Some recent developments in 2018 and 2019
We are currently gathering developmental data across a broad range of species, and we hope to use these data to update the translating time project in the coming years. Most of this work is spearheaded by Dr. Christine Charvet at Delaware State University. Here are some recent works that build from the translating time data-set. These works focus on understanding how similar or different we are from other species:
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.
Integrating neuroimaging with gene expression data to tackle the evolution and development of connections in the human lineage:
Share your data with us!
If you have developmental data on one or a number of species and would like to share or collaborate, please contact Christine Charvet at the following email address: charvetcj(at)gmail.com.