 |
 Previous Article | Next Article 
Journal of Neuroscience, Vol 10, 3494-3506, Copyright © 1990 by Society for Neuroscience
An in vitro analysis of sound localization mechanisms in the gerbil lateral superior olive
DH Sanes
Department of Otolaryngology, New York University Medical Center, New York 10016.
One way in which animals localize sounds along the horizon is by detecting
the level differences at the 2 ears. Neurons in the lateral superior olive
(LSO) encode this cue by integrating the synaptic drive from ipsilateral
excitatory and contralateral inhibitory connections. This synaptic
integration was analyzed in 400-500-microns brain slices through the gerbil
superior olive. Intracellular recordings from LSO neurons were obtained
during the application of independent or conjoint electrical stimuli to the
excitatory afferent and inhibitory afferent pathways. Stimulation of
ascending fibers from the ipsilateral cochlear nucleus reliably evoked
EPSPs and action potentials. Stimulation of the medial nucleus of the
trapezoid body (MNTB) consistently evoked IPSPs. The evoked postsynaptic
potentials differed in that IPSPs were 2 times the duration of EPSPs. An
electrophysiological estimate of convergence indicated approximately 10
excitatory and 8 inhibitory afferents per LSO neuron. MNTB stimulation
suppressed synaptically evoked action potentials. When stimulus amplitude
was increased to the excitatory pathway, it was generally found that a
greater MNTB stimulus was necessary to suppress the action potential. A
similar commensurate rise in ipsilateral and contralateral acoustic
stimulation was also found to be necessary to give the same criterion
response. These results confirm that the LSO can integrate evoked action
potentials and IPSPs to encode interaural level. Increasing stimulus
voltage was found to decrease both action potential and IPSP latency,
suggesting that intensity information may be encoded with temporal cues in
the nervous system. It was also found that an evoked burst of action
potentials could be inhibited in such a way as to yield intermediate
discharge rates, dependent on contralateral stimulus level. Taken together,
these results suggest that certain properties related to level-difference
coding may be available for intracellular analysis using the brain- slice
preparation. Several temporal characteristics of the synaptic potentials,
including latency and duration, may play a critical role in this simple
computation.
This article has been cited by other articles:
|
|
|
|
 
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]
|
|
|
|
|
|
|
Y. Zhou, L. H. Carney, and H. S. Colburn
A Model for Interaural Time Difference Sensitivity in the Medial Superior Olive: Interaction of Excitatory and Inhibitory Synaptic Inputs, Channel Dynamics, and Cellular Morphology
J. Neurosci.,
March 23, 2005;
25(12):
3046 - 3058.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. J. Park, A. Klug, M. Holinstat, and B. Grothe
Interaural Level Difference Processing in the Lateral Superior Olive and the Inferior Colliculus
J Neurophysiol,
July 1, 2004;
92(1):
289 - 301.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. L. Sutter and W. C. Loftus
Excitatory and Inhibitory Intensity Tuning in Auditory Cortex: Evidence for Multiple Inhibitory Mechanisms
J Neurophysiol,
October 1, 2003;
90(4):
2629 - 2647.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. H. Chang, V. C. Kotak, and D. H. Sanes
Long-Term Depression of Synaptic Inhibition Is Expressed Postsynaptically in the Developing Auditory System
J Neurophysiol,
September 1, 2003;
90(3):
1479 - 1488.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. J. Tollin
The Lateral Superior Olive: A Functional Role in Sound Source Localization
Neuroscientist,
April 1, 2003;
9(2):
127 - 143.
