Neuroreport
October 4, 2023
William D. S. Killgore, Samantha Jankowski, Kymberly Henderson-Arredondo et al.
19 citations
Insomnia is often accompanied by excessive pre-sleep rumination. Such ruminative thinking is also associated with increased connectivity of the default mode network (DMN). It is likely that DMN connectivity and associated rumination contribute to the pathogenesis of insomnia. We hypothesized that resting state functional connectivity (rsFC) between the DMN and other brain regions prior to...
Neuroreport
February 6, 2019
Pil-Jong Kim, H. Kim, T. Shin
Integration of neural information could be considered a crucial element in maintaining consciousness. Although consciousness is usually maintained during sedation, strictly speaking, the sedative state is different from consciousness. Nitrous oxide (N2O) has been used widely to sedate patients for dental procedures. However, its mechanism remains unclear. The aim of this study was to analyze...
Neuroreport
December 5, 2018
Diego B G Rodrigues, Shirley S Lacerda, Joana B Balardin et al.
Among several cognitive advantages, meditation is thought to enhance practitioners' capacity for sustained attention. In the present study, we explored this question by testing meditation practitioners (meditators) and nonpractitioners (nonmeditators) on a task that requires sustained attention, the Stroop Word-Color Task (SWCT), while using functional MRI. Participants were all right-handed...
Neuroreport
August 24, 2011
Shaowei Xue, Yi-Yuan Tang, Michael I Posner
Previous studies have found that short-term integrative body-mind training (IBMT) has positive effects on the brain structure and function in the anterior cingulate cortex. Here, we determined whether 11 h of IBMT alters topological properties of the anterior cingulate cortex in brain functional networks. We applied network analysis to resting-state functional connectivity between 90 cortical...
Neuroreport
January 28, 2009
Peter Vestergaard‐Poulsen, Martijn van Beek, Joshua Skewes et al.
Extensive practice involving sustained attention can lead to changes in brain structure. Here, we report evidence of structural differences in the lower brainstem of participants engaged in the long-term practice of meditation. Using magnetic resonance imaging, we observed higher gray matter density in lower brain stem regions of experienced meditators compared with age-matched nonmeditators....
Neuroreport
May 28, 2008
Robyn L. Bluhm, Elizabeth A. Osuch, Ruth A. Lanius et al.
229 citations
The 'default mode network' is a set of brain regions showing correlated, low-frequency activity during rest. It includes the posterior cingulate/precuneus, medial prefrontal cortex, and bilateral inferior parietal cortex. Earlier studies have characterized this network using either region of interest-based correlation analyses or data-driven techniques; however, there is some disagreement over...
Neuroreport
October 29, 2007
Narayanan Srinivasan, Shruti Baijal
The mismatch negativity (MMN) paradigm that is an indicator of preattentive processing was used to study the effects of concentrative meditation. Sudarshan Kriya Yoga meditation is a yogic exercise practiced in an ordered sequence beginning with breathing exercises, and ending with concentrative (Sahaj Samadhi) meditation. Auditory MMN waveforms were recorded at the beginning and after each of...
Neuroreport
May 7, 2007
Thorsten Barnhofer, Danielle Duggan, Catherine Crane et al.
This study investigated the effects of a meditation-based treatment for preventing relapse to depression, mindfulness-based cognitive therapy (MBCT), on prefrontal alpha-asymmetry in resting electroencephalogram (EEG), a biological indicator of affective style. Twenty-two individuals with a previous history of suicidal depression were randomly assigned to either MBCT (N=10) or...
Neuroreport
August 21, 2006
David W. Orme-Johnson, Robert H Schneider, Young D Son et al.
Some meditation techniques reduce pain, but there have been no studies on how meditation affects the brain's response to pain. Functional magnetic resonance imaging of the response to thermally induced pain applied outside the meditation period found that long-term practitioners of the Transcendental Meditation technique showed 40-50% fewer voxels responding to pain in the thalamus and total...
Neuroreport
November 7, 2005
Sara W. Lazar, Catherine E. Kerr, Rachel H. Wasserman et al.
1,707 citations
Previous research indicates that long-term meditation practice is associated with altered resting electroencephalogram patterns, suggestive of long lasting changes in brain activity. We hypothesized that meditation practice might also be associated with changes in the brain's physical structure. Magnetic resonance imaging was used to assess cortical thickness in 20 participants with extensive...
Neuroreport
August 1, 2004
Olivia Carter, John D. Pettigrew, David C. Burr et al.
83 citations
The hallucinogenic serotonin(1A&2A) agonist psilocybin is known for its ability to induce illusions of motion in otherwise stationary objects or textured surfaces. This study investigated the effect of psilocybin on local and global motion processing in nine human volunteers. Using a forced choice direction of motion discrimination task we show that psilocybin selectively impairs coherence...
Neuroreport
October 1, 2003
Jörg Daumann, Ralph Schnitker, Jürgen Weidemann et al.
46 citations
Poor cognitive performance in ecstasy (3,4-methylenedioxymethamphetamine; MDMA) users has been related to the well-recognized neurotoxic effects of the drug upon central serotonergic and possibly also dopaminergic systems. However, concomitant use of other drugs has been a critical confound in most investigations. In this study we used an n-back task and fMRI to investigate working memory...
Neuroreport
June 11, 2003
Daniel S O'Leary, Robert I Block, Beth M Turner et al.
The effects of marijuana on brain perfusion and internal timing were assessed using [15O] water PET in occasional and chronic users. Twelve volunteers who smoked marijuana recreationally about once weekly, and 12 volunteers who smoked daily for a number of years performed a self-paced counting task during PET imaging, before and after smoking marijuana and placebo cigarettes. Smoking marijuana...
