Abstract

A number of studies have utilized bright field illumination of neural tissue to image intrinsic absorbance changes associated with slow hemodynamic responses. These methods produce high-resolution but static spatial activation maps from the cortical surface. In order to capture dynamic spatio-temporal patterns, other investigators have employed voltage sensitive dyes. We imaged and investigated fast intrinsic optical responses to vagal nerve stimulation within the nucleus tractus solitarius (NTS) of the rat dorsal brainstem using a novel variable-focus imaging probe without dyes. Dark field illumination enhanced the contrast of light scattering changes, that track electrical dynamics of neuronal activation.

© 2000 Optical Society of America