Prefrontal cortex activity in people with schizophrenia and control subjects

1998 ◽  
Vol 172 (4) ◽  
pp. 316-323 ◽  
Author(s):  
Sean A. Spence ◽  
Steven R. Hirsch ◽  
David J. Brooks ◽  
Paul M. Grasby

BackgroundHypo-activation of the left dorsolateral prefrontal cortex is inconsistently found in neuroimaging studies of schizophrenia. As the left dorsolateral prefrontal cortex is involved in the generation of action, disordered function in this region may be implicated in schizophrenic symptomatology.MethodWe used H215O positron emission tomography to study dorsolateral prefrontal cortical function in men with schizophrenia (n=13) and male control subjects (n=6) performing joystick movements on two occasions, 4–6 weeks apart. The patients were initially in relapse. To clarify dorsolateral prefrontal cortical function we also scanned another group of control subjects (n=5) performing mouth movements.ResultsThe control subjects performing hand or mouth movements activated the left dorsolateral prefrontal cortex to a maximum when the movements were self-selected. The men with relapsed schizophrenia exhibited left dorsolateral prefrontal cortical hypo-activation, which remitted with symptomatic improvement.ConclusionsHypofrontality in these patients is a dynamic phenomenon across time, possibly related to current symptomatology. The most appropriate question about the presence of hypofrontality in schizophrenia may be when, rather than whether, it will occur.

2019 ◽  
Vol 45 (4) ◽  
pp. 694-702 ◽  
Author(s):  
Nicholas L. Balderston ◽  
Emily M. Beydler ◽  
Camille Roberts ◽  
Zhi-De Deng ◽  
Thomas Radman ◽  
...  

AbstractMuch of the mechanistic research on anxiety focuses on subcortical structures such as the amygdala; however, less is known about the distributed cortical circuit that also contributes to anxiety expression. One way to learn about this circuit is to probe candidate regions using transcranial magnetic stimulation (TMS). In this study, we tested the involvement of the dorsolateral prefrontal cortex (dlPFC), in anxiety expression using 10 Hz repetitive TMS (rTMS). In a within-subject, crossover experiment, the study measured anxiety in healthy subjects before and after a session of 10 Hz rTMS to the right dorsolateral prefrontal cortex (dlPFC). It used threat of predictable and unpredictable shock to induce anxiety and anxiety potentiated startle to assess anxiety. Counter to our hypotheses, results showed an increase in anxiety-potentiated startle following active but not sham rTMS. These results suggest a mechanistic link between right dlPFC activity and physiological anxiety expression. This result supports current models of prefrontal asymmetry in affect, and lays the groundwork for further exploration into the cortical mechanisms mediating anxiety, which may lead to novel anxiety treatments.


2019 ◽  
Vol 22 (7) ◽  
pp. 415-425 ◽  
Author(s):  
Per Stenkrona ◽  
Granville J Matheson ◽  
Christer Halldin ◽  
Simon Cervenka ◽  
Lars Farde

Abstract Background Positron emission tomography studies examining differences in D1-dopamine receptor binding between control subjects and patients with schizophrenia have been inconsistent, reporting higher, lower, and no difference in the frontal cortex. Exposure to antipsychotic medication has been suggested to be a likely source of this heterogeneity, and thus there is a need for studies of patients at early stages of the disorder who have not been exposed to such drugs. Methods Here, we compared 17 healthy control subjects and 18 first-episode neuroleptic naive patients with schizophrenia or schizophreniform psychosis using positron emission tomography and the D1-dopamine receptor radioligand [11C]SCH23390. Results We observed a statistically significant difference in the dorsolateral prefrontal cortex. Contrary to our expectations, patients had less D1-dopamine receptor availability with a moderate effect size. In a Bayesian analysis, we show that the data are over 50 times more likely to have occurred under the decrease as opposed to the increase hypothesis. This effect was not global, as our analysis showed that the null hypothesis was preferred over either hypothesis in the striatum. Conclusions This investigation represents the largest single sample of neuroleptic-naive patients examined for D1-dopamine receptor availability using PET and suggests a reduction of prefrontal D1-dopamine receptor density in the pathophysiology of schizophrenia. However, further work will be required to reach a consensus.


2021 ◽  
Vol 25 (1) ◽  
pp. 1-17
Author(s):  
Puladi Farzaneh ◽  
Bagheri Masood ◽  
Ghasem Askarizadeh ◽  
Afsaneh Moradi

The present study aimed to investigate whether working memory (WM) and planning performances can be enhanced using transcranial direct current stimulation (tDCS). A total of 30 healthy individuals were randomly assigned to two groups: active (A)-tDCS and control (S)-tDCS. Anodal stimulation over the left dorsolateral prefrontal cortex (DLPFC) (F3) and cathodal stimulation over the right orbitofrontal cortex (OFC) (FP2) were further implemented at 2 mA in the A-tDCS group, while there was no intervention in the control group. The tools used were software versions of the three-level n-back task and Tower of London (TOL) task, and for each task we measured participants’ response accuracy and response time. The results showed a significant difference between the groups in both cognitive functions, suggesting that tDCS can improve response accuracy in memory and problem-solving ability, but it is less effective in terms of improving response time on planning. Overall, findings suggest that tDCS can enhance WM and planning performances.


2005 ◽  
Vol 186 (3) ◽  
pp. 203-208 ◽  
Author(s):  
V. Molina ◽  
J. Sanz ◽  
S. Reig ◽  
R. Martínez ◽  
F. Sarramea ◽  
...  

BackgroundDecreased metabolic activity in the prefrontal cortex during cognitive activation is a recurrent finding and a likely functional marker of schizophrenia.AimsTo investigate the occurrence of hypofrontality in patients with first-episode psychosis, with or without evolution to schizophrenia.MethodWe used fluorodeoxyglucose positron emission tomography during the performance of an attention task and magnetic resonance imaging to study the dorsolateral prefrontal region in 13 men with a first episode of psychosis. Data from patients who progressed to schizophrenia were compared with those of patients who did not meet criteria for this diagnosis after 2 years.ResultsPatients who developed schizophrenia demonstrated a significant hypofrontality in the dorsolateral prefrontal cortex in comparison with the non-schizophrenia and control groups.ConclusionsOur results suggest that hypofrontality could be a marker of schizophrenia at the time of the first psychotic episode, in agreement with neurodevelopmental theories of schizophrenia.


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