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Start Over Author "Ariel Graff" Journal biological psychiatry
35 results on '"Ariel Graff"'

3. 435. Increased Regional Cerebral Blood Flow Was Associated with Improved Illness Awareness Following 20 Sessions of TDCS in Patients With Schizophrenia

Author

Jianmeng Song, Julia Kim, Sofia Chavez, Yusuke Iwata, Fumihiko Ueno, Edgardo Torres Carmona, Yasaman Kambari, Aron Amaev, Ali Abdolizadeh, Teruki Koizumi, Vincenzo De Luca, Daniel M. Blumberger, Gary Remington, Bruce G. Pollock, Ariel Graff-Guerrero, and Philip Gerretsen

Subjects
Biological Psychiatry
Published
2023
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12. P549. MRI Neuromelanin Accumulation in Patients with Treatment-Resistant Schizophrenia: A Cross-Sectional Pilot Study

Author

Fumihiko Ueno, Yusuke Iwata, Shinichiro Nakajima, Sofia Chavez, Fernando Caravaggio, Guillermo Horga, Clifford Cassidy, Edgardo Torres-Carmona, Jianmeng Song, Vincenzo de Luca, Sakiko Tsugawa, Sho Moriguchi, Yoshihiro Noda, Mahavir Agarwal, Gary Remington, Philip Gerretsen, and Ariel Graff-Guerrero

Subjects
Biological Psychiatry
Published
2022
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14. P550. GABA Alteration in Patients With Treatment-Resistant Schizophrenia: A 1H-MRS Study

Author

Fumihiko Ueno, Shinichiro Nakajima, Yusuke Iwata, Shiori Honda, Julia Kim, Fernando Caravaggio, Eric Brown, Edgardo Torres-Carmona, Wanna Mar, Nathan Chan, Sakiko Tsugawa, Peter Truong, Eric Plitman, Yoshihiro Noda, Masaru Mimura, Napapon Sailasuta, Vincenzo de Luca, Gary Remington, Philip Gerretsen, and Ariel Graff-Guerrero

Subjects
Biological Psychiatry
Published
2022
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15. Prefrontal and Striatal Gamma-Aminobutyric Acid Levels and the Effect of Antipsychotic Treatment in First-Episode Psychosis Patients

Author

Ariel Graff-Guerrero, Helgi Jung-Cook, Francisco Reyes-Madrigal, Camilo de la Fuente-Sandoval, Dikoma C. Shungu, Rodolfo Solís-Vivanco, Oscar Rodríguez-Mayoral, Pablo León-Ortiz, and Xiangling Mao

Subjects
Adult, Male, Psychosis, medicine.medical_specialty, Adolescent, Proton Magnetic Resonance Spectroscopy, Glutamic Acid, Prefrontal Cortex, Antipsychotic treatment, gamma-Aminobutyric acid, Young Adult, 03 medical and health sciences, 0302 clinical medicine, First episode psychosis, Internal medicine, medicine, Humans, Prefrontal cortex, gamma-Aminobutyric Acid, Biological Psychiatry, Psychiatric Status Rating Scales, First episode, Aspartic Acid, Risperidone, business.industry, medicine.disease, Magnetic Resonance Imaging, Corpus Striatum, 030227 psychiatry, Endocrinology, Psychotic Disorders, nervous system, Schizophrenia, Female, business, 030217 neurology & neurosurgery, Antipsychotic Agents, medicine.drug
Abstract

Background Abnormally elevated levels of gamma-aminobutyric acid (GABA) in the medial prefrontal cortex (mPFC) have been reported in antipsychotic-free patients with schizophrenia. Whether such GABA elevations are also present in other brain regions and persist after antipsychotic treatment has not been previously investigated. Methods Twenty-eight antipsychotic-naive patients with first-episode psychosis (FEP) and 18 healthy control subjects completed the study. Following baseline proton magnetic resonance spectroscopy scans targeting the mPFC and a second region, the dorsal caudate, patients with FEP were treated with oral risperidone for 4 weeks at an initial dose of 1 mg/day that was titrated as necessary based on clinical judgment. After the 4-week treatment period, both groups were brought back to undergo outcome magnetic resonance spectroscopy scans, which were identical to the scans conducted at baseline. Results At baseline, higher GABA levels were found both in the mPFC and in the dorsal caudate of patients with FEP compared with healthy control subjects. Following 4 weeks of antipsychotic treatment, GABA levels in patients with FEP decreased relative to baseline in the mPFC, but decreased only at the trend level relative to baseline in the dorsal caudate. For either brain region, GABA levels at 4 weeks or posttreatment did not differ between patients with FEP and healthy control subjects. Conclusions The results of the present study documented elevations of GABA levels both in the mPFC and, for the first time, in the dorsal caudate of antipsychotic-naive patients with FEP, which normalized in both regions following 4 weeks of antipsychotic treatment.

