 |
|||||
|
|||||
|
|||||
|
|||||
|
|||||
Previous Article | Next Article
The Journal of Neuroscience, April 15, 1999, 19(8):2897-2905
Role of Intrinsic Conductances Underlying Responses to Transients in Octopus Cells of the Cochlear Nucleus
Nace L. Golding , Michael J. Ferragamo, and Donata Oertel Department of Physiology, University of Wisconsin, Madison, Wisconsin 53706
Recognition of acoustic patterns in natural sounds depends on the transmission of temporal information. Octopus cells of the mammalian ventral cochlear nucleus form a pathway that encodes the timing of firing of groups of auditory nerve fibers with exceptional precision. Whole-cell patch recordings from octopus cells were used to examine how the brevity and precision of firing are shaped by intrinsic conductances. Octopus cells responded to steps of current with small, rapid voltage changes. Input resistances and membrane time constants averaged 2.4 M
and 210 µsec, respectively (n = 15). As a result of the low input resistances of octopus cells, action potential initiation required currents of at least 2 nA for their generation and never occurred repetitively. Backpropagated action potentials recorded at the soma were small (10-30 mV), brief (0.24-0.54 msec), and tetrodotoxin-sensitive. The low input resistance arose in part from an inwardly rectifying mixed cationic conductance blocked by cesium and potassium conductances blocked by 4-aminopyridine (4-AP). Conductances blocked by 4-AP also contributed to the repolarization of the action potentials and suppressed the generation of calcium spikes.
In the face of the high membrane conductance of octopus cells, sodium and calcium conductances amplified depolarizations produced by intracellular current injection over a time course similar to that of EPSPs. We suggest that this transient amplification works in concert with the shunting influence of potassium and mixed cationic conductances to enhance the encoding of the onset of synchronous auditory nerve fiber activity.
Key words: cochlear nucleus; auditory pathways; octopus cells; potassium channels; inward rectifier; Ih; 4-aminopyridine; cesium
Copyright © 1999 Society for Neuroscience 0270-6474/99/1982897-09$05.00/0
This article has been cited by other articles:
T. Blackmer, S. P. Kuo, K. J. Bender, P. F. Apostolides, and L. O. Trussell
Dendritic Calcium Channels and Their Activation by Synaptic Signals in Auditory Coincidence Detector Neurons
J Neurophysiol, August 1, 2009; 102(2): 1218 - 1226.
[Abstract] [Full Text] [PDF]
H. Kuba and H. Ohmori
Roles of axonal sodium channels in precise auditory time coding at nucleus magnocellularis of the chick
J. Physiol., January 1, 2009; 587(1): 87 - 100.
[Abstract] [Full Text] [PDF]
Z. Rusznak, G. Bakondi, K. Pocsai, A. Por, L. Kosztka, B. Pal, D. Nagy, and G. Szucs
Voltage-gated Potassium Channel (Kv) Subunits Expressed in the Rat Cochlear Nucleus
J. Histochem. Cytochem., May 1, 2008; 56(5): 443 - 465.
[Abstract] [Full Text] [PDF]
S. Yang and A. S. Feng
Heterogeneous Biophysical Properties of Frog Dorsal Medullary Nucleus (Cochlear Nucleus) Neurons
J Neurophysiol, October 1, 2007; 98(4): 1953 - 1964.
[Abstract] [Full Text] [PDF]
X.-J. Cao, S. Shatadal, and D. Oertel
Voltage-Sensitive Conductances of Bushy Cells of the Mammalian Ventral Cochlear Nucleus
J Neurophysiol, June 1, 2007; 97(6): 3961 - 3975.
[Abstract] [Full Text] [PDF]
J. X. Gittelman and B. L Tempel
Kv1.1-Containing Channels Are Critical for Temporal Precision During Spike Initiation
J Neurophysiol, September 1, 2006; 96(3): 1203 - 1214.
