Effect of Na+ and Cl-on the velocity of propagation of the spreading depression in chick retina

RESUMEN

The chick retina in vitro preparation was used to quantify the effect of Na+ and Cl- on the velocity of propagation of spreading depression (SD). The progressive reduction of chloride concentration in the superfusing Ringer solution, solution, either by partial removal of NaCl or by its partial substitution with isethionate, caused a logarithmic increase in the velocity of propagation of SD. Substituting Tris for Na+ had no appreciable effect on propagation velocity, suggesting that the propagation of the reaction is not necessarily dependent con Na+. Howeverm choline did not substitute for Na+ because it decreased propagation velocity and, at higher concentration, even blocked the spread of the reaction