Analysis of neural amygdalo-hippocampal cell turnover dynamics using 15N-Thymidine-based multi-isotope mass spectrometry in humans

• Applicant: Professor Dr. Hagen Bernhard Huttner
• Subject Area: Molecular and Cellular Neurology and Neuropathology ; Molecular Biology and Physiology of Neurons and Glial Cells
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 549480243

One of the key questions in neuroscience is to what extent the generation of new cells, especially that of neurons (i.e. neurogenesis), contributes to the plasticity of the central nervous system (CNS) of adult humans under physiological conditions. Closely related to this is the question whether the generation of new neurons in the CNS is induced in response to neurological disease, as well as the issue of the potential functional relevance of such neurogenesis. Although there are many animal studies on this topic, the situation in humans is far less clear. In particular, standard methods used in animal experiments such as DNA synthesis labeling using BrdU cannot be used in humans due to toxicity. The present research proposal aims at using a methodology that has been established by the applicant for the first time for the CNS. Using the so-called 15N-thymidine infusion methodology, our knowledge about neural cell generation in both the healthy and the diseased human CNS can be enormously improved. Specifically, in humans, an infusion of synthetically produced – and, in contrast to BrdU, non-toxic – 15N-thymidine stably marks the DNA of cells in the process of division in vivo. After clinically indicated surgical intervention, the brain tissue obtained is analyzed for the presence of 15N-positive cells using multiple isotope imaging mass spectrometry. Cells that had synthesized DNA in the process of their division during the infusion period, as well as their daughter cells, can be identified using this techique. With this new 15N-thymidine methodology, it is proposed to quantify the mitotically active stem and progenitor cells as well as their postmitotic neuronal daughter cells in the hippocampus, both in the physiological situation and in neurological diseases. Using this approach, it should be possible to determine the extent of hippocampal neurogenesis in humans as well as to verify a possible neurogenesis in the human amygdala. In addition to these studies, the so-called "dormant progenitors", which have arrested their cell cycle and of which very little is known so far, will be quantified for the first time in these brain regions using 14C-radiocarbon dating. The present research proposal in essence is a 2 to the power of 4 approach: 2 methods (15N-thymidine and 14C-radiocarbon methodology), 2 regions (hippocampus and amygdala), 2 cell types (stem/progenitor cells and neurons), 2 conditions (physiological and pathological).

• DFG Programme: Research Grants