scholarly journals M149. THE TOPOGRAPHY OF STRIATAL DOPAMINE AND SYMPTOMS IN PSYCHOSIS: AN INTEGRATIVE PET AND MRI STUDY

2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S192-S192
Author(s):  
Rob McCutcheon ◽  
Sameer Jauhar ◽  
Fiona Pepper ◽  
Matthew Nour ◽  
Maria Rogdaki ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Negative Symptoms ◽  
Striatal Dopamine ◽  
Psychotic Symptoms ◽  
Dopamine Synthesis ◽  
First Episode ◽  
Resting State Functional Connectivity ◽  
Positron Emission ◽  
Mri Study

Abstract Background Striatal dopamine dysfunction is proposed to underlie symptoms in psychosis, yet it is not known how changes in a single neurotransmitter could underlie the heterogenous presentations that are seen clinically. One hypothesis is that the symptomatic consequences of aberrant dopamine signalling may depend on where within the striatum dysfunction occurs. Positron emission tomography (PET) allows for the measurement of dopamine function across the striatum. However, when using typical atlas-based parcellation methods, the collinearity between measures of dopamine function within each striatal subdivision precludes investigation of this hypothesis. Methods We use a novel and data-driven parcellation method to address the above, and investigate relationships between spatial variability in dopamine synthesis capacity and psychotic symptoms. We employ a multimodal imaging approach combining 18F-DOPA PET and resting state MRI in 29 unmedicated and minimally-treated patients with first episode psychosis and 21 healthy controls. In each participant, we use resting state functional connectivity maps to quantify the functional connectivity of each striatal voxel to cortical networks. Network-specific striatal dopamine synthesis capacity (Kicer) was calculated for the resulting connectivity defined parcellations. Results Connectivity defined parcellations generated Kicer values with equivalent reliability, and significantly greater orthogonality to standard anatomical parcellation methods. Dopamine function within striatal areas connected to the default mode network is strongly associated with negative symptoms (p<0.001). Discussion These findings suggest that individual differences in the topography of striatal dopamine dysfunction contribute to shaping psychotic symptomatology.

scholarly journals Altered amygdala-based functional connectivity in individuals with attenuated psychosis syndrome and first-episode schizophrenia

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Woo-Sung Kim ◽  
Guangfan Shen ◽  
Congcong Liu ◽  
Nam-In Kang ◽  
Keon-Hak Lee ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Negative Relationship ◽  
First Episode ◽  
Frontal Pole ◽  
Resting State Functional Connectivity ◽  
Significant Group ◽  
Attenuated Psychosis Syndrome ◽  
The Right ◽  
First Episode Schizophrenia

Abstract Altered resting-state functional connectivity (FC) of the amygdala (AMY) has been demonstrated to be implicated in schizophrenia (SZ) and attenuated psychosis syndrome (APS). Specifically, no prior work has investigated FC in individuals with APS using subregions of the AMY as seed regions of interest. The present study examined AMY subregion-based FC in individuals with APS and first-episode schizophrenia (FES) and healthy controls (HCs). The resting state FC maps of the three AMY subregions were computed and compared across the three groups. Correlation analysis was also performed to examine the relationship between the Z-values of regions showing significant group differences and symptom rating scores. Individuals with APS showed hyperconnectivity between the right centromedial AMY (CMA) and left frontal pole cortex (FPC) and between the laterobasal AMY and brain stem and right inferior lateral occipital cortex compared to HCs. Patients with FES showed hyperconnectivity between the right superficial AMY and left occipital pole cortex and between the left CMA and left thalamus compared to the APS and HCs respectively. A negative relationship was observed between the connectivity strength of the CMA with the FPC and negative-others score of the Brief Core Schema Scales in the APS group. We observed different altered FC with subregions of the AMY in individuals with APS and FES compared to HCs. These results shed light on the pathogenetic mechanisms underpinning the development of APS and SZ.

scholarly journals O2.2. EVALUATION OF THE RELATIONSHIP BETWEEN GLUTAMATE AND BRAIN CONNECTIVITY IN ANTIPSYCHOTIC-NAïVE FIRST EPISODE PATIENTS – A COMBINED MAGNETIC RESONANCE SPECTROSCOPY AND RESTING STATE FUNCTIONAL CONNECTIVITY MRI STUDY

2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S4-S4
Author(s):  
Jose Maximo ◽  
Frederic Briend ◽  
William Armstrong ◽  
Nina Kraguljac ◽  
Adrienne Lahti
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Cingulate Cortex ◽  
Anterior Cingulate ◽  
Group Differences ◽  
First Episode ◽  
Resonance Spectroscopy ◽  
Resting State Functional Connectivity ◽  
Positive Correlations ◽  
Functional Connectivity Mri

Abstract Background Schizophrenia is thought to be a disorder of brain dysconnectivity. An imbalance between cortical excitation/inhibition is also implicated, but the link between these abnormalities remains unclear. The present study used resting state functional connectivity MRI (rs-fcMRI) and magnetic resonance spectroscopy (MRS) to investigate how measurements of glutamate + glutamine (Glx) in the anterior cingulate cortex (ACC) relate to rs-fcMRI in medication-naïve first episode psychosis (FEP) subjects compared to healthy controls (HC). Based on our previous findings, we hypothesized that in HC would show correlations between Glx and rs-fMRI in the salience and default mode network, but these relationships would be altered in FEP. Methods Data from 53 HC (age = 24.70 ±6.23, 34M/19F) and 60 FEP (age = 24.08 ±6.29, 38M/22F) were analyzed. To obtain MRS data, a voxel was placed in the ACC (PRESS, TR/TE = 2000/80ms). Metabolite concentrations were quantified with respect to internal water using the AMARES algorithm in jMRUI. rs-fMRI data were processed using a standard preprocessing pipeline in the CONN toolbox. BOLD signal from a priori brain regions of interest from posterior cingulate cortex (default mode network, DMN), anterior cingulate cortex (salience network, SN), and right posterior parietal cortex (central executive network, CEN) were extracted and correlated with the rest of the brain to measure functional connectivity (FC). Group analyses were performed on Glx, FC, and Glx-FC interactions while controlling for age, gender, and motion when applicable. FC and Glx-FC analyses were performed using small volume correction [(p < 0.01, threshold-free cluster enhancement corrected (TFCE)]. Results No significant between-group differences were found in Glx concentration in the ACC [F(1, 108) = 0.34, p = 0.56], but reduced FC was found on each network in FEP compared to HC (pTFCE corrected). Group Glx-FC interactions were found in the form of positive correlations between Glx and FC in DMN and SN in the HC group, but not in FEP; and negative correlations in CEN in HC, but not in FEP. Discussion While we did not find significant group differences in ACC Glx measurements, ACC Glx modulated FC differentially in FEP and HC. Positive correlations between Glx and FC were found in the SN and DMN, suggesting long range modulation of the two networks in HC, but not in FEP. Additionally, negative correlations between Glx and FC were found in CEN in HC, but not in FEP. Overall, these results suggest that even in the absence of group differences in Glx concentration, the long-range modulation of these 3 networks by ACC Glx is altered in FEP.

F232. Abnormality of Resting-State Functional Connectivity in Insular Cortex in Patients With First Episode Psychosis

2018 ◽  
Vol 83 (9) ◽  
pp. S329
Author(s):  
Hironori Kuga ◽  
Andreia Faria ◽  
Lindsay Shaffer ◽  
Jeff Crawford ◽  
Takanori Ohgaru ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Insular Cortex ◽  
First Episode Psychosis ◽  
First Episode ◽  
Resting State Functional Connectivity ◽  
Episode Psychosis
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