Published
2018
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16. GWAS Analysis of Insight in Schizophrenia

Author

Philip Gerretsen, Christopher Adanty, Gary Remington, Ali Bani-Fatemi, Julia Kim, Ariel Graff-Guerrero, Gopal Shrestha, and Vincenzo De Luca

Subjects
medicine.medical_specialty, business.industry, Schizophrenia (object-oriented programming), Medicine, Genome-wide association study, business, Psychiatry, Biological Psychiatry
Published
2021
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19. Cortical Thickness in Patients With Schizophrenia With Impaired Insight Into Illness

Author

Eric Plitman, Vincenzo De Luca, Ariel Graff-Guerrero, Yasaman Kambari, Parita Shah, Jianmeng Song, Julia Kim, Eric E. Brown, Gary Remington, Fernando Caravaggio, Yusuke Iwata, M. Mallar Chakravarty, Philip Gerretsen, and Shinichiro Nakajima

Subjects
medicine.medical_specialty, business.industry, Schizophrenia (object-oriented programming), Impaired insight, Medicine, In patient, Audiology, business, Biological Psychiatry
Published
2021
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20. Neuromelanin Accumulation in Patients With Schizophrenia: A Systematic Review and Meta-Analysis

Author

Julia Kim, Ariel Graff-Guerrero, Shinichiro Nakajima, Fernando Caravaggio, Fumihiko Ueno, Yusuke Iwata, Philip Gerretsen, Edgardo Torres Carmona, and Sofia Chavez

Subjects
Oncology, medicine.medical_specialty, Neuromelanin, business.industry, Meta-analysis, Schizophrenia (object-oriented programming), Internal medicine, medicine, In patient, business, Biological Psychiatry
Published
2021
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21. Linking Clozapine/Norclozapine Ratio with Glial Marker in Patients With Treatment Resistant Schizophrenia

Author

Ariel Graff-Guerrero, Edgardo Torres Carmona, Sofia Chavez, Gary Remington, Julia Kim, Shinichiro Nakajima, Philip Gerretsen, Fumihiko Ueno, Yusuke Iwata, Wanna Mar, and Fernando Caravaggio

Subjects
Clozapine+Norclozapine, business.industry, Medicine, Treatment resistant schizophrenia, In patient, Pharmacology, business, Biological Psychiatry
Published
2021
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22. Metformin for Early Onset Comorbid Type 2 Diabetes or Prediabetes in Schizophrenia Spectrum Disorders: A Double-Blind Randomized Pilot Study

Author

Margaret Hahn, Gary Remington, MacKenzie Nicole, Ariel Graff-Guerrero, Araba Chintoh, Kenya A. Costa-Dookhan, Aristotle N. Voineskos, Quinn Cauccio-Treen, Eyesha Hashim, Panda Roshni, Anish Kirpalani, Sri Mahavir Agarwal, Caroline K. Kramer, and Fernando Caravaggio

Subjects
Pediatrics, medicine.medical_specialty, business.industry, Type 2 diabetes, medicine.disease, Metformin, Double blind, medicine, Prediabetes, business, Biological Psychiatry, Early onset, medicine.drug, Schizophrenia spectrum
Published
2020
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23. Improving Insight in Non-Treatment-Resistant Patients With Schizophrenia With Transcranial Direct Current Stimulation

Author

Parita Shah, Ariel Graff-Guerrero, Eric Plitman, Yusuke Iwata, Vincenzo De Luca, Julia Kim, Gary Remington, Philip Gerretsen, and Fernando Caravaggio

Subjects
Transcranial direct-current stimulation, business.industry, Schizophrenia (object-oriented programming), medicine.medical_treatment, Medicine, business, Treatment resistant, Neuroscience, Biological Psychiatry
Published
2020
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24. S167. Increased N-Acetylaspartate and Myo-Inositol Levels in Clozapine-Responders and Clozapine-Resistant Patients With Schizophrenia

Author

Ariel Graff-Guerrero, Gary Remington, Fernando Caravaggio, Julia Kim, Wanna Mar, Yusuke Iwata, Edgardo Torres Carmona, Parita Shah, Eric D. Brown, Shinichiro Nakajima, Philip Gerretsen, Sofias Chavez, and Eric Plitman

