Plasticity of temporal information processing in the primary auditory
cortex
Michael P. Kilgard1
& Michael M. Merzenich1, 2
1
Coleman Laboratory, Departments of Otolaryngology and Physiology, Keck Center for Integrative Neuroscience, University of California at San Francisco, San Francisco, California 94143-0444, USA
2
Scientific Learning Corporation, 1995 University Avenue, Berkeley, California 94104-1075, USA
Neurons in the rat primary auditory cortex (A1) generally cannot respond
to tone sequences faster than 12 pulses per second (pps). To test whether
experience can modify this maximum following rate in adult rats, trains of
brief tones with random carrier frequency but fixed repetition rate were paired
with electrical stimulation of the nucleus basalis (NB) 300 to 400 times per
day for 20−25 days. Pairing NB stimulation with 5-pps stimuli markedly
decreased the cortical response to rapidly presented stimuli, whereas pairing
with 15-pps stimuli significantly increased the maximum cortical following
rate. In contrast, pairing with fixed carrier frequency 15-pps trains did
not significantly increase the mean maximum following rate. Thus this protocol
elicits extensive cortical remodeling of temporal response properties and
demonstrates that simple differences in spectral and temporal features of
the sensory input can drive very different cortical reorganizations.
