In this study, we systematically tested the hypothesis that during the critical developmental period of adolescence, on a macro scale, the concentrations of major excitatory and inhibitory neurotransmitters (glutamate/glutamine and γ‑aminobutyric acid [GABA]) in the dorsal and ventral lateral prefrontal cortex are associated with the brain's functional connectivity and an individual's psychopathology. Neurotransmitters were measured via magnetic resonance spectroscopy while functional connectivity was measured with resting-state fMRI (n = 121). Seed-based and network-based analyses revealed associations of neurotransmitter concentrations and functional connectivities between regions/networks that are connected to prefrontal cortices via structural connections that are thought to be under dynamic development during adolescence. These regions tend to be boundary areas between functional networks. Furthermore, several connectivities were found to be associated with individual's levels of internalizing psychopathology. These findings provide insights into specific neurochemical mechanisms underlying the brain's macroscale functional organization, its development during adolescence, and its potential associations with symptoms associated with internalizing psychopathology.
Humans ; Adolescent ; Glutamic Acid/metabolism* ; Prefrontal Cortex/diagnostic imaging* ; Male ; Glutamine/metabolism* ; Female ; gamma-Aminobutyric Acid/metabolism* ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; Nerve Net/metabolism* ; Neural Pathways ; Connectome

The ZNF804A variant rs1344706 has consistently been associated with schizophrenia and plays a role in hippocampal-prefrontal functional connectivity during working memory. Whether the effect exists in the resting state and in patients with schizophrenia remains unclear. In this study, we investigated the ZNF804A polymorphism at rs1344706 in 92 schizophrenic patients and 99 healthy controls of Han Chinese descent, and used resting-state functional magnetic resonance imaging to explore the functional connectivity in the participants. We found a significant main effect of genotype on the resting-state functional connectivity (RSFC) between the hippocampus and the dorsolateral prefrontal cortex (DLPFC) in both schizophrenic patients and healthy controls. The homozygous ZNF804A rs1344706 genotype (AA) conferred a high risk of schizophrenia, and also exhibited significantly decreased resting functional coupling between the left hippocampus and right DLPFC (F(2,165) = 13.43, P < 0.001). The RSFC strength was also correlated with cognitive performance and the severity of psychosis in schizophrenia. The current findings identified the neural impact of the ZNF804A rs1344706 on hippocampal-prefrontal RSFC associated with schizophrenia.
Adult ; Analysis of Variance ; Female ; Functional Laterality ; genetics ; Genotype ; Hippocampus ; diagnostic imaging ; Humans ; Image Processing, Computer-Assisted ; Kruppel-Like Transcription Factors ; genetics ; Magnetic Resonance Imaging ; Male ; Neural Pathways ; diagnostic imaging ; Neuropsychological Tests ; Oxygen ; blood ; Polymorphism, Single Nucleotide ; genetics ; Prefrontal Cortex ; diagnostic imaging ; Psychiatric Status Rating Scales ; Schizophrenia ; diagnostic imaging ; genetics ; physiopathology ; Severity of Illness Index ; Young Adult

OBJECT: Nicotine dependence is the most common substance abuse disorder. One of the characteristics of nicotine dependence is craving. Regional activation of the brain induced by craving for nicotine was evaluated by using functional magnetic resonance imaging to investigate neuroanatomical site of smoking craving. METHOD: A smoker who satisfied DSM-IV criteria for nicotine dependence and a non smoker was studied. MRI data were acquired on a 1.5T Magnetom Vision Plus with a head volume coil. Two sets of visual stimuli were presented to subjects in a random manner. One was the film scenes of inducing smoking craving and the other was neutral stimuli not related to smoking. There were two fMRI sessions before and after smoking or sham smoking. Data were analyzed using SPM99. RESULTS: fMRI showed significant activated area in anterior cingulate and medial frontal lobes in the smoker during smoking craving. Right dorsolateral prefrontal cortex and parietal lobes were activated in the control during visual stimulation before smoking. After smoking, there was no brain activation during visual stimulation in both of smoker and non smoker. CONCLUSION: Metabolic activity of the anterior cingulate and medial frontal lobes increased during craving for smoking. This result suggests that fMRI may be a valuable tool in the identification of neurobiological process of craving.
Brain ; Diagnostic and Statistical Manual of Mental Disorders ; Frontal Lobe ; Head ; Magnetic Resonance Imaging* ; Nicotine ; Parietal Lobe ; Photic Stimulation ; Prefrontal Cortex ; Smoke* ; Smoking* ; Substance-Related Disorders ; Tobacco Use Disorder

OBJECTIVES: Neurobiological models for obsessive-compulsive disorder(OCD) have consistently implicated prefrontal-striatal circuits in the pathophysiology of this disorder. But, prior studies have inconsistently found alteration in caudate and frontal lobe volumes in patients with OCD. This study was undertaken in the hope that semi-automated linear transformation methods would elucidate the morphometric differences of various parts of brain between OCD and normal control group. METHODS: Thirteen patients meeting the DSM-IV criteria for OCD, and 9 psychiatrically normal comparison subjects participated in the study. 3-D brain MRIs using Spoiled gradient-recalled (SPGR) sequence were acquired for each subjects. After spatially normalized according to Talairach and Tournoux's coordinates, the gray and white matters were segmented by semiautomated methods using fuzzy algorithm. Each lobal volumes was measured according to Talairach and Tournoux's coordinates, and the region of interests of caudate nuclei was manually traced. The frontal lobe was divided into 3 subregions; dorsolateral prefrontal cortex, orbital frontal cortex, mesial frontal cortex accoring to the coordinates and Broadman's cytoarchitectonics. RESULTS: Only the volume of left and right frontal gray matter showed a significant difference between OCD and normal subjects. In OCD, the frontal gray matter volume was increased in tendency. There's no difference in laterality and no coorelation with clinical severities. CONCLUSION: Findings of increased frontal gray matter volumes in patients implicate a structural abnormality of these brain regions in the pathophysiology of OCD. The increased frontal gray matter volumes reflect a epiphenomena due to increased cerebral blood flows and metabolic rates before the structural changes may occur.
Brain* ; Caudate Nucleus ; Diagnostic and Statistical Manual of Mental Disorders ; Frontal Lobe ; Hope ; Humans ; Magnetic Resonance Imaging* ; Obsessive-Compulsive Disorder* ; Orbit ; Prefrontal Cortex