Proceedings of the National Academy of Sciences of the United States of America
August 31, 2010
Yi-Yuan Tang, Qilin Lu, Xiujuan Geng et al.
The anterior cingulate cortex (ACC) is part of a network implicated in the development of self-regulation and whose connectivity changes dramatically in development. In previous studies we showed that 3 h of mental training, based on traditional Chinese medicine (integrative body-mind training, IBMT), increases ACC activity and improves self-regulation. However, it is not known whether changes...
Proceedings of the National Academy of Sciences of the United States of America
February 23, 2010
Michel Magnin, Marc Rey, Hélène Bastuji et al.
Thalamic and cortical activities are assumed to be time-locked throughout all vigilance states. Using simultaneous intracortical and intrathalamic recordings, we demonstrate here that the thalamic deactivation occurring at sleep onset most often precedes that of the cortex by several minutes, whereas reactivation of both structures during awakening is synchronized. Delays between thalamus and...
Proceedings of the National Academy of Sciences of the United States of America
July 7, 2009
Robert G Shulman, Fahmeed Hyder, Douglas L Rothman
An individual, human or animal, is defined to be in a conscious state empirically by the behavioral ability to respond meaningfully to stimuli, whereas the loss of consciousness is defined by unresponsiveness. PET measurements of glucose or oxygen consumption show a widespread approximately 45% reduction in cerebral energy consumption with anesthesia-induced loss of consciousness. Because...
Proceedings of the National Academy of Sciences of the United States of America
June 2, 2009
Yi-Yuan Tang, Yinghua Ma, Yaxin Fan et al.
Five days of integrative body-mind training (IBMT) improves attention and self-regulation in comparison with the same amount of relaxation training. This paper explores the underlying mechanisms of this finding. We measured the physiological and brain changes at rest before, during, and after 5 days of IBMT and relaxation training. During and after training, the IBMT group showed significantly...
Proceedings of the National Academy of Sciences of the United States of America
May 26, 2009
Kalina Christoff, Alan M Gordon, Jonathan Smallwood et al.
1,832 citations
Although mind wandering occupies a large proportion of our waking life, its neural basis and relation to ongoing behavior remain controversial. We report an fMRI study that used experience sampling to provide an online measure of mind wandering during a concurrent task. Analyses focused on the interval of time immediately preceding experience sampling probes demonstrate activation of default...
Proceedings of the National Academy of Sciences of the United States of America
February 3, 2009
Tristan A Bekinschtein, Stanislas Dehaene, Benjamin Rohaut et al.
Can conscious processing be inferred from neurophysiological measurements? Some models stipulate that the active maintenance of perceptual representations across time requires consciousness. Capitalizing on this assumption, we designed an auditory paradigm that evaluates cerebral responses to violations of temporal regularities that are either local in time or global across several seconds....
Proceedings of the National Academy of Sciences of the United States of America
June 10, 2008
Sebastien Carnicella, Viktor Kharazia, Jérôme Jeanblanc et al.
132 citations
Previously, we demonstrated that the action of the natural alkaloid, ibogaine, to reduce alcohol (ethanol) consumption is mediated by the glial cell line-derived neurotrophic factor (GDNF) in the ventral tegmental area (VTA). Here we set out to test the actions of GDNF in the VTA on ethanol-drinking behaviors. We found that GDNF infusion very rapidly and dose-dependently reduced rat ethanol,...
Proceedings of the National Academy of Sciences of the United States of America
October 9, 2007
Alexandra Jean, Grégory Conductier, Christine Manrique et al.
Anorexia nervosa is a growing concern in mental health, often inducing death. The potential neuronal deficits that may underlie abnormal inhibitions of food intake, however, remain largely unexplored. We hypothesized that anorexia may involve altered signaling events within the nucleus accumbens (NAc), a brain structure involved in reward. We show here that direct stimulation of serotonin...
Proceedings of the National Academy of Sciences of the United States of America
June 5, 2007
H Henrik Ehrsson, Katja Wiech, Nikolaus Weiskopf et al.
The feeling of body ownership is a fundamental aspect of self-consciousness. The underlying neural mechanisms can be studied by using the illusion where a person is made to feel that a rubber hand is his or her own hand by brushing the person's hidden real hand and synchronously brushing the artificial hand that is in full view. Here we show that threat to the rubber hand can induce a similar...
Proceedings of the National Academy of Sciences of the United States of America
June 5, 2007
Jean-Claude Béïque, Mays Imad, Ljiljana Mladenovic et al.
Classic hallucinogens such as lysergic acid diethylamide are thought to elicit their psychotropic actions via serotonin receptors of the 5-hydroxytryptamine 2A subtype (5-HT(2A)R). One likely site for these effects is the prefrontal cortex (PFC). Previous studies have shown that activation of 5-HT(2A)Rs in this region results in a robust increase in spontaneous glutamatergic synaptic activity,...
