 |
 Previous Article | Next Article 
The Journal of Neuroscience, July 1, 2001, 21(13):4830-4843
Reversible Inactivation of the Dorsal Nucleus of the Lateral
Lemniscus Reveals Its Role in the Processing of Multiple Sound Sources
in the Inferior Colliculus of Bats
R. Michael
Burger and
George D.
Pollak
Section of Neurobiology, University of Texas, Austin, Texas 78712
Neurons in the inferior colliculus (IC) that are excited by one ear
and inhibited by the other [excitatory inhibitory (EI) neurons] can
code interaural intensity disparities (IIDs), the cues animals use to
localize high frequencies. Although EI properties are first formed in a
lower nucleus and imposed on some IC cells via an excitatory
projection, many other EI neurons are formed de novo in
the IC. By reversibly inactivating the dorsal nucleus of the lateral
lemniscus (DNLL) in Mexican free-tailed bats with kynurenic acid, we
show that the EI properties of many IC cells are formed de
novo via an inhibitory projection from the DNLL on the opposite
side. We also show that signals excitatory to the IC evoke an
inhibition in the opposite DNLL that persists for tens of milliseconds
after the signal has ended. During that period, strongly suppressed EI
cells in the IC are deprived of inhibition from the DNLL and respond to
binaural signals as weakly inhibited or monaural cells. By relieving
inhibition at the IC, we show that an initial binaural signal
essentially reconfigures the circuit and thereby allows IC cells to
respond to trailing binaural signals that were inhibitory when
presented alone. Thus, DNLL innervation creates a property in the IC
that is not possessed by lower neurons or by collicular EI neurons that
are not innervated by the DNLL. That property is a change in
responsiveness to binaural signals, a change dependent on the reception
of an earlier sound. These features suggest that the circuitry linking
the DNLL with the opposite central nucleus of the IC is
important for the processing of IIDs that change over time, such as the
IIDs generated by moving stimuli or by multiple sound sources that
emanate from different regions of space.
Key words:
GABA; persistent inhibition; precedence effect; inferior
colliculus; sound localization; dorsal nucleus of lateral lemniscus
Copyright © 2001 Society for Neuroscience 0270-6474/01/21134830-14$05.00/0
This article has been cited by other articles:
|
|
|
|
 
Y. Zheng and M. A. Escabi
Distinct Roles for Onset and Sustained Activity in the Neuronal Code for Temporal Periodicity and Acoustic Envelope Shape
J. Neurosci.,
December 24, 2008;
28(52):
14230 - 14244.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Pecka, T. P. Zahn, B. Saunier-Rebori, I. Siveke, F. Felmy, L. Wiegrebe, A. Klug, G. D. Pollak, and B. Grothe
Inhibiting the Inhibition: A Neuronal Network for Sound Localization in Reverberant Environments
J. Neurosci.,
February 14, 2007;
27(7):
1782 - 1790.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
I. Siveke, M. Pecka, A. H. Seidl, S. Baudoux, and B. Grothe
Binaural Response Properties of Low-Frequency Neurons in the Gerbil Dorsal Nucleus of the Lateral Lemniscus
J Neurophysiol,
September 1, 2006;
96(3):
1425 - 1440.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Schuchmann, M. Hubner, and L. Wiegrebe
The absence of spatial echo suppression in the echolocating bats Megaderma lyra and Phyllostomus discolor
J. Exp. Biol.,
January 1, 2006;
209(1):
152 - 157.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. Xie, J. Meitzen, and G. D. Pollak
Differing Roles of Inhibition in Hierarchical Processing of Species-Specific Calls in Auditory Brainstem Nuclei
J Neurophysiol,
December 1, 2005;
94(6):
4019 - 4037.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. G. Sinex, H. Li, and D. S. Velenovsky
Prevalence of Stereotypical Responses to Mistuned Complex Tones in the Inferior Colliculus
J Neurophysiol,
November 1, 2005;
94(5):
3523 - 3537.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. J. Ingham and D. McAlpine
GABAergic Inhibition Controls Neural Gain in Inferior Colliculus Neurons Sensitive to Interaural Time Differences
J. Neurosci.,
June 29, 2005;
25(26):
6187 - 6198.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. J. Tollin, L. C. Populin, and T. C. T. Yin
Neural Correlates of the Precedence Effect in the Inferior Colliculus of Behaving Cats
J Neurophysiol,
December 1, 2004;
92(6):
3286 - 3297.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. J. Ingham and D. McAlpine
Spike-Frequency Adaptation in the Inferior Colliculus
J Neurophysiol,
February 1, 2004;
91(2):
632 - 645.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. E. Bauer, A. Klug, and G. D. Pollak
Spectral Determination of Responses to Species-Specific Calls in the Dorsal Nucleus of the Lateral Lemniscus
J Neurophysiol,
October 1, 2002;
88(4):
1955 - 1967.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
