scholarly journals Cannabis affects people differently: inter-subject variation in the psychotogenic effects of Δ9-tetrahydrocannabinol: a functional magnetic resonance imaging study with healthy volunteers

2012 ◽  
Vol 43 (6) ◽  
pp. 1255-1267 ◽  
Author(s):  
Z. Atakan ◽  
S. Bhattacharyya ◽  
P. Allen ◽  
R. Martín-Santos ◽  
J. A. Crippa ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Healthy Volunteers ◽  
Temporal Cortex ◽  
Psychotic Symptoms ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Middle Temporal ◽  
The Right

BackgroundCannabis can induce transient psychotic symptoms, but not all users experience these adverse effects. We compared the neural response to Δ9-tetrahydrocannabinol (THC) in healthy volunteers in whom the drug did or did not induce acute psychotic symptoms.MethodIn a double-blind, placebo-controlled, pseudorandomized design, 21 healthy men with minimal experience of cannabis were given either 10 mg THC or placebo, orally. Behavioural and functional magnetic resonance imaging measures were then recorded whilst they performed a go/no-go task.ResultsThe sample was subdivided on the basis of the Positive and Negative Syndrome Scale positive score following administration of THC into transiently psychotic (TP; n = 11) and non-psychotic (NP; n = 10) groups. During the THC condition, TP subjects made more frequent inhibition errors than the NP group and showed differential activation relative to the NP group in the left parahippocampal gyrus, the left and right middle temporal gyri and in the right cerebellum. In these regions, THC had opposite effects on activation relative to placebo in the two groups. The TP group also showed less activation than the NP group in the right middle temporal gyrus and cerebellum, independent of the effects of THC.ConclusionsIn this first demonstration of inter-subject variability in sensitivity to the psychotogenic effects of THC, we found that the presence of acute psychotic symptoms was associated with a differential effect of THC on activation in the ventral and medial temporal cortex and cerebellum, suggesting that these regions mediate the effects of the drug on psychotic symptoms.

scholarly journals Resting-State Functional Magnetic Resonance Imaging and Functional Connectivity Density Mapping in Patients With Optic Neuritis

2021 ◽  
Vol 15 ◽  
Author(s):  
Ke Song ◽  
Yong Wang ◽  
Mei-Xia Ren ◽  
Jiao Li ◽  
Ting Su ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Functional Magnetic Resonance Imaging ◽  
Optic Neuritis ◽  
Resting State ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Functional Connectivity Density ◽  
The Right

Background: Using resting-state functional connectivity (rsFC), we investigated alternations in spontaneous brain activities reflected by functional connectivity density (FCD) in patients with optic neuritis (ON).Methods: We enrolled 28 patients with ON (18 males, 10 females) and 24 healthy controls (HCs; 16 males, 8 females). All subjects underwent functional magnetic resonance imaging (fMRI) in a quiet state to determine the values of rsFC, long-range FCD (longFCD), and short-range FCD (IFCD). Receiver operating characteristic (ROC) curves were generated to distinguish patients from HCs.Results: The ON group exhibited obviously lower longFCD values in the left inferior frontal gyrus triangle, the right precuneus and the right anterior cingulate, and paracingulate gyri/median cingulate and paracingulate gyri. The left median cingulate and paracingulate gyri and supplementary motor area (SMA) were also significantly lower. Obviously reduced IFCD values were observed in the left middle temporal gyrus/angular gyrus/SMA and right cuneus/SMA compared with HCs.Conclusion: Abnormal neural activities were found in specific brain regions in patients with ON. Specifically, they showed significant changes in rsFC, longFCD, and IFCD values. These may be useful to identify the specific mechanism of change in brain function in ON.

scholarly journals Facial fear processing and psychotic symptoms in schizophrenia: functional magnetic resonance imaging study

2008 ◽  
Vol 192 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Panayiota G. Michalopoulou ◽  
Simon Surguladze ◽  
Lucy A. Morley ◽  
Vincent P. Giampietro ◽  
Robin M. Murray ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Visual Processing ◽  
Negative Symptoms ◽  
Imaging Study ◽  
Superior Temporal Gyrus ◽  
Psychotic Symptoms ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging

BackgroundThe recognition of negative facial affect is impaired in people with schizophrenia. The neural underpinnings of this deficit and its relationship to the symptoms of psychosis are still unclear.AimsTo examine the association between positive and negative psychotic symptoms and activation within the amygdala and extrastriate visual regions of patients with schizophrenia during fearful and neutral facial expression processing.MethodFunctional magnetic resonance imaging was used to measure neural responses to neutral and fearful facial expressions in 11 patients with schizophrenia and 9 healthy volunteers during an implicit emotional task.ResultsNo association between amygdala activation and positive symptoms was found; the activation within the left superior temporal gyrus was negatively associated with the negative symptoms of the patients.ConclusionsOur results indicate an association between impaired extrastriate visual processing of facial fear and negative symptoms, which may underlie the previously reported difficulties of patients with negative symptoms in the recognition of facial fear.

scholarly journals Processing facial emotions in adults with velo-cardio-facial syndrome: functional magnetic resonance imaging

2006 ◽  
Vol 189 (6) ◽  
pp. 560-561 ◽  
Author(s):  
Therese Van Amelsvoort ◽  
Nicole Schmitz ◽  
Eileen Daly ◽  
Quinton Deeley ◽  
Hugo Critchley ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Emotional Processing ◽  
Brain Regions ◽  
Functional Neuroanatomy ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
The Right ◽  
Velo Cardio Facial Syndrome

SummaryWe studied the functional neuroanatomy of social behaviour in velo-cardio-facial syndrome (VCFS) using a facial emotional processing task and functional magnetic resonance imaging in adults with this syndrome and controls matched for age and IQ. The VCFS group had less activation in the right insula and frontal brain regions and more activation in occipital regions. Genetically determined abnormalities in pathways including those involved in emotional processing may underlie deficits in social cognition in people with VCFS.

scholarly journals Decreased frontal activation in schizophrenics during stimulation with the Continuous Performance Test - a functional magnetic resonance imaging study

1999 ◽  
Vol 14 (1) ◽  
pp. 17-24 ◽  
Author(s):  
H.-P. Volz ◽  
C. Gaser ◽  
F. Häger ◽  
R. Rzanny ◽  
J. Pönisch ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Performance Test ◽  
Continuous Performance Test ◽  
Continuous Performance ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Vast Number ◽  
The Right

SummaryThe Continuous Performance Test (CPT) has become an essential constituent of the neuropsychological investigation of schizophrenia. Also, a vast number of brain imaging studies, mostly PET investigations, have employed the CPT as a cognitive challenge and established a relative hypofrontality in schizophrenics compared to controls. The aim of the present investigation was to clarify whether this predescribed hypofrontality could also be verified using functional magnetic resonance imaging (fMRI). 20 healthy volunteers and 14 schizophrenics on stable neuroleptic medication were included. Imaging was performed using the CPT-double-T-version and a clinical 1.5 T MRI-scanner with a single slice technique and a T2*-weighted gradient-echo-sequence. The schizophrenics exhibited a decreased activation in the right mesial prefrontal cortex, the right cingulate and the left thalamus compared to controls. These results obtained by fMRI are discussed in relation to published findings using PET.

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