| Different subtypes of GABAergic neurons in sensory cortex exhibit diverse morphology, histochemical markers, patterns of connectivity and sensitivity to neuromodulators. These subtypes likely play distinct roles in cortical function, but their in vivo response properties remain unclear. We used in vivo calcium imaging, combined with immunohistochemical and genetic labels, to record visual responses in excitatory neurons and up to three distinct subtypes of GABAergic neurons in layer 2/3 of mouse visual cortex. Excitatory neurons had sharp response selectivity for stimulus orientation and spatial frequency, while all GABAergic subtypes had broader selectivity. Further, bias in the responses of GABAergic neurons toward particular orientations or spatial frequencies tended to reflect net biases of the surrounding neurons. We also developed techniques to record the activity of GABAergic neurons in the awake mouse to better understand the roles of GABAergic neurons in mediating behavioral modulation of cortical circuits. |
