Mechanisms and effects of transepithelial polarization in the isolated semicircular canal.
Previous studies have shown that galvanic stimulation of semicircular canal organs can modulate their afferent discharge. However, it has not been resolved whether this modulation derived from direct stimulation of hair cells, afferent nerve fibers, some combination of the two, or some as yet unknown path. This problem is addressed in the present study. Experiments were designed first to determine the gross current path necessary for the DC current to modulate afferent firing. These led to the conclusion that the current path had to flow between endolymph and perilymph across the neuroepithelium. Next, the various components in this established path were considered: the afferents, the hair cells, between the hair cells, or some combination of the three. These experiments led to the conclusion that the current pathway was across the hair cells causing transmitter release and thus affecting afferent activity.
Norris
C H
CH
Department of Otolaryngology-Head and Neck Surgery, Tulane University Medical School, New Orleans, LA 70112, USA.
Miller
A J
AJ
Perin
P
P
Holt
J C
JC
Guth
P S
PS
D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology; D001569:Benzodiazepines; D004558:Electric Stimulation; D004848:Epithelium / Q000502:physiology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006198:Hair Cells, Auditory / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D009412:Nerve Fibers / Q000187:drug effects / Q000502:physiology; D018377:Neurotransmitter Agents / Q000037:antagonists & inhibitors; D011189:Potassium Chloride; D011894:Rana pipiens; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors; D012665:Semicircular Canals / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*
D014151:Anti-Anxiety Agents; D018691:Excitatory Amino Acid Antagonists; D018377:Neurotransmitter Agents; D018091:Receptors, AMPA; C061950:GYKI 52466; D001569:Benzodiazepines; D011189:Potassium Chloride; D000584:Amiloride