Steven K Brannan

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OBJECTIVE Theories of human behavior from Plato to Freud have repeatedly emphasized links between emotion and reason, a relationship now commonly attributed to pathways connecting phylogenetically "old" and "new" brain regions. Expanding on this theory, this study examined functional interactions between specific limbic and neocortical regions accompanying(More)
The relationship between pretreatment regional cerebral glucose metabolism and eventual antidepressant drug response was measured using positron emission tomography (PET) in hospitalized patients with unipolar depression. Rostral anterior cingulate metabolism uniquely differentiated eventual treatment responders from non-responders. Hypometabolism(More)
BACKGROUND Treatment of major depression with antidepressants is generally associated with a delay in onset of clinical response. Functional brain correlates of this phenomenon have not been previously characterized. METHODS Time course of changes in brain glucose metabolism were measured using positron emission tomography in hospitalized unipolar(More)
BACKGROUND Affective disorders are associated with comorbidity of depression and anxiety symptoms. Positron emission tomography resting-state studies in affective disorders have generally failed to isolate specific symptom effects. Emotion provocation studies in healthy volunteers have produced variable results, due to differences in experimental paradigm(More)
OBJECTIVE Administration of placebo can result in a clinical response indistinguishable from that seen with active antidepressant treatment. Functional brain correlates of this phenomenon have not been fully characterized. METHOD Changes in brain glucose metabolism were measured by using positron emission tomography in hospitalized men with unipolar(More)
Little is known about the physiological mechanisms subserving the experience of air hunger and the affective control of breathing in humans. Acute hunger for air after inhalation of CO(2) was studied in nine healthy volunteers with positron emission tomography. Subjective breathlessness was manipulated while end-tidal CO(2-) was held constant. Subjects(More)
There are defined medullary, mesencephalic, hypothalamic, and thalamic functions in regulation of respiration, but knowledge of cortical control and the elements subserving the consciousness of breathlessness and air hunger is limited. In nine young adults, air hunger was produced acutely by CO(2) inhalation. Comparisons were made with inhalation of a(More)
Recent neuroimaging and neurological data implicate cerebellum in nonmotor sensory, cognitive, vegetative, and affective functions. The present study assessed cerebellar responses when the urge to breathe is stimulated by inhaled CO(2). Ventilation changes follow arterial blood partial pressure CO(2) changes sensed by the medullary ventral respiratory group(More)
Post-traumatic stress disorder (PTSD) is a common and increasingly diagnosed mental illness. Recent pharmacotherapeutic research on treatments for this condition has focused on antidepressant drugs with serotonergic actions. However, the presence of intrusive, psychotic-like symptoms in a substantial portion of PTSD patients raises the possibility that(More)
Behavioral deficits following inescapable stress (learned helplessness) may serve as an animal model of depression. Previous studies using foot-shock stress to induce learned helplessness and a bar-press test for the stress-induced behavioral deficit have found increased beta-adrenergic receptor density in the hippocampus of learned helpless rats. We(More)