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This Article Full Text Full Text (PDF) Supplemental Figures All Versions of this Article: 102/5/2638    most recent 00577.2009v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Asari, H. Articles by Zador, A. M. PubMed PubMed Citation Articles by Asari, H. Articles by Zador, A. M.

RESEARCH-ARTICLE

Long-Lasting Context Dependence Constrains Neural Encoding Models in Rodent Auditory Cortex

Cold Spring Harbor Laboratory, Watson School of Biological Sciences, Cold Spring Harbor, New York

Submitted 6 July 2009; accepted in final form 12 August 2009

ABSTRACT

Acoustic processing requires integration over time. We have used in vivo intracellular recording to measure neuronal integration times in anesthetized rats. Using natural sounds and other stimuli, we found that synaptic inputs to auditory cortical neurons showed a rather long context dependence, up to 4 s ( 1 s), even though sound-evoked excitatory and inhibitory conductances per se rarely lasted 100 ms. Thalamic neurons showed only a much faster form of adaptation with a decay constant <100 ms, indicating that the long-lasting form originated from presynaptic mechanisms in the cortex, such as synaptic depression. Restricting knowledge of the stimulus history to only a few hundred milliseconds reduced the predictable response component to about half that of the optimal infinite-history model. Our results demonstrate the importance of long-range temporal effects in auditory cortex and suggest a potential neural substrate for auditory processing that requires integration over timescales of seconds or longer, such as stream segregation.