Histological analysis of sleep and circadian brain circuitry in cranial radiation-induced hypersomnolence (C-RIH) mouse model

Abstract

Disrupted sleep, including daytime hypersomnolence, is a core symptom reported by primary brain tumor patients and often manifests after radiotherapy. The biological mechanisms driving the onset of sleep disturbances after cranial radiation remains unclear but may result from treatment-induced injury to neural circuits controlling sleep behavior, both circadian and homeostatic. Here, we develop a mouse model of cranial radiation-induced hypersomnolence which recapitulates the human experience. Additionally, we used the model to explore the impact of radiation on the brain. We demonstrated that the DNA damage response following radiation varies across the brain, with homeostatic sleep and cognitive regions expressing higher levels of γH2AX, a marker of DNA damage, than the circadian suprachiasmatic nucleus (SCN). These findings were supported by in vitro studies comparing radiation effects in SCN and cortical astrocytes. Moreover, in our mouse model, MRI identified structural effects in cognitive and homeostatic sleep regions two-months post-treatment. While the findings are preliminary, they suggest that homeostatic sleep and cognitive circuits are vulnerable to radiation and these findings may be relevant to optimizing treatment plans for patients.

Electrogelated drug-embedded silk/gelatin/rGO degradable electrode for anti-inflammatory applications in brain-implant systems

“…CTXTNA2, which is a type I astrocyte cell line isolated from the cortex of 1-day old rats, was used in the neuroscience study. 28 This kind of cell was cultured in DMEM supplemented with 10% fetal bovine serum (FBS) and 1% penicillin-streptomycin and maintained in a 5% CO 2 humidified atmosphere at 37 1C. On the other hand, PC12 is a cell line derived from a pheochromocytoma of the rat adrenal medulla.…”

“…The silk fibroin has a negative charge of À14.87 mV due to its isoelectric point at pH = 4.2 being lower than the solution pH. 28 The gelatin showed negative charge of À4.14 mV because its isoelectric point at pH = 6-9 was slightly lower than the solution pH of silk fibroin, while the Sg hybrid solution with the mass ratio of 1/1 displayed the net charge as À7.25 mV. It indicated a balance of charge between silk fibroin and gelatin.…”