The amygdala has been known to play a pivotal role in mediating fear-related responses including panic attacks. Given the functionally distinct role of the amygdalar subregions, morphometric measurements of the amygdala may point to the pathophysiological mechanisms underlying panic disorder. The current study aimed to determine the global and local morphometric alterations of the amygdala related to panic disorder.

The aim of the current study was to evaluate the relationship between quetiapine's effect on the improvement of mood symptoms in bipolar patients and brain metabolite level changes as measured by proton magnetic resonance spectroscopy ((1)H-MRS). Rapid cycling bipolar patients in the manic state were recruited and treated with quetiapine for 12 weeks. Clinical assessment was performed using the Young Mania Rating Scale (YMRS), the 17-item Hamilton Depression Rating Scale (HDRS) and the Clinical Global Impression-Severity scale (CGI-S) at baseline and weekly intervals during the 12-week period. In order to evaluate metabolite level changes over time, (1)H-MRS scans were acquired at baseline and week 12. There were significant reductions in YMRS scores (by 43.0%), HDRS scores (by 27.5%) and CGI-S score (by 44.6%) over the 12 week-period. Lactate levels significantly decreased over the 12-week study period (22.4%). This change in lactate levels was more prominent in quetiapine responders than in non-responders. Additionally, there was a positive correlation between changes in lactate levels and those in YMRS scores (r=0.52, p=0.003). Our findings suggest that quetiapine's antimanic and antidepressant efficacy in patients with rapid cycling bipolar disorder may potentially be related to decreased lactate levels in frontal regions of the brain.

Despite accumulating evidence of physiological abnormalities related to posttraumatic stress disorder (PTSD), the current diagnostic criteria for PTSD still rely on clinical interviews. In this study, we investigated the diagnostic potential of multimodal neuroimaging for identifying posttraumatic symptom trajectory after trauma exposure. Thirty trauma-exposed individuals and 29 trauma-unexposed healthy individuals were followed up over a 5-year period. Three waves of assessments using multimodal neuroimaging, including structural magnetic resonance imaging (MRI) and diffusion-weighted MRI, were performed. Based on previous findings that the structural features of the fear circuitry-related brain regions may dynamically change during recovery from the trauma, we employed a machine learning approach to determine whether local, connectivity, and network features of brain regions of the fear circuitry including the amygdala, orbitofrontal and ventromedial prefrontal cortex (OMPFC), hippocampus, insula, and thalamus could distinguish trauma-exposed individuals from trauma-unexposed individuals at each recovery stage. Significant improvement in PTSD symptoms was observed in 23%, 52%, and 88% of trauma-exposed individuals at 1.43, 2.68, and 3.91 years after the trauma, respectively. The structural features of the amygdala were found as major classifiers for discriminating trauma-exposed individuals from trauma-unexposed individuals at 1.43 years after the trauma, but these features were nearly normalized at later phases when most of the trauma-exposed individuals showed clinical improvement in PTSD symptoms. Additionally, the structural features of the OMPFC showed consistent predictive values throughout the recovery period. In conclusion, the current study provides a promising step forward in the development of a clinically applicable predictive model for diagnosing PTSD and predicting recovery from PTSD.

Adolescent-onset exposure to highly addictive substances such as opiates may induce far-reaching deleterious effects on later mental and physical health. However, little is known about the neurodevelopmental basis for adolescent-onset opiate dependence. Here we examined whether having an abnormally large cavum septum pellucidum (CSP), a putative marker of limbic structural maldevelopment, is associated with opiate dependence particularly beginning in adolescence.

In animal models of Parkinson's disease (PD), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is one of the most widely used agents that damages the nigrostriatal dopaminergic pathway. However, brain structural changes in response to MPTP remain unclear. This study aimed to investigate in vivo longitudinal changes in gray matter (GM) volume and white matter (WM) microstructure in primate models administered with MPTP. In six cynomolgus monkeys, high-resolution magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) scans were acquired 7 times over 32 weeks, and assessments of motor symptoms were conducted over 15 months, before and after the MPTP injection. Changes in GM volume and WM microstructure were estimated on a voxel-by-voxel basis. Mixed-effects regression models were used to examine the trajectories of these structural changes. GM volume initially increased after the MPTP injection and gradually decreased in the striatum, midbrain, and other dopaminergic areas. The cerebellar volume temporarily decreased and returned to its baseline level. The rate of midbrain volume increase was positively correlated with the increase rate of motor symptom severity (Spearman rho = 0.93, p = 0.008). Mean, axial, and radial diffusivity in the striatum and frontal areas demonstrated initial increases and subsequent decreases. The current multi-modal imaging study of MPTP-administered monkeys revealed widespread and dynamic structural changes not only in the nigrostriatal pathway but also in other cortical, subcortical, and cerebellar areas. Our findings may suggest the need to further investigate the roles of inflammatory reactions and glial activation as potential underlying mechanisms of these structural changes.

