We are actively working on expanding Translating time!
The translating time model integrates over 1,000 empirically-derived neural transformations to identify corresponding ages across 18 mammalian species (placental and marsupial mammals) including hamsters, mice, rats, rabbits, spiny mice, guinea pigs, ferrets, opossums, cats, rhesus monkeys and humans. On this website, the user can find corresponding ages across any of the 18 mammalian species. We are working to increase the utility of this valuable resource. This work is funded thanks to the NIH.
Some recent projects linked to the translating time project:
Translating time across the lifespan in humans and chimpanzees:
I integrate temporal variation in transcription, behavior, and anatomy (see examples on the lower left panel) to find corresponding ages across the lifespan in humans and chimpanzees. This is the first study integrating across scales of biological organization to find corresponding ages across the lifespan in humans and chimpanzees. Now, we can find corresponding time points between a human and chimpanzee at any age (a few example are on the right panel):
A preprint is available on BioRxiv:
Charvet CJ. 2020. Cutting across structural and transcriptomic scales translates time across the lifespan and resolves the development of frontal cortex circuitry in human evolution. Proc. R. Soc. B. 288: 20202987. Available here.
Translating time during postnatal development in humans and mice:
We consider temporal variation in transcription along with temporal variation in anatomy to find corresponding ages up to 30 years of age in humans and their equivalent in mice. Data and extracted corresponding time points are illustrated here:
Hendy JP, Takahashi E, van der Kouwe AJ, Charvet CJ. 2020. Brain wiring and supragranular-enriched genes linked to protracted human frontal cortex development. Cerebral Cortex. In Press.
Charvet CJ. 2020. Closing the gap from transcription to the structural connectome enhances the study of connections in the human brain. Developmental Dynamics. In Press.
Translating time to predict the tempo of hippocampal neurogenesis in humans:
Postnatal hippocampal neurogenesis is linked to many important functions such as learning, memory, stress, and health. Those links were made from studies done on model organisms, and it isn't clear whether these findings apply to humans. There is a debate as to whether hippocampal neurogenesis ends especially early in humans relative to other species. So, when should hippocampus neurogenesis end in humans if it ends at all? Gathering new data and using the translating time data-set, we use human and non-human model organisms to predict how human hippocampal neurogenesis should vary with age. The study finds that human hippocampal neurogenesis should decline towards hard to detect levels during adolescence. It looks like human hippocampal neurogenesis isn't so special. Rather, it declines at similar rates with that of other studied mammals.
Charvet CJ, Finlay BL. 2018. Comparing adult hippocampal neurogenesis across species: translating time to predict the tempo in humans. Front Neurosci. 12.
Translating time to study the co-evolution of inhibitory and excitatory cell type maturation:
We use the translating time data-set to test for deviations in the maturational timeline of GABAergic and pyramidal neuron maturation in primates and rodents. We find that the maturational timeline of GABAergic and pyramidal production are extended in primates but that their subsequent post-neurogenetic maturation is conserved. Modifications to developmental programs generating these cell types impact how our brain processes information.
Charvet CJ, Šimić G, Kostović I, Knezović V, Vukšić M, Leko MB, Takahashi E, Sherwood CC, Wolfe MD, Finlay BL. Coevolution in the timing of GABAergic and pyramidal neuron maturation in primates. Proc. R. Soc. B 2017 284 20171169; DOI: 10.1098/rspb.2017.1169.