Donald A. Fox

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Calcium overload is suggested to play a fundamental role in the process of rod apoptosis in chemical-induced and inherited retinal degenerations. However, this hypothesis has not been tested directly. We developed an in vitro model utilizing isolated rat retinas to determine the mechanisms underlying Ca(2+)- and/or Pb(2+)-induced retinal degeneration.(More)
PURPOSE Comparative studies of structure related to function offer a promising means of understanding the significance of differences in cytoarchitecture. Mitochondrial crista structure is linked tightly to mitochondrial function. Non-foveal cone photoreceptors of primates contain considerably more inner segment mitochondria and have higher oxidative enzyme(More)
Photoreceptor apoptosis and resultant visual deficits occur in humans and animals with inherited and disease-, injury-, and chemical-induced retinal degeneration. A clinically relevant mouse model of progressive rod photoreceptor-selective apoptosis was produced by low-level developmental lead exposure and studied in combination with transgenic mice(More)
Biochemical, physiological and histological data have established that 55-65% of retinal mitochondria are located in the photoreceptor inner segments and suggested that photoreceptors have at least a two-fold greater oxygen consumption (QO2) than the remaining inner retina. QO2 in isolated whole rat retina (QWR), outer retina (QOR) and inner retina (QIR)(More)
The effects of lead exposure on cognitive function have been intensively studied during the past decade, but relatively little effort has been made to understand the impact on sensory function. Subtle impairments of visual and/or auditory processing, however, could have profound effects on learning. The objectives of this paper are to review what is known(More)
Long-term visual system deficits occur in man and animals following developmental and occupational lead exposure. Recent experimental data suggests that the adult brain is not altered following lead exposure. Therefore, the aim of these studies was to use the retina as a CNS model to examine and compare the morphological, biochemical and(More)
Our previous work suggests that cone photoreceptor inner segment (CIS) mitochondria demand and produce more ATP than rods. The CISs utilize two complimentary strategies to increase ATP production: increase the absolute number of mitochondria and their cristae surface membrane area. In this treatise, we ask: How are crista junctions formed and regulated?(More)
In vitro studies have demonstrated that lead selectively and reversibly depresses the rod photoreceptor component of the electroretinogram (ERG). To determine if low-level lead exposure during early postnatal development produced long-term selective rod deficits, we examined rod and cone ERG functions and cyclic GMP and cyclic AMP metabolism in adult(More)
PURPOSE In conventional neurons, Ca2+ enters presynaptic terminals during an action potential and its increased local concentration triggers transient exocytosis. In contrast, vertebrate photoreceptors are nonspiking neurons that maintain sustained depolarization and neurotransmitter release from ribbon synapses in darkness and produce light-dependent(More)
Autoantibodies against recoverin are found in the sera of patients with cancer-associated retinopathy (CAR) syndrome. In these studies we examined the effect of anti-recoverin antibodies from the sera of patients with CAR and rat monoclonal antibody on the retinas of Lewis rats. Anti-recoverin autoanti-bodies penetrated into the photoreceptor and bipolar(More)