| First Author | Boyd AM | Year | 2012 |
| Journal | Neuron | Volume | 76 |
| Issue | 6 | Pages | 1161-74 |
| PubMed ID | 23259951 | Mgi Jnum | J:249922 |
| Mgi Id | MGI:6100771 | Doi | 10.1016/j.neuron.2012.10.020 |
| Citation | Boyd AM, et al. (2012) Cortical feedback control of olfactory bulb circuits. Neuron 76(6):1161-74 |
| abstractText | Olfactory cortex pyramidal cells integrate sensory input from olfactory bulb mitral and tufted (M/T) cells and project axons back to the bulb. However, the impact of cortical feedback projections on olfactory bulb circuits is unclear. Here, we selectively express channelrhodopsin-2 in olfactory cortex pyramidal cells and show that cortical feedback projections excite diverse populations of bulb interneurons. Activation of cortical fibers directly excites GABAergic granule cells, which in turn inhibit M/T cells. However, we show that cortical inputs preferentially target short axon cells that drive feedforward inhibition of granule cells. In vivo, activation of olfactory cortex that only weakly affects spontaneous M/T cell firing strongly gates odor-evoked M/T cell responses: cortical activity suppresses odor-evoked excitation and enhances odor-evoked inhibition. Together, these results indicate that although cortical projections have diverse actions on olfactory bulb microcircuits, the net effect of cortical feedback on M/T cells is an amplification of odor-evoked inhibition. |
