Imaging cortical electrical stimulation in vivo: fast intrinsic optical signal versus voltage-sensitive dyes.
We applied high-temporal-resolution optical imaging utilizing both the fast intrinsic optical signal (fIOS) and voltage-sensitive dyes (VSDs) to observe the spatiotemporal characteristics of rat somatosensory cortex during electrical stimulation. We find that changes in both the fIOS and VSD signals occur rapidly (<30 ms) after the stimulus is applied, suggesting that both membrane depolarization and transmembrane ion movement occur shortly after the stimulus, preceding the more gradual physiological changes in oxygen consumption revealed by the slower component of the intrinsic optical signal. We find that the VSD signal spreads through a much larger area of cortex than the fIOS.
Tsytsarev
Vassiliy
V
Department of Physics and Astronomy and Center for Neurodynamics, University of Missouri at St. Louis, One University Boulevard, St. Louis, Missouri 63121, USA. tsytsarev@umsl.edu
Premachandra
Kaushalya
K
Takeshita
Daisuke
D
Bahar
Sonya
S
D000818:Animals; D002540:Cerebral Cortex / Q000166:cytology / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D055095:Optics and Photonics / Q000295:instrumentation*; D051381:Rats; D017207:Rats, Sprague-Dawley