Neuroreport
November 16, 2001
R Brett, F MacKenzie, J Pratt
The effects of Delta9-tetrahydrocannabinol (THC) on neural activity in the rat were investigated using [14C]2-deoxyglucose autoradiography to measure local cerebral glucose use. Overall, THC reduced glucose use at 5 mg/kg and slightly increased it at 1 mg/kg. Significant reductions were seen at the higher dose in regions of the hippocampus and limbic system, and in structures associated with...
Neuroreport
February 12, 2001
M B Leal, T Emanuelli, L D Porciúncula et al.
14 citations
Ibogaine has aroused expectations as a potentially innovative medication for drug addiction. It has been proposed that antagonism of the NMDA receptor by ibogaine may be one of the mechanisms underlying its antiaddictive properties; glutamate has also been implicated in ibogaine-induced neurotoxicity. We here report the effects of ibogaine on [3H]glutamate release and uptake in cortical and...
Neuroreport
May 1, 2000
Sara W. Lazar, George Bush, Randy L. Gollub et al.
443 citations
Meditation is a conscious mental process that induces a set of integrated physiologic changes termed the relaxation response. Functional magnetic resonance imaging (fMRI) was used to identify and characterize the brain regions that are active during a simple form of meditation. Significant (p <10−7) signal increases were observed in the group-averaged data in the dorsolateral prefrontal and...
Neuroreport
2000
Alex Gamma, Edi Frei, Dietrich Lehmann et al.
81 citations
Resting EEG during open and closed eyes and subsequent mood ratings were obtained from 15 Ecstasy users and 14 Ecstasy-naive controls. Absolute spectral power on the scalp, and the three-dimensional, intracerebral distribution of neuroelectric activity using low resolution brain electromagnetic tomography (LORETA) were computed. LORETA revealed global increases of theta, alpha 1 and beta 2/3...
Neuroreport
November 1, 1999
Norberto Aguirre, Meritxell Barrionuevo, Marı́a J. Ramı́rez et al.
89 citations
A single administration of 3,4-methylenedioxymetham-phetamine (MDMA, 20 mg/kg, i.p.), induced significant hyperthermia in rats and reduced 5-hydroxytryptamine (5-HT) content and [3H]paroxetine-labeled 5-HT transporter density in the frontal cortex, striatum and hippocampus by 40–60% 1 week later. MDMA treatment also increased glial fibrillary acidic protein (GFAP) immunoreactivity in the...
Neuroreport
December 1, 1998
Franz X. Vollenweider, M. F. I. Vollenweider-Scherpenhuyzen, Andreas Bäbler et al.
1,023 citations
Psilocybin, an indoleamine hallucinogen, produces a psychosis-like syndrome in humans that resembles first episodes of schizophrenia. In healthy human volunteers, the psychotomimetic effects of psilocybin were blocked dose-dependently by the serotonin-2A antagonist ketanserin or the atypical antipsychotic risperidone, but were increased by the dopamine antagonist and typical antipsychotic...
Neuroreport
May 11, 1998
B Rho, Stanley D Glick
35 citations
Ibogaine, an alkaloid found in the root bark of the African shrub Tabernanthe iboga, has been claimed to interrupt opioid dependence in humans; in animals, it has been shown to inhibit morphine self-administration and to attenuate signs of morphine withdrawal. However, ibogaine has some neurotoxicity, and because of this, efficacious and safer congeners of ibogaine have been sought,...
Neuroreport
January 5, 1998
John Pablo, Deborah C. Mash
27 citations
Noribogaine is formed in vivo by the O-demethylation of the indole alkaloid ibogaine. We report here that noribogaine acts as a full agonist at the mu-opioid receptor. Noribogaine-stimulated guanylyl 5'gamma-[35S]thio]triphosphate ([35S]GTPgammaS) was studied in rat thalamic membranes to measure activation of guanine nucleotide binding proteins (G-proteins) in the presence of excess GDP....
Neuroreport
August 21, 1995
E O'Hearn, P Zhang, M E Molliver
77 citations
Ibogaine causes degeneration of Purkinje cells (PKCs), presumably via activation of neurons in the inferior olive leading to release of glutamate at climbing fiber terminals. Following ibogaine administration, some Purkinje cells express NADPH-diaphorase and neuronal NOS (nNOS), neither of which is present normally in these cells. The induction of NOS is delayed in onset, dose-related, and...
Neuroreport
April 1, 1995
Adrienne C. Lahti, Henry H. Holcomb, Deborah R. Medoff et al.
440 citations
The non-competitive NMDA antagonist ketamine, given to schizophrenic individuals in subanesthetic doses, produced a short-lived, discrete activation of their psychotic symptoms, which had striking similarities to symptoms of their usual psychotic episodes. To further study this psychotomimetic property of ketamine, we administered 0.3 mg kg-1 of the drug to schizophrenic individuals during a...
Neuroreport
March 7, 1995
K Fukui, Y Kawashima, H Iizumi et al.
Phencyclidine (PCP) is a dissociative drug and has been known to be an antagonist of N-methyl-D-aspartate (NMDA) receptor. We examined possible effects of acute treatment with PCP on neuropeptide Y (NPY) immunoreactive nerve fibres and cell bodies in rat forebrain by immunocytochemistry combined with morphometric analysis. Following the treatment, significant alterations were observed...
Neuroreport
October 25, 1993
G Ellison, R C Switzer
Patterns of neural degeneration were compared following continuous administration of four drugs of addiction, each of which induces model psychoses in chronic addicts. D-amphetamine (D-Amph), cocaine (Coc), or phencyclidine (PCP) were administered continuously over a 5-day period. Both D-Amph and Coc induced pronounced degeneration in fasciculus retroflexus, but only D-Amph further induced...