Andy R Eugene1, Jolanta Masiak2, Jacek Kapica3, Marek Masiak2, Richard M Weinshilboum1. 1. Department of Molecular Pharmacology and Experimental Therapeutics, Division of Clinical Pharmacology, Gonda 19, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA. 2. Department of Psychiatry, Medical University of Lublin, ul. Gluska 1 (SPSK Nr 1), Lublin 20-439, Poland. 3. Department of Electrical Engineering and Measurement Systems, University of Life Sciences in Lublin, 13 Akademicka Street, Lublin 20-950, Poland.
Abstract
INTRODUCTION: The purpose of this electrophysiological neuroimaging study was to provide a deeper mechanistic understanding of both olanzapine and risperidone pharmacodynamics relative to gender. In doing so, we age-matched 22 men and women and evaluated their resting-state EEG recordings and later used standard low resolution brain Electrotomography to visualize the differences in brain activity amongst the two patient groups. METHODS: In this investigation, electroencephalogram (EEG) data were analyzed from male and female schizophrenia patients treated with either olanzapine or risperidone, both atypical antipsychotics, during their in-patient stay at the Department of Psychiatry. Twenty-two males and females were age-matched and EEG recordings were analyzed from 19 Ag/AgCl electrodes. Thirty-seconds of resting EEG were spectrally transformed in standardized low resolution electromagnetic tomography (sLORETA). 3D statistical non-paramentric maps for the sLORETA Global Field Power within each band were finally computed. RESULTS: The results indicated that, relative to males patients, females schizophrenia patients had increased neuronal synchronization in delta frequency, slow-wave, EEG band located in the dorsolateral prefrontal cortex, within the middle frontal gyrus (t= -2.881, p < 0.03580). These findings suggest that females experience greater dopamine (D2) receptor and serotonin (5-HT2) receptor neuronal blockade relative to age-matched males. Further, our finding provided insight to the pharmacodynamics of second-generation antipsychotics olanzapine and risperidone. CONCLUSION: When compared to male patients, female patients, suffering from schizophrenia, have D2 and 5-HT2 receptors that are blocked more readily than age-matched male schizophrenia patients. Clinically, this may translate into a quicker time to treatment-response in females as compared to male patients.
INTRODUCTION: The purpose of this electrophysiological neuroimaging study was to provide a deeper mechanistic understanding of both olanzapine and risperidone pharmacodynamics relative to gender. In doing so, we age-matched 22 men and women and evaluated their resting-state EEG recordings and later used standard low resolution brain Electrotomography to visualize the differences in brain activity amongst the two patient groups. METHODS: In this investigation, electroencephalogram (EEG) data were analyzed from male and female schizophreniapatients treated with either olanzapine or risperidone, both atypical antipsychotics, during their in-patient stay at the Department of Psychiatry. Twenty-two males and females were age-matched and EEG recordings were analyzed from 19 Ag/AgCl electrodes. Thirty-seconds of resting EEG were spectrally transformed in standardized low resolution electromagnetic tomography (sLORETA). 3D statistical non-paramentric maps for the sLORETA Global Field Power within each band were finally computed. RESULTS: The results indicated that, relative to males patients, females schizophreniapatients had increased neuronal synchronization in delta frequency, slow-wave, EEG band located in the dorsolateral prefrontal cortex, within the middle frontal gyrus (t= -2.881, p < 0.03580). These findings suggest that females experience greater dopamine (D2) receptor and serotonin (5-HT2) receptor neuronal blockade relative to age-matched males. Further, our finding provided insight to the pharmacodynamics of second-generation antipsychotics olanzapine and risperidone. CONCLUSION: When compared to male patients, female patients, suffering from schizophrenia, have D2 and 5-HT2 receptors that are blocked more readily than age-matched male schizophreniapatients. Clinically, this may translate into a quicker time to treatment-response in females as compared to male patients.
Authors: John O Brooks; Jennifer C Hoblyn; Stephanie A Woodard; Allyson C Rosen; Terence A Ketter Journal: J Psychiatr Res Date: 2008-10-22 Impact factor: 4.791