​​​​FROZEN MEMORIES: USING HIBERNATION TO REVEAL NEURAL MECHANISMS OF MEMORY

All animals use memories of their past to guide future behavior, exploiting opportunities while avoiding threats. Although much is known about the neural basis of memory, this knowledge comes from a limited number of species in a controlled lab setting. In diverse species and habitats that have so far remained inaccessible to neuroscientific study, memory mechanisms may substantially differ because brains are highly adaptive, inventing solutions to ecological challenges. To derive general principles of memory, we must leverage new tools and animal models to move toward the naturalistic contexts in which brains evolved.

One extreme ecological challenge likely to shape memory circuits is hibernation – to survive food scarcity, thousands of species enter this state of profound metabolic suppression that lasts from a few hours to many weeks. Unlike sleep, during which neural activity helps to preserve memories, hibernation silences neural activity, potentially erasing memories and leaving animals at risk. Animals must remember where to find food and shelter to survive, and thus must have evolved adaptive neural mechanisms to protect memory.

Here, I present ongoing efforts to establish two new, complementary animal models for studying memory: 1) Peromyscus (deer mice), which frequently enter short bouts of hibernation to conserve energy; and 2) Qrfp-iCre transgenic house mice, in which activating a subset of hypothalamic neurons mimics hibernation, thereby enabling precise temporal control. By combining an ethological memory task with high-density Neuropixels 2.0 probes, I aim to reveal the effects of hibernation on hippocampal activity, and in turn, on long-term memory.