Subjects
medicine.medical_specialty, business.industry, medicine.disease, chemistry.chemical_compound, Endocrinology, chemistry, Schizophrenia, Internal medicine, medicine, Inositol, business, N-acetylaspartate, Biological Psychiatry, Clozapine, medicine.drug
Published
2019
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25. S185. Treatment Response Trajectories in Treatment-Resistant Schizophrenia: A Chart Review Study

Author

Parita Shah, Shinichiro Nakajima, Ariel Graff-Guerrero, Yusuke Iwata, Julia Kim, Hiroyoshi Takeuchi, Fernando Caravaggio, Marcos Sanches, Gary Remington, Philip Gerretsen, Margaret Hahn, and Eric D. Brown

Subjects
Treatment response, Pediatrics, medicine.medical_specialty, business.industry, Chart review, medicine, Treatment resistant schizophrenia, business, Biological Psychiatry
Published
2019
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26. Ventral Striatum Binding of a Dopamine D2/3 Receptor Agonist But Not Antagonist Predicts Normal Body Mass Index

Author

Sofia Raitsin, Shinichiro Nakajima, Fernando Caravaggio, Ariel Graff-Guerrero, Alan A. Wilson, and Philip Gerretsen

Subjects
Adult, Male, Agonist, medicine.medical_specialty, medicine.drug_class, Article, Body Mass Index, Young Adult, Internal medicine, Dopamine receptor D2, medicine, Humans, Carbon Radioisotopes, Radionuclide Imaging, Receptor, Biological Psychiatry, Sensitization, Raclopride, medicine.diagnostic_test, Receptors, Dopamine D2, Chemistry, Ventral striatum, Receptors, Dopamine D3, Antagonist, Middle Aged, medicine.anatomical_structure, Endocrinology, Positron emission tomography, Dopamine Agonists, Ventral Striatum, Dopamine Antagonists, Female, Radiopharmaceuticals, medicine.drug
Abstract

Positron emission tomography research has shown that dopamine D2/3 receptor (D2/3R) availability is negatively correlated with body mass index (BMI) in obese but not in healthy subjects. However, previous positron emission tomography studies have not looked specifically at the ventral striatum (VS), which plays an important role in motivation and feeding. Furthermore, these studies have only used antagonist radiotracers. Normal-weight rats given free access to high-fat diets demonstrate behavioral sensitization to D2/3R agonists but not to antagonists. Sensitization is associated with increased D2/3R affinity, which affects binding of agonists but not antagonists.We examined the association between BMI within the nonobese range (18.6-27.8) and D2/3R availability in the VS with the use of the agonist radiotracer [(11)C]-(+)-PHNO (n = 26) and the antagonist [(11)C]-raclopride (n = 35) in healthy humans.In the VS, we found a positive correlation between BMI and [(11)C]-(+)-PHNO binding but no relationship with [(11)C]-raclopride binding. Secondary analyses revealed no relationship between BMI and binding in the dorsal striatum with either radiotracer.We propose that in nonobese individuals, higher BMI may be associated with increased D2R affinity in the VS. This increased affinity may potentiate the incentive salience of food cues and counteract the effects of satiety cues, thereby increasing feeding.

Published
2015
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27. F182. Improving Insight into Psychosis With Transcranial Direct Current Stimulation in Schizophrenia

Author

Eric Plitman, Julia Kim, Gary Remington, Parita Shah, Ariel Graff-Guerrero, Philip Gerretsen, Fernando Caravaggio, Yusuke Iwata, and Vincenzo De Luca

Subjects
Psychosis, Transcranial direct-current stimulation, business.industry, Schizophrenia, medicine.medical_treatment, medicine, business, medicine.disease, Neuroscience, Biological Psychiatry
Published
2019
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28. T199. Assessing Neurometabolite Alterations in the Anterior Cingulate Cortex of Patients With Schizophrenia: A Multi-Site Proton Magnetic Resonance Spectroscopy Initiative

Author

Ariel Graff-Guerrero, Ryosuke Tarumi, Saashi A Bedford, Gabriel A. Devenyi, Shinichiro Nakajima, Yusuke Iwata, Jamie Near, Yoshihiro Noda, M. Mallar Chakravarty, Camilo de la Fuente-Sandoval, Eric Plitman, and Sakiko Tsugawa

Subjects
medicine.anatomical_structure, Nuclear magnetic resonance, Schizophrenia, business.industry, medicine, Multi site, medicine.disease, Spectroscopy, business, Biological Psychiatry, Anterior cingulate cortex, Proton magnetic resonance
Published
2019
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31. F230. Glutamatergic Neurometabolite Levels in Patients With Treatment-Resistant Schizophrenia: A Cross-Sectional 3T Proton MRS Study

