Publications by authors named "Samuel Burke"

In Parkinson's disease (PD), motor dysfunctions only become apparent after extensive loss of DA innervation. This resilience has been hypothesized to be due to the ability of many motor behaviors to be sustained through a diffuse basal tone of DA; but experimental evidence for this is limited. Here we show that conditional deletion of the calcium sensor synaptotagmin-1 (Syt1) in DA neurons (Syt1 cKO mice) abrogates most activity-dependent axonal DA release in the striatum and mesencephalon, leaving somatodendritic (STD) DA release intact.

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Initiating drug use during adolescence increases the risk of developing addiction or other psychopathologies later in life, with long-term outcomes varying according to sex and exact timing of use. The cellular and molecular underpinnings explaining this differential sensitivity to detrimental drug effects remain unexplained. The Netrin-1/DCC guidance cue system segregates cortical and limbic dopamine pathways in adolescence.

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Aging is the primary risk factor for most neurodegenerative diseases, including Alzheimer's disease. Major hallmarks of brain aging include neuroinflammation/immune activation and reduced neuronal health/function. These processes contribute to cognitive dysfunction (a key risk factor for Alzheimer's disease), but their upstream causes are incompletely understood.

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Several populations of neurons are purported to degenerate in Parkinson's disease (PD). One current hypothesis suggests that vulnerable neurons in PD share common characteristics including projecting to voluminous territories and having extremely long and branched axonal domains with large numbers of neurotransmitter release sites. In this study, we used a mouse culture system to compare the axonal domain of neuronal populations suspected to be vulnerable in PD to that of neuronal populations considered at a lesser risk.

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Background And Objective: To determine macular retinal sublayer thickness changes in G11778A Leber hereditary optic neuropathy (LHON).

Patients And Methods: The authors performed a cross-sectional study by segmenting spectral-domain Cirrus OCT (Carl Zeiss Meditec, Dublin, CA) 512 × 128 macular cube scans from a prospective, observational study of G11778A LHON. The thickness of the retinal sublayers of LHON affected subjects and asymptomatic carriers were compared to those of a normal group.

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