scholarly journals Anomalies of asymmetry of pyramidal cell density and structure in dorsolateral prefrontal cortex in schizophrenia

2006 ◽  
Vol 188 (1) ◽  
pp. 26-31 ◽  
Author(s):  
Thomas J. Cullen ◽  
Mary A. Walker ◽  
Sharon L. Eastwood ◽  
Margaret M. Esiri ◽  
Paul J. Harrison ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Right Hemisphere ◽  
Cellular Level ◽  
Cortical Layer ◽  
Association Cortex ◽  
Neuronal Density ◽  
Size And Shape ◽  
Dorsolateral Prefrontal ◽  
The Right

BackgroundStudies suggest that neuronal density in left dorsolateral prefrontal cortex is increased in schizophrenia.AimsTo replicate these findings and extend them to both hemispheres.MethodNeuronal density, size and shape were estimated in the prefrontal cortex (Brodmann area 9) of the left and right hemispheres of brains taken postmortem from 10 people with schizophrenia and 10 without mental illness (6 men, 4 women in both groups).ResultsOverall neuronal density (individually corrected for shrinkage) did not differ between the groups. In the control brains, density was generally greater in the left than the right hemisphere, the reverse was seen in the schizophrenia brains; this loss or reversal of asymmetry was most significant in cortical layer 3. Pyramidal neurons in this cell layer were significantly larger on the left and more spherical in shape than on the right side in control brains, but size and shape did not differ between the two sides in schizophrenia. Non-pyramidal and glial cell densities were unchanged.ConclusionsWe failed to find an increase in neuronal density, but found evidence at a cellular level of loss or reversal of asymmetry, consistent with the hypothesis of a primary change in the relative development of areas of heteromodal association cortex in the two hemispheres.

scholarly journals Functional connectivity of dorsolateral prefrontal cortex predicts cocaine relapse

2020 ◽  
Author(s):  
Tianye Zhai ◽  
Betty Jo Salmeron ◽  
Hong Gu ◽  
Bryon Adinoff ◽  
Elliot A. Stein ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Functional Connectivity ◽  
Dorsolateral Prefrontal Cortex ◽  
Addiction Treatment ◽  
Right Hemisphere ◽  
Cox Regression ◽  
Brain Regions ◽  
Psychosocial Treatment ◽  
Dorsolateral Prefrontal ◽  
The Right

AbstractBackgroundRelapse is one of the most perplexing problems of addiction. The dorsolateral prefrontal cortex (DLPFC) is crucially involved in numerous cognitive and affective processes that are implicated in phenotypes of addiction, and is one of the most frequently reported brain regions with aberrant functionality in substance use disorders. However, the DLPFC is an anatomically large and functionally heterogeneous region, and the specific DLPFC-based circuits that contribute to drug relapse remain unknown.MethodsWe systematically investigated the relationship of cocaine relapse with 98 DLPFC functional circuits defined by evenly sampling the entire bilateral DLPFC in a cohort of cocaine dependent patients (n=43, 5F) following a psychosocial treatment intervention. A Cox regression model was utilized to predict relapse likelihood based on DLPFC functional connectivity strength.ResultsFunctional connectivity from 3 of the 98 DLPFC loci, one on the left and two on the right hemisphere, significantly predicted cocaine relapse with an accuracy of 83.9%, 84.7% and 85.4%, respectively. Combining all three significantly improved prediction validity to 87.5%. Protective and risk circuits related to these DLPFC loci were identified that are known to support “bottom up” drive to use drug and “top down” control over behavior together with social emotional, learning and memory processing.ConclusionThree DLPFC-centric circuits were identified that predict relapse to cocaine use with high accuracy. These functionally distinct DLPFC-based circuits provide insights into the multiple roles played by the DLPFC in cognitive and affective functioning that affects treatment outcome. The identified DLPFC loci may serve as potential neuromodulation targets for addiction treatment and as clinically relevant biomarkers of its efficacy.

scholarly journals Null Effect of Transcranial Static Magnetic Field Stimulation over the Dorsolateral Prefrontal Cortex on Behavioral Performance in a Go/NoGo Task

