Universität zu Köln

Sakagiannis, Panagiotis ORCID: 0000-0002-1033-5387 (2025). Holistic behavioral modeling: A case study on Drosophila larva foraging. PhD thesis, Universität zu Köln.

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Abstract

This thesis presents the Behavioral Architecture - Dynamic Energy Budget (BA-DEB) framework, a holistic computational approach to behavioral modeling grounded in four core commitments: (i) agent-centered modeling, where the organism is treated as an internally structured and environmentally embedded unit; (ii) comprehensive behavioral scope, instantiated in a modular, hierarchical BA that spans from motor primitives to experience-shaped adaptivity; (iii) cross-timescale integration of neural, behavioral, and metabolic processes; and (iv) homeostatic regulation, achieved through the coupling of the BA with a DEB model that simulates internal energetics and shapes behavior through metabolic feedback. These principles are exemplified in a case study of foraging behavior in the Drosophila melanogaster larva – a model organism with a tractable nervous system, rich behavioral repertoire and readily recordable 2D posture – engaged in a well-characterized, structured behavior during a normatively narrow life stage focused on growth and survival. Standalone mechanistic models form a second core contribution of this thesis. These include a stochastic network model of behavioral intermittency and a coupled-oscillator model that captures the biomechanical interference of crawling on lateral bending. These models formalize biologically plausible mechanistic hypotheses and can be integrated into the BA as modular components, reflecting the framework’s capacity to accommodate diverse behavioral mechanisms within a unified control structure. The BA-DEB framework is implemented in Larvaworld, an open-source simulation and analysis platform that generates realistic behavior by combining mechanistic modeling with data-driven fitting. It facilitates exploratory modeling via unbiased empirical validation, and interdisciplinary collaboration through standardized behavioral modules and flexible experimental configurations. Together, the framework and software platform provide a robust and extensible, conceptual and methodological foundation for building, testing, and comparing models of behavior grounded in biological detail and organized in a behavior-based modular logic.

Item Type:	Thesis (PhD thesis)
Creators:	Creators Email ORCID ORCID Put Code Sakagiannis, Panagiotis p.sakagiannis@uni-koeln.de https://orcid.org/0000-0002-1033-5387 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-792102
Date:	2025
Place of Publication:	Köln
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Biology > Zoologisches Institut
Subjects:	Natural sciences and mathematics Life sciences
Uncontrolled Keywords:	Keywords Language Drosophila larva English Dynamic Energy Budget English behavioral modeling English foraging English behavioral intermittency English
Date of oral exam:	6 October 2025
Referee:	Name Academic Title Nawrot, Martin Paul Prof. Dr. Büschges, Ansgar Prof. Dr. Thum, Andreas Stephan Prof. Dr.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/79210