Poultry are electrically stunned before slaughter to induce unconsciousness and to immobilize the chickens for easier killing. From a welfare point of view, electrical stunning should induce immediate and lasting unconsciousness in the chicken. As an alternative to electroencephalography, which measures brain electrical activity, this study used brain impedance recordings, which measure brain m...

BACKGROUND Dynamic action of anesthetic agents was compared at cortical and subcortical levels during induction of anesthesia. Unconsciousness involved the cortical brain but suppression of movement in response to noxious stimuli was mediated through subcortical structures. METHODS Twenty-five patients with Parkinson disease, previously implanted with a deep-brain stimulation electrode, were ...

OBJECTIVES We examine the time course of performance recovery from gravity-induced loss of consciousness (GLOC) and evaluate the utility of exposing participants to repeated bouts of GLOC in promoting recovery time. BACKGROUND A substantial number of accidents among fighter pilots have resulted from episodes of GLOC. U.S. Air Force doctrine holds that when pilots experience GLOC, impairment l...

A widely used general anesthetic directly depolarizes sleep-promoting cells in the brain at doses that produce unconsciousness. The activation of an endogenous sleep pathway likely plays a role in general anesthesia.

This paper provides a detailed review of the clinical aspect and engineering view of how to measure, interpret, model, and control general anesthesia. The mechanisms of anesthesia in terms of unconsciousness, amnesia, analgesia, and akinesia in modern balanced anesthesia are reviewed. The assessment and interpretation of anesthesia according to clinical signs (i.e., lacrimation, sweating, papil...

BACKGROUND It is an open question whether cognitive processes of auditory perception that are mediated by functionally different cortices exhibit the same sensitivity to sedation. The auditory event-related potentials P1, mismatch negativity (MMN), and early right anterior negativity (ERAN) originate from different cortical areas and reflect different stages of auditory processing. The P1 origi...

In this functional magnetic resonance imaging study, we examined the effect of mild propofol sedation and propofol-induced unconsciousness on resting state brain connectivity, using graph analysis based on independent component analysis and a classical seed-based analysis. Contrary to previous propofol research, which mainly emphasized the importance of connectivity in the default mode network ...

BACKGROUND Mechanisms of anesthesia-induced loss of consciousness remain poorly understood. Resting-state functional magnetic resonance imaging allows investigating whole-brain connectivity changes during pharmacological modulation of the level of consciousness. METHODS Low-frequency spontaneous blood oxygen level-dependent fluctuations were measured in 19 healthy volunteers during wakefulnes...

BACKGROUND Significant advances have been made in our understanding of subcortical processes related to anesthetic- and sleep-induced unconsciousness, but the associated changes in cortical connectivity and cortical neurochemistry have yet to be fully clarified. METHODS Male Sprague-Dawley rats were instrumented for simultaneous measurement of cortical acetylcholine and electroencephalographi...