Context-dependent and dynamic functional influence of corticothalamic pathways to first- and higher-order visual thalamus.

ABSTRACT: Layer 6 (L6) is the sole purveyor of corticothalamic (CT) feedback to first-order thalamus and also sends projections to higher-order thalamus, yet how it engages the full corticothalamic circuit to contribute to sensory processing in an awake animal remains unknown. We sought to elucidate the functional impact of L6CT projections from the primary visual cortex to the dorsolateral geniculate nucleus (first-order) and pulvinar (higher-order) using optogenetics and extracellular electrophysiology in awake mice. While sustained L6CT photostimulation suppresses activity in both visual thalamic nuclei in vivo, moderate-frequency (10 Hz) stimulation powerfully facilitates thalamic spiking. We show that each stimulation paradigm differentially influences the balance between monosynaptic excitator

SUBMITTER: Kirchgessner MA 

PROVIDER: S-EPMC7293611 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature