Emotion regulation in emerging adults with major depressive disorder and frequent cannabis use.

In people with mental health issues, approximately 20% have co-occurring substance use, often involving cannabis. Although emotion regulation can be affected both by major depressive disorder (MDD) and by cannabis use, the relationship among all three factors is unknown. In this study, we used fMRI to evaluate the effect that cannabis use and MDD have on brain activation during an emotion regulation task.

Medial Prefrontal and Anterior Insular Connectivity in Early Schizophrenia and Major Depressive Disorder: A Resting Functional MRI Evaluation of Large-Scale Brain Network Models.

Anomalies in the medial prefrontal cortex, anterior insulae, and large-scale brain networks associated with them have been proposed to underlie the pathophysiology of schizophrenia and major depressive disorder (MDD). In this study, we examined the connectivity of the medial prefrontal cortices and anterior insulae in 24 healthy controls, 24 patients with schizophrenia, and 24 patients with MDD early in illness with seed-based resting state functional magnetic resonance imaging analysis using Statistical Probability Mapping. As hypothesized, reduced connectivity was found between the medial prefrontal cortex and the dorsal anterior cingulate cortex and other nodes associated with directed effort in patients with schizophrenia compared to controls while patients with MDD had reduced connectivity between the medial prefrontal cortex and ventral prefrontal emotional encoding regions compared to controls.

Unique functional abnormalities in youth with combined marijuana use and depression: an FMRI study.

Prior research has shown a relationship between early onset marijuana (MJ) use and depression; however, this relationship is complex and poorly understood. Here, we utilized passive music listening and fMRI to examine functional brain activation to a rewarding stimulus in 75 participants [healthy controls (HC), patients with major depressive disorder (MDD), frequent MJ users, and the combination of MDD and MJ (MDD + MJ)]. For each participant, a preferred and neutral piece of instrumental music was determined (utilizing ratings on a standardized scale), and each completed two 6-min fMRI scans of a passive music listening task.

Correlation of brain default mode network activation with bipolarity index in youth with mood disorders.

Background: Major Depressive Disorder (MDD) and Bipolar Disorder (BD) can be difficult to differentiate, as both feature depressive episodes. Here we have utilized fMRI and a measure of trait bipolarity to examine resting-state functional connectivity of brain activation in the default mode network in youth with MDD and BD to isolate trait-specific patterns.

Methods: We collected resting-state fMRI scans from thirty youth (15 MDD; 15 BD, Type 1).

Neural activity in primate caudate nucleus associated with pro- and antisaccades.

The basal ganglia (BG) play a central role in movement and it has been demonstrated that the discharge rate of neurons in these structures are modulated by the behavioral context of a given task. Here we used the antisaccade task, in which a saccade toward a flashed visual stimulus must be inhibited in favor of a saccade to the opposite location, to investigate the role of the caudate nucleus, a major input structure of the BG, in flexible behavior. In this study, we recorded extracellular neuronal activity while monkeys performed pro- and antisaccade trials.

BOLD fMRI activation for anti-saccades in nonhuman primates.

Most of our knowledge about the functional organization of the nonhuman primate brain has come from single neuron recordings, whereas functional magnetic resonance imaging (fMRI) has rapidly become the method of choice for the study of the human brain. In some cases these two methods have resulted in conflicting models of frontal lobe function. Based on the finding that the frontal eye fields (FEF) exhibit a higher blood-oxygenation-level dependent (BOLD) activation for anti-saccades compared with pro-saccades, it has been proposed that this area is more involved in voluntary than automatic saccade generation.

Development, characterization and transferability of microsatellite markers for the plant genus Phlox (Polemoniaceae).

In order to study diversification and microevolution in Phlox, we developed nine polymorphic microsatellite loci. In 20 individuals of Phlox pilosa from a single population, the average number of alleles per locus was 10.0 ± 5.

Inhibition and generation of saccades: rapid event-related fMRI of prosaccades, antisaccades, and nogo trials.

Flexible, adaptive behavior often requires the inhibition of automatic responses in favor of voluntary response generation. The antisaccade task requires active inhibition of the automatic saccade to a peripheral stimulus followed by generation of a voluntary antisaccade to the opposite location. Previous studies demonstrated greater functional magnetic resonance imaging (fMRI) activation for antisaccades than prosaccades in cortical saccade areas but did not distinguish the relative contributions of saccadic inhibition and generation.

Neural processes associated with antisaccade task performance investigated with event-related FMRI.

One of the hallmarks of cognitive control is the suppression of prepotent but inappropriate responses. Here we used event-related functional MRI to measure functional brain activation during a stimulus-response incompatibility task. Subjects were instructed before a stimulus appeared either to look at the stimulus (prosaccade) or to look away from the stimulus (antisaccade).

Effect of stimulus probability on anti-saccade error rates.

Subjects sometimes fail to suppress a reflexive saccade towards the flashed stimulus in an anti-saccade task. Here, we studied how error rates in the anti-saccade task varied as a function of saccadic probability. Ten subjects performed 200 anti-saccade trials for each of three saccade-direction probability conditions (20%, 50%, and 80%).