Rates of cerebral protein synthesis in primary visual cortex during sleep-dependent memory consolidation, a study in human subjects.

If protein synthesis during sleep is required for sleep-dependent memory consolidation, we might expect rates of cerebral protein synthesis (rCPS) to increase during sleep in the local brain circuits that support performance on a particular task following training on that task. To measure circuit-specific brain protein synthesis during a daytime nap opportunity, we used the L-[1-(11)C]leucine positron emission tomography (PET) method with simultaneous polysomnography. We trained subjects on the visual texture discrimination task (TDT).

Antidepressant efficacy of high and low frequency rTMS at 110% of motor threshold versus sham stimulation over left prefrontal cortex.

Background: While the efficacy of repetitive transcranial magnetic stimulation (rTMS) at 10 Hz over the left prefrontal cortex has been repeatedly demonstrated, it is not clear that the optimal parameters for the treatment of depression have been adequately elucidated.

Objectives: We sought to assess the antidepressant effectiveness of high and low frequency at a higher intensity rTMS compared to sham in patients with moderately treatment resistant depression.

Method: The authors conducted a three-week, double-blind, randomized, sham-controlled study of 24 acutely depressed patients given either active 20 Hz (n = 8) or 1 Hz (n = 8) rTMS (at 110% of motor threshold [MT]) or sham treatments (n = 8) over the left prefrontal cortex.

Potential of pretreatment neural activity in the visual cortex during emotional processing to predict treatment response to scopolamine in major depressive disorder.

Context: The need for improved treatment options for patients with major depressive disorder (MDD) is critical. Faster-acting antidepressants and biomarkers that predict clinical response will facilitate treatment. Scopolamine produces rapid antidepressant effects and thus offers the opportunity to characterize potential biomarkers of treatment response within short periods.

Baseline mood-state measures as predictors of antidepressant response to scopolamine.

Identifying predictors of antidepressant response will facilitate the successful treatment of patients suffering from depression. Scopolamine produces robust antidepressant responses in unipolar and bipolar depression. Here we evaluate the potential for baseline self-ratings to predict treatment response to scopolamine.

Interregional cerebral metabolic associativity during a continuous performance task (Part I): healthy adults.

One emerging hypothesis regarding psychiatric illnesses is that they arise from the dysregulation of normal circuits or neuroanatomical patterns. In order to study mood disorders within this framework, we explored normal metabolic associativity patterns in healthy volunteers as a prelude to examining the same relationships in affectively ill patients (Part II). We applied correlational analyses to regional brain activity as measured with FDG-PET during an auditory continuous performance task (CPT) in 66 healthy volunteers.

Preliminary findings of uncoupling of flow and metabolism in unipolar compared with bipolar affective illness and normal controls.

Cerebral metabolism (CMR for glucose or oxygen) and blood flow (CBF) have been reported to be closely correlated in healthy controls. Altered relationships between CMR and CBF have been reported in some brain disease states, but not others. This study examined relationships between global and regional CMRglu vs.

Is there progression from irritability/dyscontrol to major depressive and manic symptoms? A retrospective community survey of parents of bipolar children.

Background: Although previous studies have discussed age-related changes in the presentation of early onset bipolar illness, the developmental progression of early symptoms remains unclear. The current study sought to trace parents' retrospective report of yearly occurrence of symptoms in a sample of children with and without a diagnosis of bipolar disorder in the community.

Methods: Parents retrospectively rated the occurrence of 37 activated and withdrawn symptoms causing dysfunction for each year of their child's life (mean age 12.

Intensity-dependent regional cerebral blood flow during 1-Hz repetitive transcranial magnetic stimulation (rTMS) in healthy volunteers studied with H215O positron emission tomography: II. Effects of prefrontal cortex rTMS.

Background: The changes in brain activity produced by repetitive transcranial magnetic stimulation (rTMS) of the prefrontal cortex (PFC) remain unclear. We examined intensity-related changes in brain activity with positron emission tomography (PET) in normal volunteers during rTMS delivered to the left PFC.

Methods: In 10 healthy volunteers, we delivered 1-Hz rTMS at randomized intensities over left PFC with a figure-eight coil.

Intensity-dependent regional cerebral blood flow during 1-Hz repetitive transcranial magnetic stimulation (rTMS) in healthy volunteers studied with H215O positron emission tomography: I. Effects of primary motor cortex rTMS.

Background: Repetitive transcranial magnetic stimulation (rTMS) affects the excitability of the motor cortex and is thought to influence activity in other brain areas as well. We combined the administration of varying intensities of 1-Hz rTMS of the motor cortex with simultaneous positron emission tomography (PET) to delineate local and distant effects on brain activity.

Methods: Ten healthy subjects received 1-Hz rTMS to the optimal position over motor cortex (M1) for producing a twitch in the right hand at 80, 90, 100, 110, and 120% of the twitch threshold, while regional cerebral blood flow (rCBF) was measured using H(2)(15)O and PET.

Neurobiology of bipolar illness: implications for future study and therapeutics.

Many findings implicating prefrontal cortical and limbic areas of the brain and endocrine systems in the neuropathology and pathophysiology of bipolar illness have greatly increased our understanding of the neurobiology of the illness. New imaging techniques such as PET, MRI, SPECT, and MRS have detailed more evidence of specific regional alterations in the brains of bipolar patients than was thought possible just 20 years ago. These methods are beginning to be used to help predict response to treatment.

Clinical predictors of response to lamotrigine and gabapentin monotherapy in refractory affective disorders.

Background: The objective of the current study was to examine possible clinical predictors of positive response to lamotrigine or gabapentin monotherapy in treatment-refractory affectively ill patients.

Methods: Forty-five patients with treatment refractory bipolar (n = 35) or unipolar (n = 10) affective disorder participated in a clinical study evaluating six weeks of treatment with lamotrigine, gabapentin, or placebo monotherapy given in a double-blind, randomized fashion with two subsequent cross-overs to the other agents. Patients received daily mood ratings and weekly cross-sectional scales.