2021 ◽  
Vol 11 (4) ◽  
pp. 483
Author(s):  
Tatsunori Watanabe ◽  
Nami Kubo ◽  
Xiaoxiao Chen ◽  
Keisuke Yunoki ◽  
Takuya Matsumoto ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Prefrontal Cortex ◽  
Inhibitory Control ◽  
Static Magnetic Field ◽  
Dorsolateral Prefrontal Cortex ◽  
Cortical Excitability ◽  
Control Function ◽  
Field Stimulation ◽  
Dorsolateral Prefrontal ◽  
The Right

The purpose of this pilot study was to investigate whether transcranial static magnetic field stimulation (tSMS), which can modulate cortical excitability, would influence inhibitory control function when applied over the dorsolateral prefrontal cortex (DLPFC). Young healthy adults (n = 8, mean age ± SD = 24.4 ± 4.1, six females) received the following stimulations for 30 min on different days: (1) tSMS over the left DLPFC, (2) tSMS over the right DLPFC, and (3) sham stimulation over either the left or right DLPFC. The participants performed a Go/NoGo task before, immediately after, and 10 min after the stimulation. They were instructed to extend the right wrist in response to target stimuli. We recorded the electromyogram from the right wrist extensor muscles and analyzed erroneous responses (false alarm and missed target detection) and reaction times. As a result, 50% of the participants made erroneous responses, and there were five erroneous responses in total (0.003%). A series of statistical analyses revealed that tSMS did not affect the reaction time. These preliminary findings suggest the possibility that tSMS over the DLPFC is incapable of modulating inhibitory control and/or that the cognitive load imposed in this study was insufficient to detect the effect.

scholarly journals Single-Pulse Transcranial Magnetic Stimulation-Evoked Potential Amplitudes and Latencies in the Motor and Dorsolateral Prefrontal Cortex among Young, Older Healthy Participants, and Schizophrenia Patients

2021 ◽  
Vol 11 (1) ◽  
pp. 54
Author(s):  
Yoshihiro Noda ◽  
Mera S. Barr ◽  
Reza Zomorrodi ◽  
Robin F. H. Cash ◽  
Pantelis Lioumis ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Evoked Potential ◽  
Single Pulse ◽  
Signal Propagation ◽  
Lower Amplitude ◽  
Dorsolateral Prefrontal ◽  
The Right

Background: The combination of transcranial magnetic stimulation (TMS) with electroencephalography (EEG) allows for non-invasive investigation of cortical response and connectivity in human cortex. This study aimed to examine the amplitudes and latencies of each TMS-evoked potential (TEP) component induced by single-pulse TMS (spTMS) to the left motor (M1) and dorsolateral prefrontal cortex (DLPFC) among healthy young participants (YNG), older participants (OLD), and patients with schizophrenia (SCZ). Methods: We compared the spatiotemporal characteristics of TEPs induced by spTMS among the groups. Results: Compared to YNG, M1-spTMS induced lower amplitudes of N45 and P180 in OLD and a lower amplitude of P180 in SCZ, whereas the DLPFC-spTMS induced a lower N45 in OLD. Further, OLD demonstrated latency delays in P60 after M1-spTMS and in N45-P60 over the right central region after left DLPFC-spTMS, whereas SCZ demonstrated latency delays in N45-P60 over the midline and right central regions after DLPFC-spTMS. Conclusions: These findings suggest that inhibitory and excitatory mechanisms mediating TEPs may be altered in OLD and SCZ. The amplitude and latency changes of TEPs with spTMS may reflect underlying neurophysiological changes in OLD and SCZ, respectively. The spTMS administered to M1 and the DLPFC can probe cortical functions by examining TEPs. Thus, TMS-EEG can be used to study changes in cortical connectivity and signal propagation from healthy to pathological brains.

scholarly journals Influence of Atomoxetine on Relationship Between ADHD Symptoms and Prefrontal Cortex Activity During Task Execution in Adult Patients