Proceedings of the National Academy of Sciences of the United States of America
December 9, 2003
Gary F. Egan, Tim Silk, Frank Zamarripa et al.
Thirst was induced by rapid i.v. infusion of hypertonic saline (0.51 M at 13.4 ml/min). Ten humans were neuroimaged by positron-emission tomography (PET) and four by functional MRI (fMRI). PET images were made 25 min after beginning infusion, when the sensation of thirst began to enter the stream of consciousness. The fMRI images were made when the maximum rate of increase of thirst occurred....
Proceedings of the National Academy of Sciences of the United States of America
July 8, 2003
Stanislas Dehaene, Claire Sergent, Jean-Pierre Changeux
The subjective experience of perceiving visual stimuli is accompanied by objective neuronal activity patterns such as sustained activity in primary visual area (V1), amplification of perceptual processing, correlation across distant regions, joint parietal, frontal, and cingulate activation, gamma-band oscillations, and P300 waveform. We describe a neuronal network model that aims at explaining...
Proceedings of the National Academy of Sciences of the United States of America
December 27, 2002
Michael D. Greicius, B. Krasnow, A. Reiss et al.
Functional imaging studies have shown that certain brain regions, including posterior cingulate cortex (PCC) and ventral anterior cingulate cortex (vACC), consistently show greater activity during resting states than during cognitive tasks. This finding led to the hypothesis that these regions constitute a network supporting a default mode of brain function. In this study, we investigate three...
Proceedings of the National Academy of Sciences of the United States of America
September 3, 2002
Bryan L. Roth, Karen Baner, Richard B Westkaemper et al.
782 citations
Salvia divinorum, whose main active ingredient is the neoclerodane diterpene Salvinorin A, is a hallucinogenic plant in the mint family that has been used in traditional spiritual practices for its psychoactive properties by the Mazatecs of Oaxaca, Mexico. More recently, S. divinorum extracts and Salvinorin A have become more widely used in the U.S. as legal hallucinogens. We discovered that...
Proceedings of the National Academy of Sciences of the United States of America
August 18, 1998
M Diana, M Melis, A L Muntoni et al.
The mesolimbic dopamine system has recently been implicated in the long-term aversive consequences of withdrawal from major drugs of abuse. In the present study we sought to determine whether mesolimbic dopamine neurons are involved in the neurobiologic mechanisms underlying withdrawal from chronic cannabinoid exposure. Rats were treated chronically with the major psychoactive ingredient of...
Proceedings of the National Academy of Sciences of the United States of America
August 15, 1995
A V Ferrer-Montiel, W Sun, M Montal
The N-methyl-D-aspartate receptor (NMDAR), a pivotal entity for synaptic plasticity and excitotoxicity in the brain, is a target of psychotomimetic drugs such as phencyclidine (PCP) and dizolcipine (MK-801). In contrast, a related glutamate receptor, the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate/kainate receptor GluR1, is weakly sensitive to these drugs. Three point mutations on...
Proceedings of the National Academy of Sciences of the United States of America
August 2, 1994
M I Posner
A number of recent papers and books discuss theoretical efforts toward a scientific understanding of consciousness. Progress in imaging networks of brain areas active when people perform simple tasks may provide a useful empirical background for distinguishing conscious and unconscious information processing. Attentional networks include those involved in orienting to sensory stimuli,...
Proceedings of the National Academy of Sciences of the United States of America
December 1, 1992
D L Schacter
Recent evidence from cognitive science and neuroscience indicates that brain-damaged patients and normal subjects can exhibit nonconscious or implicit knowledge of stimuli that they fail to recollect consciously or perceive explicitly. Dissociations between implicit and explicit knowledge, which have been observed across a variety of domains, tasks, and materials, raise fundamental questions...
Proceedings of the National Academy of Sciences of the United States of America
March 1990
M Herkenham, A B Lynn, M D Little et al.
[3H]CP 55,940, a radiolabeled synthetic cannabinoid, which is 10-100 times more potent in vivo than delta 9-tetrahydrocannabinol, was used to characterize and localize a specific cannabinoid receptor in brain sections. The potencies of a series of natural and synthetic cannabinoids as competitors of [3H]CP 55,940 binding correlated closely with their relative potencies in several biological...
Proceedings of the National Academy of Sciences of the United States of America
1974
Edward W. Voss, Jeffrey L. Winkelhake
8 citations
Lymphoid cells from hyperimmune rabbits producing antibodies to a hapten, incubated in the presence of d-lysergic acid diethylamide, continued to synthesize protein at a normal rate. Isoelectric focusing analysis of the low-molecular-weight protein secreted by the cells incubated with lysergic acid diethylamide indicated two components, with pI's of 4.9 and 5.2. Immune cells not exposed to...