12 Amazing Scientific Discoveries From Last Year
If you work with (or just nerd out on) mice, rats, zebrafish, flies, and the rest of the small-animal science universe, last year was a banner year for scientific discoveries. And not the “incremental pathway paper” kind of scientific discoveries—the jaw-drop kind: two-dad mice, woolly gene-edited mice, stroke recovery interventions that actually moved the needle, and brain research that treats the system like a system. The models may be small, but these scientific discoveries aren’t.
This is our Small Animals Edition: scientific discoveries where small animal models were the core engine of the work.
1) Adult bi-paternal mice (two dads) that made it to adulthood
Researchers pushed past long-standing imprinting barriers and produced adult bi-paternal mice using targeted imprinting edits—one of the clearest “wait, WHAT?” moments of the year.
Imprinting errors are complex, unpredictable, and a major obstacle in embryonic and induced stem cells and in animal cloning; there’s no single fix. This study tackled imprinting at the source by using bi-paternal mouse embryos (normally non-viable due to severe imprinting defects) and editing 20 key imprinted loci, ultimately achieving the development of adult animals (albeit with a low survival rate). This has tremendous implications for embryonic development!
2) “Woolly mice” with mammoth-like hair traits
Woolly mammoth de-extinction aims to recreate cold-adaptive traits by engineering living relatives. Yes, the internet made this weird, but the underlying science is real: edits linked to hair growth/texture were tested in mice as a proxy for extinct-trait reconstruction work.
This study uses mice as a fast testbed for those trait-driving genes. Researchers used CRISPR to build multiplex-edited mice with changes in both hair morphology and lipid metabolism genes, achieving high-efficiency edits across up to seven genes to study “woolly” hair and cold tolerance biology.
3) A zebrafish heart-repair program that also helped mouse hearts
Unlike adult mammalian hearts, zebrafish regenerate heart tissue after injury like it’s no big deal. A 2025 study tied part of that capacity to HMGA1, and showed improved repair in mice too.
This study shows that insertion of Hmga1, usually not expressed in mammalian heart, drives chromatin remodeling that switches on a regenerative program, stimulating the production of new, fully functional cardiac tissue. This makes it a strong candidate target for boosting heart repair after damage.
4) A “pill for stroke rehab”
UCLA teams mapped mechanisms behind rehab-driven recovery and identified a drug candidate that mimics aspects of rehabilitation effects in mice—big implications if it translates.
UCLA researchers found that stroke can disrupt brain connections far from the injury site, by affecting inhibitory parvalbumin interneurons that support key brain rhythms. Traditional rehabilitation can help restore function to these pathways, but the experimental drug DDL-920, a GABA modulator, helped restore movement control in mice, suggesting an additional path to functional recovery.
5) Sound waves improve hemorrhagic stroke outcomes in mice
NIH highlighted work using high-frequency sound waves to help clear debris and improve outcomes after stroke in mouse models.
Hemorrhagic stroke (bleeding in the brain) causes about 10% of all strokes. Researchers used high-frequency ultrasound in mouse stroke models to help clear harmful cellular debris and improve recovery, showing a way to shift the brain’s cleanup response. This non-invasive technique (that already meets FDA safety guidelines) could eventually support a safer, faster stroke treatment.
6) A novel drug to reduce brain damage after ischemic stroke
Cambridge researchers reported a drug strategy in mice aimed at reducing ischemia-reperfusion injury, which can happen when blood flow is restored after a blood clot is removed.
The team built a mouse model that mimics mechanical thrombectomy, the best available stroke treatment, to test acidified disodium malonate (aDSM)’s protective effect against reperfusion injury. The study found that delivering aDSM during a thrombectomy-style intervention reduced reperfusion-induced brain damage by up to 60%.
7) Brain lithium deficiency tied to Alzheimer’s pathology (mouse models + human data)
A Nature article tied endogenous brain lithium levels to Alzheimer’s Dementia-like pathology in mice, and explored lithium orotate replacement effects—provocative and very testable.
Researchers found that in humans, endogenous lithium in the brain appears to support cognitive resilience. It is uniquely reduced in people with mild cognitive impairment, with further loss in Alzheimer’s linked to amyloid binding.
Testing this hypothesis in mouse models, researchers saw lowering brain lithium worsened amyloid and tau pathology and accelerated cognitive decline. Treatment with lithium orotate, which binds amyloid less, helped prevent pathology and memory loss—suggesting disrupted lithium balance may be an early predictor of Alzheimer’s.
8) Psilocybin improved survival in aged mice
One of the more “didn’t have that on my 2025 bingo card” results: psilocybin/psilocin is linked to improved survival in aged mice and a reduction in cellular aging markers.
Psilocybin has strong clinical interest, but its broader biology is still being mapped. This study reports that psilocin, the active compound in psilocybin, extended cellular lifespan, and psilocybin increased longevity in aged mice, suggesting it may act as an anti-aging agent. Groovy!
9) Human “accelerated” DNA enhancer enlarges mouse neocortex by boosting WNT signaling
Researchers tested a human “accelerated region” DNA enhancer called HARE5—a regulatory sequence active in brain development that influences the WNT receptor Frizzled8.
When the human variant was inserted into mice, it increased neural progenitor self-renewal and later neurogenesis, producing larger neocortices with more excitatory neurons. This, combined with HARE5-induced glial cell renewal, lead to measurable shifts in functional independence between cortical regions.
Follow-up work in human vs chimp neural progenitors and organoids showed that human-specific sequence changes increase enhancer activity, amplifying canonical WNT signaling—evidence that small regulatory DNA edits can directly reshape cortical development.
10) Rat “moment of decision” dynamics captured in neural data
This study looked at the transition into commitment—how neural population activity shifts as a rat’s decision snaps into place. Researchers took simultaneous recordings of hundreds of neurons, and then programmed those readings into an unsupervised deep learning based method to identify a decision-making shift in rat brains that may help explain how minds “commit” to a choice.
It’s not proven in humans yet, but the idea is that brains may move from being open to new input to becoming more locked-in once a decision is made.
11) Brain-wide “priors” mapped in mice
Recordings taken by the International Brain Laboratory showed how prior expectations are represented across the mouse brain. If you like big-data neuro, you’ll expect great things!
The researchers tested how mice represent prior expectations during a visual decision task. Over the course of the task, the mice learned from previous trials, which produced a unique neural signature. This neural signature appeared in roughly 20–30% of recorded brain regions, spanning early sensory pathways through motor and higher-order cortical areas. The results support a distributed, Bayesian-like model where prior information is integrated across many interacting regions—not confined to “decision-making” areas.
12) Fruit fly larvae sense electric fields
A Current Biology article highlighted evidence that fruit fly larvae are able to sense the presence and directionality of electric fields.
The study shows that Drosophila melanogaster larvae display measurable behavioral responses to electric fields, demonstrating that electric-field sensing can shape navigation even in simple animals.
The researchers also pinpointed a single pair of neurons that drives this response, offering a clear neural entry point for studying how biological systems detect and act on electrical cues.
Keeping the science going with your own scientific discoveries
Scientific discoveries are fun. But the day-to-day work—consistent technique, compliance, and reproducibility—is what turns scientific discoveries into real progress. If you want practical guidance on small animal anesthesia, monitoring, recovery, and surgical workflows (or you’re upgrading equipment and want to avoid expensive mistakes that slow down scientific discoveries), check out the Kent Scientific blog (KentConnects) and our small animal research workflow resources built for real labs and vet teams—because the best scientific discoveries still depend on rock-solid execution.
