Vivek H Sridhar (University of Konstanz): title tba
September 14, 2023, 3 PM, Old lecture Hall, German Primate Center

Jenny Tung (Max Planck Institute of Evolutionary Anthropology Leipzig): Mothers, molecules and mortality: the imprint of social relationships across teh life course in wild baboons
Jun 8, 2023, 3 PM, Michael Lankeit Lecture Hall, German Primate Center

Field studies of natural primate populations present a powerful opportunity to investigate the social and ecological determinants of health and fitness using fine-grained observations of known individuals across the life course. Here, I will summarize our emerging understanding of this process in the wild baboons of the Amboseli ecosystem in Kenya, emphasizing the insights provided by integrating behavioral and molecular data. I will review the strong evidence that early life adversity, social status, and affiliative ties in adulthood are central to life outcomes. I will then discuss how, by integrating genomic methods with longitudinal behavioral observations, we have been able to identify sex-specific signatures of social interactions and evidence for biological embedding via changes in DNA methylation. Together, our findings connect classical life course perspectives on primate behavior and life history with changes in gene regulation “under the skin.” They thus illustrate the increasing potential to understand our study subjects at both the whole-organism and molecular levels, even under field conditions.

Elad Schneidman (Weizmann Institute of Science): Architectural design principles of neural circuits
Jun 1, 2023, 3 PM, Old lecture Hall, German Primate Center

The map of synaptic connectivity among neurons in the brain shapes the computations that neural circuits may perform. Inferring the design principles of neural connectomes is, therefore, fundamental for understanding brain development and architecture, neural computations, learning, and behavior. We learn probabilistic generative models for the connectomes of the olfactory bulb of zebrafish, part of the mouse visual cortex, and of C. elegans. We show that in all cases, models that rely on a surprisingly small number of simple biological and physical features accurately predict the existence of individual synapses and their strength, distributions of synaptic indegree and outdegree of the neurons, frequency of sub-network motifs, and more. Furthermore, we simulate synthetic circuits generated by our model and show that they replicate the computation that the real circuit performs. Thus, our results reflect surprisingly simple design principles of real connectomes. We then explore the architectural features that may shape the computation that connectomes may carry. We measure the similarity of simulated spiking neural networks of neurons in terms of their response to different stimuli, and learn a functional metric between networks based on their synaptic differences. We show that unlike common graph theory tools, our metric accurately predicts the similarity of novel networks, relying on a sparse set of architectural features. We then identify potential key architectural features that control the computations that particular connectomes may implement.

SFB Theory Days
May 31st/June 1st, 2023, seminar rooms, German Primate Center

Brandon Munn (U Sydney): Neuronal modelling bridges macroscale adaptive signatures across arousal
May 16, 2023, 3 PM, Michael Lankeit Lecture Hall, German Primate Center

The human brain displays a rich repertoire of states that emerge from the microscopic interactions of cortical and subcortical neurons. Unfortunately, difficulties inherent within large-scale simultaneous neuronal recording limit our ability to link biophysical processes at the microscale to emergent macroscopic brain states. Here we introduce a microscale biophysical network model of layer-5 pyramidal neurons that display graded coarse-sampled dynamics matching those observed in macroscale electrophysiological recordings from macaques and humans. We invert our model to identify the neuronal spike and burst dynamics that differentiate unconscious, dreaming, and awake arousal states and provide novel insights into their functional signatures. We further show that neuromodulatory arousal can mediate different modes of neuronal dynamics around a low-dimensional energy landscape, which in turn changes the response of the model to external stimuli. Our results highlight the promise of multiscale modelling to bridge theories of consciousness across spatiotemporal scales.