Dr. Anna Schroeder, a leading neuroscientist, graces our show in this episode to shed light on a crucial yet understudied facet of neocortical circuits. Top-down projections in our brain act as a bridge between previous experiences, current objectives, and the sensory neocortex, playing a pivotal role in our perception and memory. While excitatory pathways have been typically associated with top-down control, inhibitory top-down projections remain a largely uncharted territory.

Dr. Schroeder's ground-breaking research, employing a unique blend of synaptic two-photon calcium imaging, circuit mapping, cortex-dependent learning, and chemogenetics in mice, uncovers the GABAergic afferents from the subthalamic zona incerta as a significant source of top-down input to the neocortex. The zona incerta's inhibitory projections are critical for learn ...