The primary auditory cortex in the adult is physiologically plastic, rather than static as has been traditionally assumed. Behavioral learning produces shifts of the frequency tuning of auditory cortical neurons toward or to the frequency of an acquired behaviorally important sound. Learning-induced plasticity is due to associative processes rather than arousal or attention, is highly specific to the important frequency, is rapidly acquired and lasts indefinitely, as tested for months. Therefore, the basic processing of acoustic frequency is not simply determined by the physical parameters of sound but also by its acquired behavioral importance. Understanding the highest level of the auditory system depends upon understanding how learning modifies auditory information processing. The goal of this project is to initiate the solution of this problem. Specifically, it will determine the effects of learninbg on fundmanetal parameters of response to acoustic frequency: Characteristic frequency (CF), threshold level of the CF (Th) and bandwidth or response at levels above threshold (BW). These parameters provide sensitive measures of information processing -- CF indexes tuning; Th indexes sensitivity; BW indexes selectivity. This will be accomplished by determiing in adult behaving guinea pigs, the response areas (frequency by intensity) of neighboring single neurons before and at various intervals after different types of behavioral training: habituation, sensitization, classical conditioning,instrumental conditioning. Additionally, the rate of development of learning-induced plasticity will be determined. This project will help explain learning effects in the normal human. Moreover, it has significance for understanding the learning that occurs in pathologies and therapies, such as learning to perceive speech following cochlear implants and for recently identified learning-based remediation of acoustic processing deficits in dyslexia.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
2R01DC002346-05
Application #
2408755
Study Section
Special Emphasis Panel (ZRG1-SEN (01))
Project Start
1993-09-20
Project End
2002-08-31
Budget Start
1997-09-01
Budget End
1998-08-31
Support Year
5
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of California Irvine
Department
Biology
Type
Other Domestic Higher Education
DUNS #
161202122
City
Irvine
State
CA
Country
United States
Zip Code
92697
Rutkowski, Richard G; Weinberger, Norman M (2005) Encoding of learned importance of sound by magnitude of representational area in primary auditory cortex. Proc Natl Acad Sci U S A 102:13664-9
Rutkowski, Richard G; Miasnikov, Alexandre A; Weinberger, Norman M (2003) Characterisation of multiple physiological fields within the anatomical core of rat auditory cortex. Hear Res 181:116-30
Weinberger, Norman M (2003) The nucleus basalis and memory codes: auditory cortical plasticity and the induction of specific, associative behavioral memory. Neurobiol Learn Mem 80:268-84
Galvan, Veronica V; Weinberger, Norman M (2002) Long-term consolidation and retention of learning-induced tuning plasticity in the auditory cortex of the guinea pig. Neurobiol Learn Mem 77:78-108
Galvan, Veronica V; Chen, Jemmy; Weinberger, Norman M (2002) Differential thresholds of local field potentials and unit discharges in rat auditory cortex. Hear Res 167:57-60
McLin 3rd, Dewey E; Miasnikov, Alexandre A; Weinberger, Norman M (2002) Induction of behavioral associative memory by stimulation of the nucleus basalis. Proc Natl Acad Sci U S A 99:4002-7
McLin 3rd, Dewey E; Miasnikov, Alexandre A; Weinberger, Norman M (2002) The effects of electrical stimulation of the nucleus basalis on the electroencephalogram, heart rate, and respiration. Behav Neurosci 116:795-806
Galvan, V V; Chen, J; Weinberger, N M (2001) Long-term frequency tuning of local field potentials in the auditory cortex of the waking guinea pig. J Assoc Res Otolaryngol 2:199-215
Miasnikov, A A; McLin 3rd, D; Weinberger, N M (2001) Muscarinic dependence of nucleus basalis induced conditioned receptive field plasticity. Neuroreport 12:1537-42
Cruikshank, S J; Weinberger, N M (2001) In vivo Hebbian and basal forebrain stimulation treatment in morphologically identified auditory cortical cells. Brain Res 891:78-93

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