title: Alterations in brain metabolism and function following administration of low-dose codeine phosphate:1H-magnetic resonance spectroscopy and resting-state functional magnetic resonance imaging studies.
abstract: The aim of the present study was to identify alterations in brain function following administration of a single, low-dose of codeine phosphate in healthy volunteers using resting-state functional magnetic resonance imaging (fMRI). In addition, the metabolic changes in the two sides of the frontal lobe were identified using1H-magnetic resonance spectroscopy (1H-MRS). A total of 20 right-handed healthy participants (10 males, 10 females) were evaluated, and a Signa HDx 1.5T MRI scanner was used for data acquisition. An echo planar imaging sequence was used for resting-state fMRI, whereas a point resolved spectroscopy sequence was used for1H-MRS. Regional Saturation Technique, Data Processing Assistant for Resting-State fMRI, and Statistical Parameter Mapping 8 were used to analyze the fMRI data. The1H-MRS data were analyzed using LCModel software. At 1 h after oral administration of codeine phosphate (1.0 mg/kg), the amplitude of low-frequency fluctuation (ALFF) and regional homogeneity were altered in different brain areas. The choline content was significantly increased in the right and left frontal lobes following codeine phosphate administration (P=0.02 and P=0.03, respectively), whereas the inositol content was significantly decreased in the left frontal lobe (P=0.02). There was no change in the glutamic acid content in the frontal lobes. In conclusion, the functions of different brain regions can be affected by a single, low-dose administration of codeine phosphate. The alterations in metabolite content in the two frontal lobes may be associated with changes in brain function, whereas the ALFF in the globus pallidus may have an effect on codeine phosphate addiction. Finally, glutamic acid may be useful in the estimation of codeine dependence.
authors.affiliation: Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Cao
authors.affiliation: Department of Medical Imaging, The First Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China.
authors.forename: Pei-Yin
authors.initials: PY
authors.lastname: Lin
authors.affiliation: Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China.
authors.forename: Zhi-Wei
authors.initials: ZW
authors.lastname: Shen
authors.affiliation: Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China.
authors.forename: Ren-Hua
authors.initials: RH
authors.lastname: Wu
authors.affiliation: Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China.
authors.forename: Ye-Yu
authors.initials: YY
authors.lastname: Xiao
keywords: brain function; codeine phosphate; magnetic resonance spectroscopy; metabolite changes; resting-state functional magnetic resonance imaging