The Journal of neuroscience : the official journal of the Society for Neuroscience
February 24, 2021
Annalotta Scheinin, Oskari Kantonen, Michael Alkire et al.
92 citations
Consciousness often persists even when unresponsiveness occurs. In two experiments involving 76 healthy males, brain activity was measured during varying states of consciousness induced by propofol and dexmedetomidine (n = 39) and during sleep-deprived wakefulness and non-REM sleep (n = 37). Most participants reported internally generated experiences while unresponsive. Key brain regions, including the thalamus and cingulate cortices, were found critical for consciousness, showing consistent activity patterns regardless of anesthetic type or sleep state, highlighting a core network essential for conscious awareness.
March 30, 2023
Jussi Jylkkä, Aleksi Hupli, Aleksandra Nikolaeva et al.
preprint
Medical cannabis and opioids are perceived as equally effective at reducing pain intensity, but medical cannabis additionally improves emotion, functionality, and overall sense of wellbeing. A survey of Finnish chronic pain patients compared 40 medical cannabis users with 161 opioid users. After matching for confounding factors, medical cannabis users scored higher on positive emotional effects (large effect) and holistic positive effects (medium effect), with no difference in negative side effects. This supports the idea that medical cannabis alters the pain experience more holistically rather than only targeting pain intensity.
Journal of Cannabis Research
November 9, 2023
Jussi Jylkkä, Aleksi Hupli, Aleksandra Nikolaeva et al.
Medical cannabis and opioids are perceived as equally effective at reducing pain intensity, but medical cannabis additionally improves emotion, functionality, and overall wellbeing. A retrospective survey of Finnish chronic pain patients (40 medical cannabis users, 161 opioid users) used propensity score matching and factor analysis to compare phenomenological effects. The medical cannabis group scored higher on Positive Emotional Effects (large effect) and Positive Holistic Effects (medium effect), with no difference in Negative Side Effects. These results support the hypothesis that medical cannabis alters the pain experience holistically rather than targeting pain intensity alone.
British Journal of Anaesthesia
August 1, 2023
Katja Valli, Linda Radek, Roosa E Kallionpää et al.
Anaesthetic-induced unresponsiveness and non-rapid eye movement (NREM) sleep share similar conscious experiences. In a within-subject study, 39 healthy males received either dexmedetomidine or propofol to induce unresponsiveness, and 37 were later awakened from NREM sleep. Most participants were rousable, with no difference between the two drugs. Lower drug concentrations were linked to being rousable but not to recall of experiences. Of interviews after anaesthesia and sleep, 69.7% and 64.4% included experiences, respectively, with no significant difference in recall. Disconnected dream-like experiences and memory incorporation of the research setting occurred equally often in both states, while awareness was rare. The findings suggest that both states involve disconnected conscious experiences with similar recall frequencies and content.
The Journal of neuroscience : the official journal of the Society for Neuroscience
June 28, 2023
Oskari Kantonen, Lauri Laaksonen, Michael Alkire et al.
Anesthesia-induced disconnectedness—unresponsiveness and unawareness of external events—is linked to reduced activity in the thalamus, but not to widespread cortical suppression, which instead reflects drug exposure itself. In a study of 160 healthy men, four anesthetics (propofol, dexmedetomidine, sevoflurane, S-ketamine) or saline placebo were administered at doses designed to make half of subjects unresponsive. Positron emission tomography showed that, for all anesthetics except S-ketamine, lower thalamic metabolic activity distinguished disconnected from connected states. Widespread cortical metabolic suppression occurred in both connected and disconnected subjects compared with placebo, indicating it is necessary but insufficient for loss of consciousness.