Skip to main content
Article thumbnail
Location of Repository

A Computational Analysis of the Gradient Navigation strategies of the Nematode Caenorhabditis elegans.

By Serge Thill


In the present thesis, we apply computational methods to the study of animal behaviour. Specifically, we are interested in the gradient navigation strategies of C. elegans, for which we show that there are many interesting questions that have not yet been answered by existing research.\ud In order to study the behaviour of C. elegans, we first develop a range of tools to help us do so. We base a large part of our work on Markov-like models of behaviour and since these are not Markovian in the strict sense (limiting the analytical tools which can be used to study their behaviour), we first present a possible transformation from a Markov-like model with variable transition probabilities\ud into a strictly Markovian model. We next present a framework for studying the behaviour of behavioural models which is not restricted to the work presented here but is likely to find general use in behavioural studies.\ud Using these tools, we then analyse the chemotactic behaviour of C. elegans, showing that we can adequately explain most features of this behaviour using energy-efficiency considerations. We also show that the main behavioural strategy, so-called pirouettes is likely to be caused by an inability to sample the environment during a turn and that the animal my not be acting upon gradient information while reversing.\ud Finally, we investigate the deterministic isotherm tracking strategy displayed by C. elegans. We develop a computational model for this behaviour which is able to reproduce all of the main features of C. elegans isotherm tracking and we propose a candidate neural circuit which might\ud encode this strategy. Additionally, we briefly discuss the use of stochastic strategies by the animal when moving towards its preferred temperature.\ud In summary, the work presented here therefore provides contributions to two major fields: we extend the methodology available for behavioural analysis in ethology and we contribute a number of insights and advancements to the field of C. elegans research

Publisher: University of Leicester
Year: 2008
OAI identifier:

