TY - JOUR TI - Fast and slow feedforward inhibitory circuits for cortical odor processing AU - Suzuki, Norimitsu AU - Tantirigama, Malinda LS AU - Aung, K Phyu AU - Huang, Helena HY AU - Bekkers, John M A2 - Ding, Jun A2 - Huguenard, John R A2 - Zhu, J Julius VL - 11 PY - 2022 DA - 2022/03/17 SP - e73406 C1 - eLife 2022;11:e73406 DO - 10.7554/eLife.73406 UR - https://doi.org/10.7554/eLife.73406 AB - Feedforward inhibitory circuits are key contributors to the complex interplay between excitation and inhibition in the brain. Little is known about the function of feedforward inhibition in the primary olfactory (piriform) cortex. Using in vivo two-photon-targeted patch clamping and calcium imaging in mice, we find that odors evoke strong excitation in two classes of interneurons – neurogliaform (NG) cells and horizontal (HZ) cells – that provide feedforward inhibition in layer 1 of the piriform cortex. NG cells fire much earlier than HZ cells following odor onset, a difference that can be attributed to the faster odor-driven excitatory synaptic drive that NG cells receive from the olfactory bulb. As a result, NG cells strongly but transiently inhibit odor-evoked excitation in layer 2 principal cells, whereas HZ cells provide more diffuse and prolonged feedforward inhibition. Our findings reveal unexpected complexity in the operation of inhibition in the piriform cortex. KW - piriform cortex KW - inhibition KW - olfaction JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -