Contributions of the thalamocortical system towards sound-specific auditory plasticity

Abstract

The function of the auditory cortex is dynamic. Although auditory cortical plasticity can be induced through various approaches such as learning, experience and sensory deprivation, a common property is the frequency-specificity; the change in neuronal receptive field or functional maps is highly specific to the frequency content of the acquired sound. This unique property suggests that precise frequency information must be relayed to the auditory cortex. It is well known that the auditory thalamocortical pathway is the only neural substrate that sends precise frequency information to the auditory cortex. This review addresses the impact of the auditory thalamocortical system on cortical plasticity. The frequency-specificity of auditory cortical plasticity and the tonotopic features of the auditory thalamocortical system are briefly presented. A discussion of the decisive role of thalamocortical system follows. After an exploration of a possible synaptic mechanism, a thalamocortical model is proposed to better interpret the neural mechanisms underlying frequency-specific plasticity of the auditory cortex.