The transcriptional cortical response to daily torpor in Phodopus sungorus.

Torpor is an essential evolutionary strategy that allows mammals to conserve resources under extreme environmental conditions. Although the hypothalamus is a key regulator of systemic acclimatisation to energy scarcity and reduced temperature, it remains unclear how the cortex, with its high metabolic demand, endures this state. Here, we performed RNA sequencing on neuronal and non-neuronal nuclei isolated from the cortex of Djungarian hamsters (Phodopus sungorus) across different seasonal and metabolic states. We found that non-neuronal cells primarily adjust during the seasonal transition from a summer to winter phenotype, with differential expression of genes linked to circadian rhythm. In contrast, cortical neurons exhibited major transcriptional changes during daily torpor, marked by increased expression of RNA catabolic pathways. Finally, comparison with published hypothalamic datasets revealed distinct transcriptional programmes between the cortex and hypothalamus. Together, these findings highlight cell type- and region-specific transcriptional changes that preserve CNS integrity during metabolic depression.