Progress in brain research最新文献

Dementia poses a significant challenge to global health. This chapter reviews current literature to investigate the potential protective effects of happiness and positive emotions against dementia. Studies suggest that individuals experiencing higher levels of happiness and frequent positive emotions may exhibit lower risks of developing dementia. Mechanisms proposed include the role of positive emotions in stress reduction, which could mitigate neurodegenerative processes. In addition, recent studies have begun exploring the impact of positive psychological states, such as happiness and positive emotions, on cognitive health. Furthermore, positive psychological states have been linked to healthier lifestyle choices, including physical activity and social engagement, which are known to support cognitive function. Despite promising findings, challenges remain in establishing causal relationships and elucidating specific neurobiological pathways. Future research should focus on longitudinal studies with diverse populations to clarify these relationships and inform effective interventions. Understanding how happiness and positive emotions influence dementia risk could lead to novel preventive strategies and improve quality of life for aging populations worldwide. This chapter summarizes the potential benefits of happiness and positive emotions in mitigating the risk of dementia, highlighting the need for further research to establish causal links and develop targeted interventions.

By 2025, the global elderly population is estimated to reach 2.1 billion, likely leading to an increased prevalence of neuropsychiatric disorders. This brings attention to the drawbacks of pharmacological therapies, which primarily manage symptoms and often entail significant side effects. Evidence suggests that physical activity (PA) represents a non-drug strategy that can positively influence cognitive and neurological health through various molecular pathways, including brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), neuroplasticity, neurogenesis, and the regulation of neurotransmitters. Aerobic exercise, resistance training, and mind-body practices have been investigated to enhance cognitive functions, including memory, executive processing, and attention, while simultaneously mitigating neuroinflammation and oxidative stress. These benefits are linked with increased hippocampal volume, synaptic plasticity, and BDNF levels. This chapter aims to discuss the neurobiological processes responsible for the effects of PA while also promoting public health strategies that support healthy cognitive aging and alleviate the burden of neuropsychiatric disorders.

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.

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.

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.

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.

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.

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.