A Clonogenic Survival Assay of Neural Stem Cells in Rat Spinal Cord after Exposure to Ionizing Radiation
Bibliographic record
Abstract
Neural stem cells play an important role in neurogenesis of the adult central nervous system (CNS). Inhibition of neurogenesis has been suggested to be an underlying mechanism of radiation-induced CNS damage. Here we developed an in vivo/ in vitro clonogenic assay to characterize the survival of neural stem cells after exposure to ionizing radiation. Cells were isolated from the rat cervical spinal cord and plated as single cell suspensions in defined medium containing epidermal growth factor and basic fibroblast growth factor. The survival of the proliferating cells was determined by their ability to form neurosphere colonies. The number and size of neurospheres were analyzed quantitatively at day 10, 12, 14 and 16 after plating. Plating cells from 5, 10 and 15 mm of the cervical spinal cord resulted in a linear increase in the number of neurospheres from day 10-16. Compared to the nonirradiated spinal cord, there was a significant decrease in the number and size of neurosphere colonies cultured from a 10-mm length of the rat spinal cord after a single dose of 5 Gy. When dissociated neurospheres derived from a spinal cord that had been irradiated with 5 Gy were allowed to differentiate, the percentages of neurons, oligodendrocytes and astrocytes as determined by immunocytohistochemistry were not altered compared to those from the nonirradiated spinal cord. Secondary neurospheres could be obtained from cells dissociated from primary neurospheres that had been cultured from the irradiated spinal cord. In conclusion, exposure to ionizing radiation reduces the clonogenic survival of neural stem cells cultured from the rat spinal cord. However, neural stem cells retain their pluripotent and self-renewing properties after irradiation. A neurosphere-based assay may provide a quantitative measure of the clonogenic survival of neural stem cells in the adult CNS after irradiation.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".