Evaluation and Optimization of Methods for Generating High-Resolution Retinotopic Maps Using Visual Cortex Voltage-Sensitive Dye Imaging.

The localization and measurement of neuronal activity magnitude at high spatial and temporal resolution are essential for mapping and better understanding neuronal systems and mechanisms. One such example is the generation of retinotopic maps, which correlates localized retinal stimulation with the corresponding specific visual cortex responses. Here we evaluated and compared seven different methods for extracting and localizing cortical responses from voltage-sensitive dye imaging recordings, elicited by visual stimuli projected directly on the rat retina by a customized projection system.

High-resolution VSDI retinotopic mapping via a DLP-based projection system.

High-resolution recording of visual cortex activity is an important tool for vision research. Using a customized digital mirror device (DMD) - based system equipped with retinal imaging, we projected visual stimuli directly on the rat retina and recorded cortical responses by voltage-sensitive dye imaging. We obtained robust cortical responses and generated high-resolution retinotopic maps at an unprecedented retinal resolution of 4.

Endovascular Electrical Stimulation - A Novel Hemorrhage Control Technique.

Objective: In this study we present a novel approach for inducing vasoconstriction by pulsed electrical treatment delivered via endovascular electrodes, which can be used in cases where external access to the vessel is limited.

Methods: Using computer simulations, we optimized various geometries of endovascular electrodes to maximize the induced electric field on the arterial wall. Using the optimal configuration parameters, we investigated endovascular induced vasoconstriction in both the carotid and femoral sheep arteries.