Author

Yusuke Iwata, Nathan Chan, Gary Remington, Philip Gerretsen, Eric Plitman, Eric D. Brown, Ariel Graff-Guerrero, Jun Ku Chung, Shinichiro Nakajima, Sofias Chavez, Parita Shah, Julia Kim, Masaru Mimura, and Fernando Caravaggio

Subjects
Oncology, medicine.medical_specialty, Glutamatergic, business.industry, Internal medicine, medicine, In patient, Treatment resistant schizophrenia, business, Proton mrs, Biological Psychiatry
Published
2018
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32. F6. Is it Possible to Elicit Progressive Functioning Decline Without Having Beta-Amyloid Pathology? Clinical Trajectories of Mild Cognitive Impairment With Suspected Non-Alzheimer's Pathology

Author

Shunichiro Shinagawa, Julia Kim, Yusuke Iwata, Hiroyoshi Takeuchi, Ariel Graff-Guerrero, Philip Gerretsen, Shinichiro Nakajima, Fernando Caravaggio, Jun Ku Chung, Eric Plitman, Raihaan Patel, M. Mallar Chakravarty, and Antonio P. Strafella

Subjects
Amyloid pathology, Pathology, medicine.medical_specialty, business.industry, Medicine, business, Cognitive impairment, Beta (finance), Biological Psychiatry
Published
2018
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33. T154. Electroconvulsive Therapy Induces Age-Dependent Volume Increase in the Human Dentate Gyrus

Author

Eric Plitman, Taishiro Kishimoto, Bun Yamagata, Jun Ku Chung, Ariel Graff-Guerrero, Akihiro Takamiya, Kyosuke Sawada, Jinichi Hirano, Masaru Mimura, and M. Mallar Chakravarty

Subjects
medicine.medical_specialty, business.industry, Dentate gyrus, medicine.medical_treatment, Age dependent, 030227 psychiatry, 03 medical and health sciences, 0302 clinical medicine, Endocrinology, Electroconvulsive therapy, Volume (thermodynamics), Internal medicine, Medicine, business, 030217 neurology & neurosurgery, Biological Psychiatry
Published
2018
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35. Temporal difference modeling of the blood-oxygen level dependent response during aversive conditioning in humans: effects of dopaminergic modulation

Author

Ariel Graff-Guerrero, Shitij Kapur, Adrian P. Crawley, Mahesh Menon, Mark A. Smith, Jimmy Jensen, and Irina Vitcu

Subjects
Adult, Male, Time Factors, Adolescent, Dopamine, Conditioning, Classical, behavioral disciplines and activities, Dopamine Uptake Inhibitors, Neural Pathways, medicine, Image Processing, Computer-Assisted, Humans, Amphetamine, Biological Psychiatry, Blood-oxygen-level dependent, Putamen, Ventral striatum, Ventral Tegmental Area, Classical conditioning, Galvanic Skin Response, Middle Aged, Magnetic Resonance Imaging, Electric Stimulation, Ventral tegmental area, Oxygen, Substantia Nigra, medicine.anatomical_structure, Globus pallidus, nervous system, Dopamine Antagonists, Haloperidol, Female, Psychology, Neuroscience, Reinforcement, Psychology, psychological phenomena and processes, medicine.drug
Abstract

Background The prediction error (PE) hypothesized by the temporal difference model has been shown to correlate with the phasic activity of dopamine neurons during reward learning and the blood-oxygen level dependent (BOLD) response during reward and aversive conditioning tasks. We hypothesized that dopamine would modulate the PE related signal in aversive conditioning and that haloperidol would reduce PE related activity, while an acute dose of amphetamine would increase PE related activity in the ventral striatum. Methods Healthy participants took an acute dose of amphetamine, haloperidol, or placebo. We used functional magnetic resonance imaging (fMRI) to measure the BOLD signal while they carried out an aversive conditioning task, using cutaneous electrical stimulation as the unconditioned stimulus (US) and yellow and blue circles as conditioned stimulus (CS+ and CS−, respectively). Results Prediction error related BOLD activity was seen only in the ventral striatum in the placebo subjects. The subjects given amphetamine showed a wider network of PE related BOLD activity, including the ventral striatum, globus pallidus, putamen, insula, anterior cingulate, and substantia nigra/ventral tegmental area. Haloperidol subjects did not show PE related activity in any of these regions. Conclusions Our results provide the first demonstration that the modulation of dopamine transmission affects both the physiological correlates and PE related BOLD activity during aversive learning.

Published
2006

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