[Abstract]
[PDF]
|
|
|
|
|
|
|
D. J. Tollin and T. C. T. Yin
The Coding of Spatial Location by Single Units in the Lateral Superior Olive of the Cat. I. Spatial Receptive Fields in Azimuth
J. Neurosci.,
February 15, 2002;
22(4):
1454 - 1467.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. J. Tollin and T. C. T. Yin
The Coding of Spatial Location by Single Units in the Lateral Superior Olive of the Cat. II. The Determinants of Spatial Receptive Fields in Azimuth
J. Neurosci.,
February 15, 2002;
22(4):
1468 - 1479.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D.R.F. Irvine, V. N. Park, and L. McCormick
Mechanisms Underlying the Sensitivity of Neurons in the Lateral Superior Olive to Interaural Intensity Differences
J Neurophysiol,
December 1, 2001;
86(6):
2647 - 2666.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
H. Taschenberger and H. von Gersdorff
Fine-Tuning an Auditory Synapse for Speed and Fidelity: Developmental Changes in Presynaptic Waveform, EPSC Kinetics, and Synaptic Plasticity
J. Neurosci.,
December 15, 2000;
20(24):
9162 - 9173.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
U. Koch and B. Grothe
Interdependence of Spatial and Temporal Coding in the Auditory Midbrain
J Neurophysiol,
April 1, 2000;
83(4):
2300 - 2314.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. B. Kelly and S. A. Kidd
NMDA and AMPA Receptors in the Dorsal Nucleus of the Lateral Lemniscus Shape Binaural Responses in Rat Inferior Colliculus
J Neurophysiol,
March 1, 2000;
83(3):
1403 - 1414.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. K. Fitzgerald and D. H. Sanes
Serotonergic Modulation of Synapses in the Developing Gerbil Lateral Superior Olive
J Neurophysiol,
June 1, 1999;
81(6):
2743 - 2752.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
V. C. Kotak, S. Korada, I. R. Schwartz, and D. H. Sanes
A Developmental Shift from GABAergic to Glycinergic Transmission in the Central Auditory System
J. Neurosci.,
June 15, 1998;
18(12):
4646 - 4655.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Zacksenhouse, D. H. Johnson, J. Williams, and C. Tsuchitani
Single-Neuron Modeling of LSO Unit Responses
J Neurophysiol,
June 1, 1998;
79(6):
3098 - 3110.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. H. Smith, P. X. Joris, and T. C. T. Yin
Anatomy and Physiology of Principal Cells of the Medial Nucleus of the Trapezoid Body (MNTB) of the Cat
J Neurophysiol,
June 1, 1998;
79(6):
3127 - 3142.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. J. Park
IID Sensitivity Differs Between Two Principal Centers in the Interaural Intensity Difference Pathway: the LSO and the IC
J Neurophysiol,
May 1, 1998;
79(5):
2416 - 2431.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. P. Harty and P. B. Manis
Kinetic Analysis of Glycine Receptor Currents in Ventral Cochlear Nucleus
J Neurophysiol,
April 1, 1998;
79(4):
1891 - 1901.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. H. Sanes, B. J. Malone, and M. N. Semple
Role of Synaptic Inhibition in Processing of Dynamic Binaural Level Stimuli
J. Neurosci.,
January 15, 1998;
18(2):
794 - 803.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. X. Joris and T. C. T. Yin
Envelope Coding in the Lateral Superior Olive. III. Comparison With Afferent Pathways
J Neurophysiol,
January 1, 1998;
79(1):
253 - 269.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. Batra, S. Kuwada, and D. C. Fitzpatrick
Sensitivity to Interaural Temporal Disparities of Low- and High-Frequency Neurons in the Superior Olivary Complex. I. Heterogeneity of Responses
J Neurophysiol,
September 1, 1997;
78(3):
1222 - 1236.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. Batra, S. Kuwada, and D. C. Fitzpatrick
Sensitivity to Interaural Temporal Disparities of Low- and High-Frequency Neurons in the Superior Olivary Complex. II. Coincidence Detection
J Neurophysiol,
September 1, 1997;
78(3):
1237 - 1247.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. J. Park, P. Monsivais, and G. D. Pollak
Processing of Interaural Intensity Differences in the LSO: Role of Interaural Threshold Differences
J Neurophysiol,
June 1, 1997;
77(6):
2863 - 2878.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. J. Park, B. Grothe, G. D. Pollak, G. Schuller, and U. Koch
Neural Delays Shape Selectivity to Interaural Intensity Differences in the Lateral Superior Olive
J. Neurosci.,
October 15, 1996;
16(20):
6554 - 6566.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
