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Published online: 5 November 2001, doi:10.1038/nn760
December 2001 Volume 4 Number 12 pp 1230 - 1237
Differential synaptic processing separates stationary from transient inputs to the auditory cortex
Marco Atzori1, Saobo Lei1, D. Ieuan P. Evans1, Patrick O. Kanold2, Emily Phillips-Tansey1, Orinthal McIntyre1 & Chris J. McBain1
1. LCMN/NICHD/NIH, Rm 5A72, Bldg 49, Convent Drive, Bethesda, Maryland 20892-4495, USA
2. Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205, USA
Correspondence should be addressed to C J McBain. e-mail: chrismcb@codon.nih.gov
Sound features are blended together en route to the central nervous system before being discriminated for further processing by the cortical synaptic network. The mechanisms underlying this synaptic processing, however, are largely unexplored. Intracortical processing of the auditory signal was investigated by simultaneously recording from pairs of connected principal neurons in layer II/III in slices from A1 auditory cortex. Physiological patterns of stimulation in the presynaptic cell revealed two populations of postsynaptic events that differed in mean amplitude, failure rate, kinetics and short-term plasticity. In contrast, transmission between layer II/III pyramidal neurons in barrel cortex were uniformly of large amplitude and high success (release) probability (Pr). These unique features of auditory cortical transmission may provide two distinct mechanisms for discerning and separating transient from stationary features of the auditory signal at an early stage of cortical processing.
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