Evaluation of mechanisms involved in regulation of intrinsic excitability by extracellular calcium in CA1 pyramidal neurons of rat.

It is well recognized that changes in the extracellular concentration of calcium ions influence the excitability of neurons, yet what mechanism(s) mediate these effects is still a matter of debate. Using patch-clamp recordings from rat hippocampal CA1 pyramidal neurons, we examined the contribution of G-proteins and intracellular calcium-dependent signaling mechanisms to changes in intrinsic excitability evoked by altering the extracellular calcium concentration from physiological (1.2 mM) to a commonly used experimental (2 mM) level.

A Novel Primary Porcine Retinal Pigment Epithelium Cell Model with Preserved Properties.

Purpose: To establish an ethical, reliable, and expandable retinal pigment epithelial (RPE) cell model with maintained RPE properties compatible with multifarious assays.

Methods: RPE cells from abattoir-obtained porcine eyes were cultured under various conditions. Morphology, RPE cell-specific protein markers (RPE-65, CRALBP), and the tight junction marker ZO-1 were analyzed by phase-contrast microscopy, immunocytochemistry, and western blot, and transepithelial electrical resistance (TEER) was determined to assess barrier function.