NEST Conference 2025

Adult Neurogenesis in the Dentate Gyrus

T-1

17 Jun 2025, 10:00

20m

Zoom

Talk Talks

Speaker

Aadhar Sharma (Bernstein Center Freiburg, University of Freiburg)

Description

As a rule, no new neurons are born in the adult mammalian brain. As an exception, however, adult neurogenesis is readily observed in niches such as the dentate gyrus where neuronal precursors are transformed into granule cells. Dentate granule cells constitute a major population of principal cells in the trisynaptic circuit and are implicated in hippocampal functions such as pattern separation. Newborn granule cells exhibit distinctive properties that, as they mature, progressively converge toward those of pre-established mature granule cells. While it has been suspected that the age-dependent properties of adult-born cells contribute to their integration into the network, it is not known how exactly the integration dynamics and hippocampal function are affected by it.

We have developed models where adult-born granule cells undergo experimentally-matched maturation, forming new connections within the pre-existing networks. Our findings suggest that the age-dependent properties are critical for network integration. Analysis suggests that, if large numbers of cells are rapidly added, pathological states resembling epilepsy may emerge. Studying different network configurations further indicates that adult-born neurons compete for synaptic resources with mature ones, consistent with the experimental observation that perforant pathway synapses are redistributed between newborn and mature cells.

Our models provide a promising tool to study the dynamics of adult neurogenesis and how it might affect hippocampal computations. In the talk, I will provide an overview of our modelling approach, and briefly summarise our preliminary results. I will also share the details about our latest model and the practical challenges involved with it.

References

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