Novel Form of Spreading Acidification and Depression in the Cerebellar Cortex Demonstrated by Neutral Red Optical Imaging

• Published in: Journal of neurophysiology Vol. 81; no. 4; pp. 1992 - 1998
• Main Authors: Chen, G, Hanson, C. L, Dunbar, R. L, Ebner, T. J
• Format: Journal Article
• Language: English
• Published: United States Am Phys Soc 01-04-1999
• Subjects: Acids - metabolism; Action Potentials - drug effects; Action Potentials - physiology; Animals; Cerebellar Cortex - chemistry; Cerebellar Cortex - physiology; Coloring Agents; Cortical Spreading Depression - physiology; Electric Stimulation; Female; Male; Neutral Red; Optics and Photonics; Potassium Chloride - pharmacology; Rats; Rats, Sprague-Dawley
• ISSN: 0022-3077; 1522-1598
• DOI: 10.1152/jn.1999.81.4.1992

Departments of   1 Neuroscience and
  2 Neurosurgery, and
  3 Graduate Program in Neuroscience, University of
Minnesota, Minneapolis, Minnesota 55455
Chen, G.,
C. L. Hanson,
R. L. Dunbar, and
T. J. Ebner.
Novel form of spreading acidification and depression in the cerebellar
cortex demonstrated by neutral red optical imaging. A novel
form of spreading acidification and depression in the rat cerebellar
cortex was imaged in vivo using the pH-sensitive dye, Neutral red.
Surface stimulation evoked an initial beam of increased fluorescence
(i.e., decreased pH) that spread rostrally and caudally across the
folium and into neighboring folia. A transient but marked suppression
in the excitability of the parallel fiber-Purkinje cell circuitry
accompanied the spread. Characteristics differentiating this phenomenon
from the spreading depression of Leao include: high speed of
propagation on the surface (average of 450 µm/s), stable
extracellular DC potential, no change in blood vessel diameter, and
repeatability at short intervals. This propagating acidification constitutes a previously unknown class of neuronal processing in the
cerebellar cortex.