Imaging joy with generalized slice dithered enhanced resolution and SWAT reconstruction: 3T high spatial-temporal resolution fMRI.

To facilitate high spatial-temporal resolution fMRI (≦1mm) at more broadly available field strengths (3T) and to better understand the neural underpinnings of joy, we used SE-based generalized Slice Dithered Enhanced Resolution (gSLIDER). This sequence increases SNR efficiency utilizing sub-voxel shifts along the slice direction. To improve the effective temporal resolution of gSLIDER, we utilized the temporal information within individual gSLIDER RF encodings to develop gSLIDER with Sliding Window Accelerated Temporal resolution (gSLIDER-SWAT).

Highly accelerated submillimeter resolution 3D GRASE with controlled blurring in -weighted functional MRI at 7 Tesla: A feasibility study.

Purpose: To achieve highly accelerated submillimeter resolution -weighted functional MRI at 7T by developing a three-dimensional gradient and spin echo imaging (GRASE) with inner-volume selection and variable flip angles (VFA).

Methods: GRASE imaging has disadvantages in that (a) k-space modulation causes blurring by limiting the number of slices and (b) a VFA scheme results in partial success with substantial SNR loss. In this work, accelerated GRASE with controlled blurring is developed to improve a point spread function (PSF) and temporal signal-to-noise ratio (tSNR) with a large number of slices.

Relationships Between Altered Functional Magnetic Resonance Imaging Activation and Cortical Thickness in Patients With Euthymic Bipolar I Disorder.

Background: Performance during cognitive control functional magnetic resonance imaging (fMRI) tasks are associated with frontal lobe hypoactivation in patients with bipolar disorder, even while euthymic. Here, we study the structural underpinnings for this functional abnormality simultaneously with brain activation data.

Methods: In a sample of ninety adults (45 with inter-episode Bipolar I disorder and 45 healthy controls), we explored whether abnormal functional activation patterns in bipolar euthymic subjects during a Go-NoGo fMRI task are associated with regional deficits in cortical gray matter thickness in the same regions.

Frontal lobe hypoactivation in medication-free adults with bipolar II depression during response inhibition.

In executive function, specifically in response inhibition, numerous studies support the essential role for the inferior frontal cortex (IFC). Hypoactivation of the IFC during response-inhibition tasks has been found consistently in subjects with bipolar disorder during manic and euthymic states. The aim of this study was to examine whether reduced IFC activation also exists in unmedicated subjects with bipolar disorder during the depressed phase of the disorder.

Differences in resting corticolimbic functional connectivity in bipolar I euthymia.

Objective:   We examined resting state functional connectivity in the brain between key emotion regulation regions in bipolar I disorder to delineate differences in coupling from healthy subjects.

Methods:   Euthymic subjects with bipolar I disorder (n = 20) and matched healthy subjects (n = 20) participated in a resting state functional magnetic resonance imaging scan. Low-frequency fluctuations in blood oxygen level-dependent (BOLD) signal were correlated in the six connections between four anatomically defined nodes: left and right amygdala and left and right ventrolateral prefrontal cortex (vlPFC).

Frontostriatal neuroimaging findings differ in patients with bipolar disorder who have or do not have ADHD comorbidity.

Background: The inferior frontal cortical (IFC)-striatal network plays an integral role in response inhibition and is compromised in patients with Bipolar Disorder (BP) or Attention-Deficit/Hyperactivity Disorder (ADHD). Prior BP functional neuroimaging studies have not accounted for ADHD comorbidity despite its high prevalence.

Methods: The authors conducted an fMRI study using a response inhibition task (Go-NoGo) in 32 euthymic adults with BP, half with comorbid ADHD (BP/ADHD); 16 adults with ADHD alone; and 30 healthy controls.

Frontal-amygdala connectivity alterations during emotion downregulation in bipolar I disorder.

Background: The symptoms of bipolar disorder suggest dysfunction of emotion regulatory networks. In healthy control populations, downregulation of emotional responses activates the ventral lateral prefrontal cortex (vlPFC) and dampens amygdala activation. This study investigated frontal and limbic function and connectivity during emotion downregulation in euthymic subjects with bipolar I disorder (BPI) and healthy control subjects.

Regional fMRI hypoactivation and altered functional connectivity during emotion processing in nonmedicated depressed patients with bipolar II disorder.

Objective: Although the amygdala and ventrolateral prefrontal cortex have been implicated in the pathophysiology of bipolar I disorder, the neural mechanisms underlying bipolar II disorder remain unknown. The authors examined neural activity in response to negative emotional faces during an emotion perception task that reliably activates emotion regulatory regions.

Method: Twenty-one nonmedicated depressed bipolar II patients and 21 healthy comparison subjects underwent functional MRI (fMRI) while performing an emotional face-matching task.

Deficits in inferior frontal cortex activation in euthymic bipolar disorder patients during a response inhibition task.

Objectives: The inferior frontal cortical-striatal network plays an integral role in response inhibition in normal populations. While inferior frontal cortex (IFC) impairment has been reported in mania, this study explored whether this dysfunction persists in euthymia.

Methods: Functional magnetic resonance imaging (fMRI) activation was evaluated in 32 euthymic patients with bipolar I disorder and 30 healthy subjects while performing the Go/NoGo response inhibition task.

The functional neuroanatomy of bipolar disorder: a consensus model.

Objectives: Functional neuroimaging methods have proliferated in recent years, such that functional magnetic resonance imaging, in particular, is now widely used to study bipolar disorder. However, discrepant findings are common. A workgroup was organized by the Department of Psychiatry, University of Cincinnati (Cincinnati, OH, USA) to develop a consensus functional neuroanatomic model of bipolar I disorder based upon the participants' work as well as that of others.

Anterior cingulate activation relates to local cortical thickness.

Few studies have examined the relationship between local anatomic thickness of the cortex and the activation signals arising from it. Using structural and functional MRI, we examined whether a relationship exists between cortical thickness and brain activation. Twenty-eight participants were asked to perform the Go/NoGo response inhibition task known to activate the anterior cingulate and the prefrontal cortex.

Normal amygdala activation but deficient ventrolateral prefrontal activation in adults with bipolar disorder during euthymia.

Functional neuroimaging studies have implicated the involvement of the amygdala and ventrolateral prefrontal cortex (vlPFC) in the pathophysiology of bipolar disorder. Hyperactivity in the amygdala and hypoactivity in the vlPFC have been reported in manic bipolar patients scanned during the performance of an affective faces task. Whether this pattern of dysfunction persists during euthymia is unclear.

Differential electrophysiological response during rest, self-referential, and non-self-referential tasks in human posteromedial cortex.

The electrophysiological basis for higher brain activity during rest and internally directed cognition within the human default mode network (DMN) remains largely unknown. Here we use intracranial recordings in the human posteromedial cortex (PMC), a core node within the DMN, during conditions of cued rest, autobiographical judgments, and arithmetic processing. We found a heterogeneous profile of PMC responses in functional, spatial, and temporal domains.

fMRI activation in the amygdala and the orbitofrontal cortex in unmedicated subjects with major depressive disorder.

Although amygdala and frontal lobe functional abnormalities have been reported in patients with mood disorders, the literature regarding major depressive disorder (MDD) is inconsistent. Likely confounds include heterogeneity of patient samples, medication status, and analytic approach. This study evaluated the amygdala and frontal lobe activation in unmedicated MDD patients.