RESEARCH INTERESTS

Representation of information in cortical and thalamocortical networks.

RESEARCH TECHNIQUES

Intracellular and optical recordings in vivo and in vitro.

RESEARCH SUMMARY

My lab's focus is on how the intrinsic cellular properties of neurons and the characteristics of local neuronal networks contribute to the encoding of peripheral sensory input in two separate animal models: (i) the cat visual system and (ii) the rat whisker system. Responses to sensory stimuli are recorded from the neocortex and thalamus in vivo using intracellular and optical voltage-sensitive dye methods. These methods are also applied to the brain slice preparation in order to further study the dynamics of cortical microcircuitry.

Using these techniques, we address a number of basic questions. Do differences in intrinsic cellular properties across individual neurons contribute to the representation of sensory inputs? How do local network properties such as feed-forward and feed-back inhibition shape the representation of peripheral stimuli? How do single cells acquire selectivity to specific stimulus features? How are thalamic and cortical receptive fields generated? How are responses to multiple sensory inputs integrated at different levels in the brain?

KEY WORDS:   cortex, thalamus, sensory coding, intracellular, optical, barrels, vision

KEY REFERENCES

Contreras D, Palmer L (2003) Response to contrast of electrophysiologically defined cell classes in primary visual cortex. J Neurosci 23:6936-6945.

Wilent WB, Contreras D (2004) Synaptic responses to whisker deflections in rat barrel cortex as a function of cortical layer and stimulus intensity. J Neurosci 24:3985-3998.

Cardin JA, Palmer LA, Contreras D (2005) Stimulus-dependent gamma (30-50 Hz) oscillations in simple and complex fast rhythmic bursting cells in primary visual cortex. J Neurosci 25:5339-5350.

Wilent WB, Contreras D (2005) Dynamics of excitation and inhibition underlying stimulus selectivity in rat somatosensory cortex. Nat Neurosci 8:1364-1370

Civillico EF, Contreras D (2006) Integration of evoked responses in supragranular cortex studied with optical recordings in vivo. J Neurophysiol 96:336-351.

Higley MJ, Contreras D (2006) Balanced excitation and inhibition determine spike timing during frequency adaptation. J Neurosci 26:448-457.