Owing to the well-studied feed-forward anatomy, the thalamus is classically described as a relay station between the sensory periphery and the cortex. However, the complex dynamic interaction between the thalamic and cortical structures is perhaps the key element in establishing representations that ultimately result in perception of our sensory environment. In these projects, we quantify information transmission in the thalamocortical pathway under varying stimulation conditions and sensory modalities.
Information transmission in the vibrissa pathway
Given the sensitivity of the thalamocortical synapse to closely timed spikes and the importance of fine timing precision for the faithful representation of sensory information, the modulation of thalamic population timing over these time scales is likely important for cortical representations of the dynamic natural sensory environment. The canonical network architecture of the thalamocortical circuit, along with the extensive literature on the discretized anatomy of the rodent vibrissa system, makes this an ideal model system for studying the transmission of information in the thalamocortical circuit.
Using this pathway, we show that sensory adaptation differentially influences thalamic and cortical activity in a manner that fundamentally changes the nature of the information conveyed about the sensory input. Specifically, from the perspective of an ideal observer of spiking activity, the cortical neurons show a degraded performance in detecting vibrissal deflections with adaptation, while showing an enhancement in discriminating between deflections of different velocities. Analysis of simultaneously recorded thalamic neurons did unveil, however, an analogous adaptive change in thalamic synchrony that mirrors the observations of cortical response magnitude. The results here suggest an adaptive shift in the coding strategy that has direct functional consequences regarding the nature of information relayed to cortex.
D. R. Ollerenshaw, H. J. V. Zheng, Q. Wang, and G. B. Stanley, The adaptive trade-off between detection and discrimination in cortical representations and behavior, Neuron., Mar 5;81(5):1152-64, 2014. PDF
He J. V. Zheng, Qi Wang, & Garrett B. Stanley, Adaptive Shaping of Cortical Response Selectivity in the Vibrissa Pathway, J Neurophysiol, 2015. PDF