AbstractTransient Receptor Potential Ankyrin 1 (TRPA1) is a non-selective cation channel, which is broadly expressed throughout the body. Despite its expression in the mammalian cortex, little is known about the contribution of TRPA1 to cortical function. Here we investigate the role of TRPA1 in sensory information processing by performing electrophysiological recording and 2-photon calcium imaging from two sensory areas in mice: the primary vibrissal somatosensory cortex (vS1) and the primary visual cortex (V1). In vS1, local activation of TRPA1 by its agonist AITC significantly increased the spontaneous activity of cortical neurons, their evoked response to vibrissal stimulation, and their response range, consistent with a positive gain modulation. TRPA1 inhibition with HC-030031 reversed these modulations to below initial control gains. The gain modulations were absent in TRPA1 Knockout mice. In V1, TRPA1 activation increased the gain of direction and orientation selectivity similarly to the gain modulations observed in vS1 cortex. Linear decoding analysis of V1 population activity confirmed faster and more reliable encoding of visual signals in the presence of TRPA1 activation. Overall, our findings reveal a physiological role for TRPA1 in enhancing sensory signals in the mammalian cortex.