Although the neurobiological mechanisms underlying panic disorder (PD) are not yet clearly understood, increasing amount of evidence from animal and human studies suggests that the amygdala, which plays a pivotal role in neural network of fear and anxiety, has an important role in the pathogenesis of PD. This article aims to (1) review the findings of structural, chemical, and functional neuroimaging studies on PD, (2) relate the amygdala to panic attacks and PD development, (3) discuss the possible causes of amygdalar abnormalities in PD, (4) and suggest directions for future research.

The adolescent brain, with ongoing prefrontal maturation, may be more vulnerable to drug use-related neurotoxic changes as compared to the adult brain. We investigated whether the use of methamphetamine (MA), a highly addictive psychostimulant, during adolescence affect metabolic and cognitive functions of the anterior cingulate cortex (ACC). In adolescent MA users (n = 44) and healthy adolescents (n = 53), the levels of N-acetyl aspartate (NAA), a neuronal marker, were examined in the ACC using proton magnetic resonance spectroscopy. The Stroop color-word task was used to assess Stroop interference, which may reflect cognitive functions of behavior monitoring and response selection that are mediated by the ACC. Adolescent MA users had lower NAA levels in the ACC (t = -2.88, P = 0.005) and relatively higher interference scores (t = 2.03, P = 0.045) than healthy adolescents. Moreover, there were significant relationships between lower NAA levels in the ACC and worse interference scores in adolescent MA users (r = -0.61, P < 0.001). Interestingly, early onset of MA use, as compared to late onset, was related to both lower NAA levels in the ACC (t = -2.24, P = 0.03) as well as lower performance on interference measure of the Stroop color-word task (t = 2.25, P = 0.03). The current findings suggest that metabolic dysfunction in the ACC and its related cognitive impairment may play an important role in adolescent-onset addiction, particularly during early adolescence.

The purpose of this study was to investigate the brain gamma-aminobutyric acid (GABA) concentration and its relationship with clinical variables in patients with panic disorder (PD). Single voxel proton magnetic resonance spectroscopy ((1)H-MRS) scan was performed on 22 medicated subjects with PD and 25 age and sex-matched healthy comparison subjects. GABA and other metabolite levels were measured in the anterior cingulate cortex (ACC) and basal ganglia. GABA levels were significantly lower in the ACC and basal ganglia of PD patients relative to comparison subjects. Lactate and choline concentrations in the ACC in PD patients were also higher than in the comparison subjects. Our data suggested in part that alterations of the GABA function and the energy metabolism in ACC and basal ganglia may play an important role in the pathophysiology of panic disorder.

Alcohol dependence is a serious disorder that can be related with a number of potential health-related and social consequences. Cortical thickness measurements would provide important information on the cortical structural alterations in patients with alcohol dependence. Twenty-one patients with alcohol dependence and 22 healthy comparison subjects have been recruited and underwent high-resolution brain magnetic resonance (MR) imaging and clinical assessments. T1-weighted MR images were analyzed using the cortical thickness analysis program. Significantly thinner cortical thickness in patients with alcohol dependence than healthy comparison subjects was noted in the left superior frontal cortical region, correcting for multiple comparisons and adjusting with age and hemispheric average cortical thickness. There was a significant association between thickness in the cluster of the left superior frontal cortex and the duration of alcohol use. The prefrontal cortical region may particularly be vulnerable to chronic alcohol exposure. It is also possible that the pre-existing deficit in this region may have rendered individuals more susceptible to alcohol dependence.

Type 1 diabetes mellitus (T1DM) usually begins in childhood and adolescence and causes lifelong damage to several major organs including the brain. Despite increasing evidence of T1DM-induced structural deficits in cortical regions implicated in higher cognitive and emotional functions, little is known whether and how the structural connectivity between these regions is altered in the T1DM brain. Using inter-regional covariance of cortical thickness measurements from high-resolution T1-weighted magnetic resonance data, we examined the topological organizations of cortical structural networks in 81 T1DM patients and 38 healthy subjects. We found a relative absence of hierarchically high-level hubs in the prefrontal lobe of T1DM patients, which suggests ineffective top-down control of the prefrontal cortex in T1DM. Furthermore, inter-network connections between the strategic/executive control system and systems subserving other cortical functions including language and mnemonic/emotional processing were also less integrated in T1DM patients than in healthy individuals. The current results provide structural evidence for T1DM-related dysfunctional cortical organization, which specifically underlie the top-down cognitive control of language, memory, and emotion.