering the intricate interplay between exercise habits and mental health, enhancing the comprehension of how exercise profoundly shapes psychological well-being. Our analysis of group comparisons uncovered a strong association between regular exercise habits and improved mental well-being, encompassing factors such as depression, anxiety levels, and overall life satisfaction. Additionally, individuals who engaged in exercise displayed enhanced brain metrics across different modalities. These metrics encompassed greater gray matter volume within the left frontal regions and hippocampus, improved white matter integrity in the frontal-occipital fasciculus, as well as more robust functional network configurations in the anterior segments of the default mode network. The interplay between exercise habits, brain adaptations, and mental health outcomes underscores the pivotal role of an active lifestyle in nurturing a resilient and high-functioning brain, thus paving the way for tailored interventions and improved well-being.

This study examined the association between grip strength and emotional working memory in middle-aged adults. Seventy-six males aged 40-60years (mean=48.5years, SD=5.4) participated in this cross-sectional study. They completed a muscular fitness assessment using a maximum grip strength test and emotional n-back tasks under two emotion conditions (fearful and neutral facial pictures) and two working memory loads (1-back and 2-back tasks). Hierarchical regression analyses indicated that greater muscular fitness was associated with superior working memory performance in the fearful condition in both the 1-back and 2-back tasks, after controlling for confounders. Greater muscular fitness was also associated with superior working memory performance in the neutral condition when the working memory load was high (2-back task) but not low (1-back task). These findings suggest a positive association between muscular fitness and emotional working memory and highlight the importance of maintaining muscular fitness for physical and cognitive-emotional well-being in middle-aged adults.

The physiological structure and functioning of the brain are determined by activity-dependent processes and affected by "synapse plasticity." Because chemical transmitters target and regulate synapses, exogenous chemical stimulants and transmitters can alter their physiological functions by interacting with synaptic surface receptors or chemical modulators. Caffeine, a commonly used pharmacologic substance, can target and alter synapses. It impact various biological, chemical, and metabolic processes related to synaptic function. This chapter investigates how caffeine affects fluctuations in structure and function in the hippocampus formation and neocortical structure, regions known for their high synaptic plasticity profile. Specifically, caffeine modulates various synaptic receptors and channel activities by mobilizing intracellular calcium, inhibiting phosphodiesterase, and blocking adenosine and GABA cellular receptors. These caffeine-induced pathways and functions allow neurons to generate plastic modulations in synaptic actions such as efficient and morphological transmission. Moreover, at a network level, caffeine can stimulate neural oscillators in the cortex, resulting in repetitive signals that strengthen long-range communication between cortical areas reliant on N-methyl-d-aspartate receptors. This suggests that caffeine could facilitate the reorganization of cortical network functions through its effects on synaptic mobilization.

Although recent theories of consciousness have emerged to define what consciousness is, an under-represented aspect within this field remains: time consciousness. However, the subjective passage of time is modulated by changing experiences within different situational contexts and by self-awareness. The experience of silence influences our awareness of self, space, and time, and it impacts on psychological well-being. The present review describes how self and time are influenced by different situations of silence (pure silence indoors and outdoors, the "just thinking" situation, and the combination of silence with deep relaxation). Also, the changes in time experience during a "forced" waiting situation due to the COVID-19 lockdown are presented in order to highlight the role of boredom in waiting situations and in situations in which we are alone with "our thoughts." Finally, in the context of the importance of creating silence through meditation practices, the alterations to one's sense of self and time during mindfulness meditation are reviewed. These studies are discussed within the framework of the cognitive models of prospective time perception, such as the attentional-gate model and the model of self-regulation and self-awareness.