164 — Medial preoptic circuit induces hunting-like actions to target objects and prey

A neural circuit [in the hypothalamus] that induces hunting and chasing behavior https://t.co/bPKk5qmfiG pic.twitter.com/HPFaj8YETv

— Adam J Calhoun (@neuroecology) January 29, 2018

Thanks Adam J Calhoun for posting!

Mice hunt for crickets (among other prey). When the cricket fits inside the binocular region of the mouse’s visual field — the space in front of the head visible to both of the mouse’s eyes — the mouse is able to fixate on the target and pursue it in a hunting / chasing behavior.

The circuitry for this process was not well-understood. Lesions in the anterior hypothalamic region (specifically, the medial preoptic area, or MPA) seemed to prevent animals from “hoarding” (pursuing objects and bringing them back to a nest) but it wasn’t obvious how this region was integrated into the complex behavior.

To determine which connections were responsible for mediating this behavior, Park et al trained mice to follow and engage with a colored cube “toy” in their environment. When the connections of MPA CaMKII$\alpha$ neurons to those in the ventral periaqueductal gray (vPAG) were stimulated, the mice engaged an order of magnitude more with the movable cube. When these neurons were not stimulated, the mice failed to show any more interest in the cube than usual.

The MPA-vPAG circuit also seems to mediate social/nonsocial behavior: During stimulation, mice were more likely to pay attention to inanimate 3D (not 2D!) objects or prey than to peers (both male and female) in their environment.