JN AJP: Renal Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Neurophysiol 85: 84-88, 2001;
0022-3077/01 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (9)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Yoshida, N.
Right arrow Articles by Sewell, W. F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Yoshida, N.
Right arrow Articles by Sewell, W. F.

The Journal of Neurophysiology Vol. 85 No. 1 January 2001, pp. 84-88
Copyright ©2001 by the American Physiological Society

Fast, But Not Slow, Effects of Olivocochlear Activation Are Resistant to Apamin

Naohiro Yoshida,1,2,4 M. Charles Liberman,1,2,3 M. Christian Brown,1,2 and William F. Sewell1,2,3

 1Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary; and  2Department of Otology and Laryngology and  3Program in Neuroscience, Harvard Medical School, Boston, Massachusetts 02114; and  4Department of Otolaryngology, Tohoku University, School of Medicine, Sendai 980-8574, Japan

Yoshida, Naohiro, M. Charles Liberman, M. Christian Brown, and William F. Sewell. Fast, But Not Slow, Effects of Olivocochlear Activation Are Resistant to Apamin. J. Neurophysiol. 85: 84-88, 2001. Olivocochlear (OC) efferent suppression of auditory-nerve responses comprises a fast effect lasting tens of milliseconds and a slow effect building and decaying over tens of seconds. Both fast and slow effects are mediated by activation of the same alpha 9 nicotinic receptor. We have hypothesized that fast effects are generated at the OC synapse, but that slow effects reflect activation of calcium-activated potassium (KCa) channels by calcium release from the subsurface cisternae on the basolateral wall of the hair cells. We measured in vivo effects of apamin, a blocker of small-conductance (SK) KCa channels, and charybdotoxin, a blocker of large-conductance KCa channels, perfused through scala tympani, on fast and slow effects evoked by electrical stimulation of the OC bundle in anesthetized guinea pigs. Apamin selectively and reversibly reduced slow-effect amplitude without altering fast effects or baseline amplitude of the auditory-nerve response, but only when perfused at concentrations of 100 µM. In contrast, the effects of charybdotoxin were noted at 30 nM, but were not specific, reducing both afferent and efferent responses. The very high concentrations of apamin needed to block efferent effects contrasts with the high sensitivity of isolated hair cells to apamin's block of acetylcholine's effects. The results suggest that in vivo fast OC effects are dominated by a conductance that is not apamin sensitive.




This article has been cited by other articles:


Home page
 J. Neurophysiol.Home page
S. F. Maison, D. E. Vetter, and M. C. Liberman
A Novel Effect of Cochlear Efferents: In Vivo Response Enhancement Does Not Require {alpha}9 Cholinergic Receptors
J Neurophysiol, May 1, 2007; 97(5): 3269 - 3278.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
R. Dawkins, S. L. Keller, and W. F. Sewell
Pharmacology of Acetylcholine-Mediated Cell Signaling in the Lateral Line Organ Following Efferent Stimulation
J Neurophysiol, May 1, 2005; 93(5): 2541 - 2551.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
L. Nie, H. Song, M.-F. Chen, N. Chiamvimonvat, K. W. Beisel, E. N. Yamoah, and A. E. Vazquez
Cloning and Expression of a Small-Conductance Ca2+-Activated K+ Channel From the Mouse Cochlea: Coexpression with {alpha}9/{alpha}10 Acetylcholine Receptors
J Neurophysiol, April 1, 2004; 91(4): 1536 - 1544.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
L. J. Skinner, V. Enee, M. Beurg, H. H. Jung, A. F. Ryan, A. Hafidi, J.-M. Aran, and D. Dulon
Contribution of BK Ca2+-Activated K+ Channels to Auditory Neurotransmission in the Guinea Pig Cochlea
J Neurophysiol, July 1, 2003; 90(1): 320 - 332.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
N P Cooper and J J Guinan Jr
Separate mechanical processes underlie fast and slow effects of medial olivocochlear efferent activity
J. Physiol., April 1, 2003; 548(1): 307 - 312.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online