OBJECTIVES The goal of this study was to describe the mapping and ablation of polymorphic ventricular tachycardia (VT) after myocardial infarction (MI). BACKGROUND The initiating mechanisms of polymorphic VT after MI have not been reported. METHODS Five patients (four males; age 61 +/- 7 years) with recurrent episodes of polymorphic VT after anterior MI (left ventricular ejection fraction 3...

To identify the anatomical basis for cardiac electrical signal conduction, particularly seeking the intramural terminals of conduction pathway within the ventricles, sheep hearts were examined compared with human hearts utilizing the characteristic morphology of Purkinje cells as a histological marker. In 15 sheep and five human autopsies of noncardiac death, prevalence of Purkinje or Purkinje-...

The effects of target loss on adult axonal arbors were investigated by comparing the morphological changes of adult climbing fibers in several mutant mouse strains where Purkinje cells slowly degenerate (namely, Lurcher, nervous, Purkinje cell degeneration, and tambaleante), with those occurring after a fast Purkinje cell death induced by mechanical lesions of the adult mouse cerebellum. In eac...

Pathways regulating neuronal vulnerability are poorly understood, yet are central to identifying therapeutic targets for degenerative neurological diseases. Here, we characterize mechanisms underlying neurodegeneration in Niemann-Pick type C (NPC) disease, a lysosomal storage disorder characterized by impaired cholesterol trafficking. To date, the relative contributions of neuronal and glial de...

Brief strong depolarization of cerebellar Purkinje cells produces a slow inward cation current. This current, called depolarization-induced slow current (DISC), is triggered by Ca influx in the Purkinje cell and is attenuated by a blocker of vesicular fusion. Previous work in other brain regions, such as the substantia nigra and ventral tegmental area, has shown that dopamine can be released fr...

In immunohistochemical reactions against glutamic acid decarboxylase (GAD), gamma-aminobutyric acid (GABA) and glycine (Gly), neurons in the mouse cerebellum showed the following reactivities: (1) the dendrites and cell bodies of the Purkinje cells were only GAD-positive, but their axonal terminals were GABA- and GAD-positive; (2) in both stellate and basket cells, the cell bodies and terminals...

Neurosteroids are synthesized de novo from cholesterol in the brain. To understand neurosteroid action in the brain, data on the regio- and temporal-specific synthesis of neurosteroids are needed. Recently, we identified the Purkinje cell as an active neurosteroidogenic cell. In rodents, this neuron actively produces several neurosteroids including estradiol during neonatal life, when cerebella...

The rhythmic heart beat is coordinated by electrical impulses transmitted from Purkinje fibers of the cardiac conduction system. During embryogenesis, the impulse-conducting cells differentiate from cardiac myocytes in direct association with the developing endocardium and coronary arteries, but not with the venous system. This conversion of myocytes into Purkinje fibers requires a paracrine in...

The human cerebellum is associated with smooth control of movements and memory. As age advances deterioration is noticed in the cerebellum. The Purkinje cells act as the pivot in the neuronal circuitry of the cerebellum, which initiates and maintains complex, but smooth pursuit movements and it can be identified as one of the factors which cause the decline in movement and memory in humans as a...