2021 ◽  
Vol 15 ◽  
Author(s):  
Atsunori Sugimoto ◽  
Yutaro Suzuki ◽  
Kiyohiro Yoshinaga ◽  
Naoki Orime ◽  
Taketsugu Hayashi ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Rating Scales ◽  
Clinical Symptoms ◽  
Adult Patients ◽  
Adhd Symptoms ◽  
Analytical Strategy ◽  
Positive Correlation ◽  
Dorsolateral Prefrontal ◽  
The Right

Objective: We conducted this non-randomized prospective interventional study to clarify the relationship between improved attention-deficit hyperactivity disorder (ADHD) symptoms and regional brain activity.Methods: Thirty-one adult patients underwent near-infrared spectroscopy examinations during a go/no-go task, both before and 8 weeks after atomoxetine administration.Results: Clinical symptoms, neuropsychological results of the go/no-go task, and bilateral lateral prefrontal activity significantly changed. A positive correlation was observed between right dorsolateral prefrontal cortex activity and Conners’ Adult ADHD Rating Scales scores. Before atomoxetine administration, no correlations between prefrontal cortex activity and clinical symptoms were observed in all cases. When participants were divided into atomoxetine-responder and non-responder groups, a positive correlation was observed between prefrontal cortex activity and clinical symptoms in the non-responder group before treatment but not in the responder group, suggesting that non-responders can activate the prefrontal cortex without atomoxetine.Conclusions: Individuals with increased ADHD symptoms appear to recruit the right dorsolateral prefrontal cortex more strongly to perform the same task than those with fewer symptoms. In clinical settings, individuals with severe symptoms are often observed to perform more difficultly when performing the tasks which individuals with mild symptoms can perform easily. The atomoxetine-responder group was unable to properly activate the right dorsolateral prefrontal cortex when necessary, and the oral administration of atomoxetine enabled these patients to activate this region. In brain imaging studies of heterogeneous syndromes such as ADHD, the analytical strategy used in this study, involving drug-responsivity grouping, may effectively increase the signal-to-noise ratio.

scholarly journals Reducing future fears by suppressing the brain mechanisms underlying episodic simulation

2016 ◽  
Vol 113 (52) ◽  
pp. E8492-E8501 ◽  
Author(s):  
Roland G. Benoit ◽  
Daniel J. Davies ◽  
Michael C. Anderson
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Ventromedial Prefrontal Cortex ◽  
Episodic Simulation ◽  
Dorsolateral Prefrontal ◽  
Future Events ◽  
The Right ◽  
Development Of Anxiety ◽  
The Brain

Imagining future events conveys adaptive benefits, yet recurrent simulations of feared situations may help to maintain anxiety. In two studies, we tested the hypothesis that people can attenuate future fears by suppressing anticipatory simulations of dreaded events. Participants repeatedly imagined upsetting episodes that they feared might happen to them and suppressed imaginings of other such events. Suppressing imagination engaged the right dorsolateral prefrontal cortex, which modulated activation in the hippocampus and in the ventromedial prefrontal cortex (vmPFC). Consistent with the role of the vmPFC in providing access to details that are typical for an event, stronger inhibition of this region was associated with greater forgetting of such details. Suppression further hindered participants’ ability to later freely envision suppressed episodes. Critically, it also reduced feelings of apprehensiveness about the feared scenario, and individuals who were particularly successful at down-regulating fears were also less trait-anxious. Attenuating apprehensiveness by suppressing simulations of feared events may thus be an effective coping strategy, suggesting that a deficiency in this mechanism could contribute to the development of anxiety.

Belief, delusion, hypnosis, and the right dorsolateral prefrontal cortex: A transcranial magnetic stimulation study

Cortex ◽  
2018 ◽  
Vol 101 ◽  
pp. 234-248 ◽  
Author(s):  
Max Coltheart ◽  
Rochelle Cox ◽  
Paul Sowman ◽  
Hannah Morgan ◽  
Amanda Barnier ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Dorsolateral Prefrontal ◽  
The Right
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