Cold Engrams - at the Interface of Memory and Metabolism
Abstract
Mammals experience temperature flux in their environment and must readily adapt for optimal function. Maintenance of core body temperature within a narrow range is essential for the survival of all animals, and faced with a cold challenge they maintain their homeostasis through autonomic physiological mechanisms such as thermogenesis and altered behavior activity. However, it is unknown whether animals preemptively trigger thermogenic response as a way to prepare for a future cold experience. Here we will investigate whether individuals can be trained to form memories of cold exposure, and whether the recall of such memories can trigger anticipatory thermogenic responses in both the brain and in the body. We will identify the outcomes of cold memory recall by measuring whole body metabolism, local metabolic activity in fat tissue, neuronal activity in the hypothalamic regions of the brain, and animal behavior. We will identify and genetically label the memory engram ensembles that underlie the formation of cold memories in the hippocampus and surrounding regions. We will then optogenetically reactivate these ensembles and measure the effect on whole body metabolism and warmth-seeking behavior and will test the importance for these ensembles to both learned and innate thermogenic activity. Lastly, we will investigate how cold engrams can be linked with innate cold sensing neurons in the hypothalamus. We will characterize the engram cell connectivity pattern between the hippocampus and the hypothalamus ensembles, and the functional impact of its plasticity following cold experiences. In doing so, we will define how learned thermoregulation is mechanistically controlled by the innate homeostatic centers of the brain.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 06, 2025
- Source ID
- FA95502410258
Entities
People
- Tomás J Ryan
Organizations
- Air Force Office of Scientific Research
- Trinity College Dublin
- United States Air Force