Progress in brain research
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This chapter provides a theoretical introduction to states of consciousness and reviews neuroscientific investigations of meditation. The different states of consciousness consist of four mental states, i.e., cancalata (random thinking), ekagrata (non-meditative focusing), dharna (focused meditation), and dhyana (meditation) as defined in yoga texts. Meditation is a self-regulated mental process associated with deep relaxation and increased internalized attention. ⋯ Focused meditation practice involves awareness on a single object and open monitoring meditation is a non-directive meditation involved attention in breathing, mantra, or sound. Therefore, results of few empirical studies of advanced meditators or beginners remain tentative. This is an attempt to compile the meditation-related changes in electrophysiological and neuroimaging processes among experienced and novice practitioners.
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Depression and anxiety are psychiatric diagnoses commonly associated with low quality of life and low percentage of responsiveness by patients treated with currently available drugs. Thus, research into alternative compounds to treat these disorders is essential to guarantee a patient's remission. The last decade has witnessed a revamped interest for the application of psychedelic medicine for the treatment of mental disorders due to anecdotal reports and clinical studies which show that low doses of d-lysergic acid diethylamide (LSD) and psilocybin may have antidepressant effects. ⋯ LSD, belonging to the category of "classic halluginogens," interacts with the 5-HT system through 5HT1A, and 5HT2A receptors, with the DA system through D2 receptors, and indirectly also the glutamatergic neurotransmission thought the recruitment of N-methyl-d-aspartate (NMDA) receptors. Randomized clinical studies have confirmed its antidepressant and anxiolytic effects in humans. Thus, in this chapter, we will review the pharmacology of psychedelic drugs, report the most striking clinical evidence which substantiate the therapeutic potentials of these fascinating compounds in mood disorders, and look into the horizon of where psychedelic medicine is heading.
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This chapter is an introduction to the volume "Psychedelic Neuroscience" of Elsevier's Progress in Brain Research addressing the neurobiological mechanisms of psychedelic drugs, the resulting changes in brain activity and integration of traditional viewpoints. As the field is relatively new, there are discrepancies in the literature related to classification, composition and effects of the various psychedelics. Currently, psychedelics are grouped according to their neuro-receptor affinities into classic and atypical psychedelics, each with individual treatment potentials and abilities to elicit potent acute experiences and long-lasting changes in neurobiology through concurrent activation of several neuromodulatory systems. ⋯ The term "psychedelic" means mind-revealing and psychedelics have exceptional anti-amnesic effects and are able to "make conscious" that which was previously unconscious through changes in brain "state," but also there is growing evidence which demonstrates the role of epigenetic mechanisms. This supports traditional therapeutic use of psychedelics to heal ancestral trauma. Details of these mechanisms are provided along with suggestions for further research.
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Depending on its nature, duration, and intensity, stress can exert potent and bidirectional modulatory effects on pain, either reducing pain (stress-induced analgesia) or exacerbating it (stress-induced hyperalgesia). The descending pain pathway has been implicated in both stress-induced analgesia and stress-induced hyperalgesia. ⋯ Here we review the evidence for a key role of the endogenous opioid system in stress-induced modulation of pain in rodents and humans. Understanding the neurobiological mechanisms underlying opioidergic regulation of stress-pain interactions may help in identifying novel therapeutic strategies for the improved treatment of comorbid pain and stress-related disorders.
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The recognition that sleep is one of the foundations of athlete performance is increasing both in the elite athlete arena as well as applied performance research. Sleep, as identified through sleep deprivation and sleep extension investigations, has a role in performance, illness, injury, metabolism, cognition, memory, learning, and mood. Elite athletes have been identified as having poorer quality and quantity of sleep in comparison to the general population. ⋯ Sleep, in particular slow wave sleep, provides a restorative function to the body to recover from prior wakefulness and fatigue by repairing processes and restoring energy. In addition, research in the general population is highlighting the importance of sleep on neurophysiology, cognitive function, and mood which may have implications for elite athlete performance. It is thus increased understanding of both the effects of sleep deprivation and potential mechanisms of influence on performance that may allow scientists and practitioners to positively influence sleep in athletes and ultimately maximize performances.