Pathway-specific inputs to the superior colliculus support flexible responses to visual threat.

Behavioral flexibility requires directing feedforward sensory information to appropriate targets. In the superior colliculus, divergent outputs orchestrate different responses to visual threats, but the circuit organization enabling the flexible routing of sensory information remains unknown. To determine this structure, we focused on inhibitory projection (Gad2) neurons.

Septal GABAergic inputs to CA1 govern contextual memory retrieval.

The CA1 output region of the hippocampus plays an essential role in the retrieval of episodic memories. γ-Aminobutyric acid-releasing (GABAergic) long-range projections from the medial septum (MS) densely innervate the hippocampus, but whether septal inputs regulate memory expression remains elusive. We found that the MS to CA1 connection is recruited during recall of a contextual fear memory.

A Platform for Brain-wide Volumetric Functional Ultrasound Imaging and Analysis of Circuit Dynamics in Awake Mice.

Imaging large-scale circuit dynamics is crucial to understanding brain function, but most techniques have a limited depth of field. Here, we describe volumetric functional ultrasound imaging (vfUSI), a platform for brain-wide vfUSI of hemodynamic activity in awake head-fixed mice. We combined a high-frequency 1,024-channel 2D-array transducer with advanced multiplexing and high-performance computing for real-time 3D power Doppler imaging at a high spatiotemporal resolution (220 × 280 × 175 μm, up to 6 Hz).