Project description:Transcriptome analyses were performed to further disentangle hypothalamic control of spontaneous daily torpor in the Djungarian Hamster (Phodopus sungorus) acclimated to winter-like short photoperiod (SP). Samples of hypothalamic core areas suprachiasmatic nucleus (SCN) and paraventricular nucleus (PVN) were taken about seven hours after lights on (ZT07). After a de novo assembly of transcriptomes and a mapping against RefSeq of the house mouse (Mus musculus), data from hamsters sampled with hypothermic (HT) core body temperature during torpor arousal on a torpor-day (TD) were compared with data from hamsters sampled with normothermic (NT) core body temperature on a torpor-free day (TFD). The data must be interpreted with respect to the metabolic and seasonal context, as described in the manuscript of the original research.
Project description:Torpor is an essential evolutionary strategy that allows mammals to conserve resources under extreme environmental conditions. While the hypothalamus is a key regulator of systemic adaptations 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 adapt during the seasonal transition from summer to winter phenotype, with differential expression of genes linked to circadian rhythm. In contrast, cortical neurons exhibited major transcriptional changes only between normothermia and hypothermia, marked by increased expression of RNA catabolic pathways. Finally, comparison with published hypothalamic datasets revealed distinct transcriptional programs between the cortex and hypothalamus. Together, these findings highlight cell type- and region-specific adaptations that preserve CNS integrity during metabolic depression.
