| First Author | Ledderose JMT | Year | 2023 |
| Journal | Cereb Cortex | Volume | 33 |
| Issue | 23 | Pages | 11354-11372 |
| PubMed ID | 37851709 | Mgi Jnum | J:349731 |
| Mgi Id | MGI:7568740 | Doi | 10.1093/cercor/bhad371 |
| Citation | Ledderose JMT, et al. (2023) Layer 1 of somatosensory cortex: an important site for input to a tiny cortical compartment. Cereb Cortex 33(23):11354-11372 |
| abstractText | Neocortical layer 1 has been proposed to be at the center for top-down and bottom-up integration. It is a locus for interactions between long-range inputs, layer 1 interneurons, and apical tuft dendrites of pyramidal neurons. While input to layer 1 has been studied intensively, the level and effect of input to this layer has still not been completely characterized. Here we examined the input to layer 1 of mouse somatosensory cortex with retrograde tracing and optogenetics. Our assays reveal that local input to layer 1 is predominantly from layers 2/3 and 5 pyramidal neurons and interneurons, and that subtypes of local layers 5 and 6b neurons project to layer 1 with different probabilities. Long-range input from sensory-motor cortices to layer 1 of somatosensory cortex arose predominantly from layers 2/3 neurons. Our optogenetic experiments showed that intra-telencephalic layer 5 pyramidal neurons drive layer 1 interneurons but have no effect locally on layer 5 apical tuft dendrites. Dual retrograde tracing revealed that a fraction of local and long-range neurons was both presynaptic to layer 5 neurons and projected to layer 1. Our work highlights the prominent role of local inputs to layer 1 and shows the potential for complex interactions between long-range and local inputs, which are both in position to modify the output of somatosensory cortex. |
