Check out our preprint for details! We also look at the development of layer 6 corticothalamic neuron dendrites, which differ from axons in both time course and activity dependence, the maturation of PV interneuron physiology and connectivity, and more (end)

Synaptogenesis is selective for parvalbumin interneurons within layer 6, and in translaminar connections to layer 4. This is despite these interneurons being far less abundant than neighboring excitatory neurons in both layers (6/7)

Do excitatory neurons selectively innervate their targets from the beginning, or make synapses promiscuously and then eliminate the off-target ones? We find that layer 6 corticothalamic neurons selectively form functional synapses to parvalbumin interneurons (5/7)

How does developmental neuronal activity affect axon arbor growth? We found that hyperpolarizing layer 6 corticothalamic neurons increased axon arbor elaboration specifically in layer 6, but not in layers 4 or 5 (4/7)

When and how do layer 6 corticothalamic neurons elaborate their intracortical axon branches? Using sparse labeling and lightsheet imaging we found two stages of outgrowth separated by a period of stasis in the first two postnatal weeks (3/7)

We focused on layer 6 corticothalamic neurons, which have a striking preference for connections to inhibitory interneurons that express parvalbumin over other excitatory cell types. In mice, this synaptic preference for inhibitory neurons can regulate cortical responses to sensory input (2/7)