The Charvet laboratory at Auburn University (www.charvetlab.com) is focused on integrating high-through-put methods in neuroimaging and sequencing to translate time across species and to develop new tools to better study connections in health and in disease. Cutting across scales of organization will enhance our ability to study pathways of the human brain and bridge the gap between model systems and humans with enhanced translational tools.
Here are some recent studies:
Translating time across the lifespan in humans and chimpanzees:
A recent study integrates temporal variation in transcription, behavior, and anatomy 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!
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. BioRxiv.
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. Here is the paper:
Co-evolution in the timing of cell type maturation in the human lineage:
How do cell types evolve? Well, there are two major cell types (i.e., GABAergic, pyramidal neurons) in our cortex (the wrinkly outer surface of the brain). These two major cell types are generated from two spatially distinct zones during development. We use the translating time data-set and incorporate additional data on the timing of developmental transformations to show that the production of GABAergic and pyramidal neuron maturation is extended in primates relative to rodents. These findings explain why primates (Including humans) have more GABAergic and pyramidal neurons compared with rodents in adulthood. Extending the duration of cell production has major implications for how brain processes information. Here is the paper:
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.