[Abstract] [Full Text] [PDF]
J. Nogueira, M. E. Castello, and A. A. Caputi
The role of single spiking spherical neurons in a fast sensory pathway
J. Exp. Biol., March 15, 2006; 209(6): 1122 - 1134.
[Abstract] [Full Text] [PDF]
A. K Magnusson, C. Kapfer, B. Grothe, and U. Koch
Maturation of glycinergic inhibition in the gerbil medial superior olive after hearing onset
J. Physiol., October 15, 2005; 568(2): 497 - 512.
[Abstract] [Full Text] [PDF]
X.-J. Cao and D. Oertel
Temperature Affects Voltage-Sensitive Conductances Differentially in Octopus Cells of the Mammalian Cochlear Nucleus
J Neurophysiol, July 1, 2005; 94(1): 821 - 832.
[Abstract] [Full Text] [PDF]
H. Kuba, R. Yamada, I. Fukui, and H. Ohmori
Tonotopic Specialization of Auditory Coincidence Detection in Nucleus Laminaris of the Chick
J. Neurosci., February 23, 2005; 25(8): 1924 - 1934.
[Abstract] [Full Text] [PDF]
E. S. Fortune and G. J. Rose
Voltage-Gated Na+ Channels Enhance the Temporal Filtering Properties of Electrosensory Neurons in the Torus
J Neurophysiol, August 1, 2003; 90(2): 924 - 929.
[Abstract] [Full Text] [PDF]
J. S. Rothman and P. B. Manis
Differential Expression of Three Distinct Potassium Currents in the Ventral Cochlear Nucleus
J Neurophysiol, June 1, 2003; 89(6): 3070 - 3082.
[Abstract] [Full Text] [PDF]
D. Soares, R. A. Chitwood, R. L. Hyson, and C. E. Carr
Intrinsic Neuronal Properties of the Chick Nucleus Angularis
J Neurophysiol, July 1, 2002; 88(1): 152 - 162.
[Abstract] [Full Text] [PDF]
O. Behrend, A. Brand, C. Kapfer, and B. Grothe
Auditory Response Properties in the Superior Paraolivary Nucleus of the Gerbil
J Neurophysiol, June 1, 2002; 87(6): 2915 - 2928.
[Abstract] [Full Text] [PDF]
M. J. Ferragamo and D. Oertel
Octopus Cells of the Mammalian Ventral Cochlear Nucleus Sense the Rate of Depolarization
J Neurophysiol, May 1, 2002; 87(5): 2262 - 2270.
[Abstract] [Full Text] [PDF]
R. Bal and D. Oertel
Potassium Currents in Octopus Cells of the Mammalian Cochlear Nucleus
J Neurophysiol, November 1, 2001; 86(5): 2299 - 2311.
[Abstract] [Full Text] [PDF]
K. Fujino and D. Oertel
Cholinergic Modulation of Stellate Cells in the Mammalian Ventral Cochlear Nucleus
J. Neurosci., September 15, 2001; 21(18): 7372 - 7383.
[Abstract] [Full Text] [PDF]
S. M. Gardner, L. O. Trussell, and D. Oertel
Correlation of AMPA Receptor Subunit Composition with Synaptic Input in the Mammalian Cochlear Nuclei
J. Neurosci., September 15, 2001; 21(18): 7428 - 7437.
[Abstract] [Full Text] [PDF]
M. F Cuttle, Z. Rusznak, A. Y C Wong, S. Owens, and I. D Forsythe
Modulation of a presynaptic hyperpolarization-activated cationic current (Ih) at an excitatory synaptic terminal in the rat auditory brainstem
J. Physiol., August 1, 2001; 534(3): 733 - 744.
[Abstract] [Full Text] [PDF]
D. Oertel, R. Bal, S. M. Gardner, P. H. Smith, and P. X. Joris
Detection of synchrony in the activity of auditory nerve fibers by octopus cells of the mammalian cochlear nucleus
PNAS, October 24, 2000; 97(22): 11773 - 11779.
[Abstract] [Full Text] [PDF]
R. Bal and D. Oertel
Hyperpolarization-Activated, Mixed-Cation Current (Ih) in Octopus Cells of the Mammalian Cochlear Nucleus
J Neurophysiol, August 1, 2000; 84(2): 806 - 817.
[Abstract] [Full Text] [PDF]
Y. Cai, J. McGee, and E. J. Walsh
Contributions of Ion Conductances to the Onset Responses of Octopus Cells in the Ventral Cochlear Nucleus: Simulation Results
J Neurophysiol, January 1, 2000; 83(1): 301 - 314.
[Abstract] [Full Text] [PDF]
|
|
|
|
 |
|