Luis M. Botana

Characterization of the Na+/H+ antiporter in cells of the mussel Mytilus galloprovincialis

Abstract 1. 1. The activity of the Na+/H+ antiporter in mussel mantle cells was studied by measuring the rate of intracellular pH (pHi) recovery in acid-loaded cells. Salts of propionic acid were used for acid-loading, and the fluorescent dye 2,7(carboxyethyl)-5(6)-carboxyfluorescein (BCECF) was chosen to monitor pHi changes. 2. 2. The velocity constant for the pHi recovery was 0.4406 ± 0.0059 pH U/min and showed no significant change when activating the Na+/H+ antiport with any of the several Na+ propionate concentrations. 3. 3. The depletion of Na+ in the extracellular fluid resulted in no pHi recovery after the acid loading (the Km values for Na+ was 84.24 mM). 4. 4. Protein kinase C activators had no effect in the velocity of pHi recovery.

Transcriptomic Profiling of Mice Primary Cortical Neurons in Response toMedium Change

The first in vitro system for the culture of primary neurons was developed in 1977. Since then, the culture systems nfor hippocampal and cortical neurons, as well as neuron cell lines, have improved dramatically. Primary neuronal ncultures provide a defined environment where neurons can be studied in isolation from other cell types and are a npowerful tool for studying cellular and molecular mechanisms of neuronal development, aging, and death. However, nthe changes that occur in neurons during culture in relation to cell differentiation and medium composition have not nbeen thoroughly characterized. To study the effect of medium change in primary neurons in culture, we performed a ntranscriptomic analysis using whole mouse genome microarrays, for neurons between 7 and 10 days in vitro after nmedium change. We show that even though neurons in culture present an expression profile pointing to differentiation nwith time in culture, medium change induces a transient and partial de-differentiation.