Suggested articles


  1. (2005). A circuit for navigation in Caenorhabditis Bibliography 172 elegans. doi
  2. (2006). A diaclyglycerol kinase modulates long-term thermotactic behavioral plasticity in C. doi
  3. (2005). A dynamic body model of the nematode C. elegans with neural oscillators. doi
  4. (2005). A model of motor control of the nematode C. elegans with neuronal circuits. doi
  5. (2004). A neural network model of chemotaxis predicts functions of synaptic connections in the nematode Caenorhabditis elegans. doi
  6. (1952). A quantitative description of membrane current and its application to conduction and excitation in nerve. doi
  7. (1999). A subspace, interior, and conjugate gradient method for large-scale bound-constrained minimization problems. doi
  8. (1985). A thermodynamical approach to the travelling salesman problem: an efficient solution algorithm. doi
  9. (1998). Active currents regulate sensitivity and dynamic range in C. elegans neurons. doi
  10. (1968). An introduction to probability theory and its applications. doi
  11. (2005). Analysis of the effects of turning bias on chemotaxis in C. elegans. doi
  12. (2002). Antagonistic pathways in neurons exposed to body fluid regulate social feeding in Caenorhabditis elegans. doi
  13. (1987). Approximate solution of the trust region problem by minimization over two-dimensional subspaces. Mathematical Programming, doi
  14. (2001). C. elegans odour discrimination requires asymmetric diversity in olfactory neurons.
  15. (1991). Chemosensory neurons with overlapping functions direct chemotaxis to multiple chemicals in C. doi
  16. (1973). Chemotaxis by the nematode Caenorhabditis elegans: Identification of attractants and analysis of the response by use of mutants. doi
  17. (1972). Chemotaxis in Escherichia coli analysed by three-dimensional tracking. doi
  18. (2000). Computational Explorations in Cognitive Neuroscience. doi
  19. (1999). Computational rules for chemotaxis in the nematode C. doi
  20. (1970). Computer Models in Genetics. doi
  21. (2003). Database of synaptic connectivity of C. elegans for computation. Technical Report of CCeP, Keio Future 3,
  22. (2000). Dynamic Enerergy and Mass Budgets in Biological Systems. doi
  23. editors (2002-2005). Atlas of C. elegans anatomy - an illustrated handbook, chapter Hermaphrodite Anatomy.
  24. (1996). Eight potassium channel families revealed by the C. elegans genome project. doi
  25. (1990). Euler’s "exemplum memorabile inductionis fallacis" and q-trinomial coefficients. doi
  26. (2005). Experiencedependent modulation of C. elegans Behaviour by ambient oxygen. Current Biology, doi
  27. (2005). Flexible couplings: Diffusing neuromodulators and adaptive robotics. doi
  28. (2003). Functional mapping of neurons that control locomotory behavior in Caenorhabditis elegans. doi
  29. (1993). Genetic and cellular analysis of behavior doi
  30. (1999). Genetics of chemotaxis and thermotaxis in the nematode Caenorhabditis elegans. Annual Review of Genetics, doi
  31. (1996). Handbook of Ethological Methods. doi
  32. (2007). infotaxis’ as a strategy for searching without gradients. doi
  33. (1997). Introduction to Probability, chapter Markov Chains,
  34. (1899). La mue et l’enkystement chez les nématodes.
  35. (2003). Lim homeobox gene-dependent expression of biogenic anime receptors in restricted regions of the C. elegans nervous system. doi
  36. (1997). Machine Learning. doi
  37. (1999). Markov Chains, Gibbs Field, Monte Carlo Simulation and Queues. doi
  38. (1993). Measuring Behaviour. doi
  39. (1986). Mechanisms in Insect Olfaction, chapter Pheromone-modulated movements of flying moths,
  40. (1900). Modes et formes de reproduction des nématodes.
  41. (2003). Molecular approaches to aggregation behavior and social attachment. doi
  42. (1993). Motor neuron m3 controls pharyngeal muscle relaxation timing in Caenorhabditis elegans.
  43. (1998). Natural variation in a neuropeptide y receptor homolog modifies social behavior and food response in C. doi
  44. (2007). Neural circuits mediate electrosensory behavior in Caenorhabditis elegans. doi
  45. (1995). Neural regulation of thermotaxis in Caenorhabditis elegans. doi
  46. (2005). Neuronal substrates of complex behaviors doi
  47. (2002). Olfactory search at high reynolds number. doi
  48. (1963). On aims and methods of ethology. Zeitschrift für Tierpsychologie, doi
  49. (1966). On optimal use of a patchy environment. doi
  50. (1983). Optimization by simulated annealing. doi
  51. (2004). Oxygen sensation and social feeding mediated by a C. elegans guanylate cyclase homologue. doi
  52. (2004). Parameter optimization technique using the response surface methodology. doi
  53. (1935). Pharmacology and nerve endings. doi
  54. (2006). Prediction of the behavioural strategy in a chemotaxis search task.
  55. (2006). Quantitative analysis of thermotaxis in the nematode Caenorhabditis elegans. doi
  56. (1994). Reiterative responses to single strands of odor promote sustained upwind flight and odor source location by moths. doi
  57. (2003). Reversal frequency in Caenorhabditis elegans represents an integrated response to the state of the animal and its environment.
  58. (2007). Sensorimotor control during isothermal tracking in Caenorhabditis elegans. doi
  59. (1996). Sensory signaling in Caenorhabditis elegans. Current Opinion In doi
  60. (2001). Serotonin modulates locomotory behavior and coordinates egg-laying and movement in Caenorhabditis elegans. doi
  61. (2007). Short-term adaptation and temporal processing in the cryophilic response of Caenorhabditis elegans. doi
  62. (2004). Similar network activity from disparate circuit parameters. doi
  63. (2005). Simulated diffusion of phosphorylated chey through the cytoplasm of Escherichia coli. doi
  64. (2002). Single ionic channels of two Caenorhabditis elegans chemosensory neurons in native membrane. doi
  65. (2002). Smallest small-world network. Physical Review E, doi
  66. (2002). Social feeding in Caenorhabditis elegans is induced by neurons that detect aversive stimuli. doi
  67. (2004). Soluble guanylate cyclases act in neurons exposed to the body fluid to promote C. elegans aggregation behavior. doi
  68. (2004). Specification of chemosensory neuron subtype identities in Caenorhabditis elegans. Current Opinion In doi
  69. (2003). Step response analysis of thermotaxis in Caenorhabditis elegans.
  70. (2005). Step-response analysis of chemotaxis in Caenorhabditis elegans.
  71. (2004). Stochastic formulation for a partial neural circuit of C. doi
  72. (1987). Studies on the Development and Organisation of the Nervous System of Caenorhabditis Elegans.
  73. (2003). Synaptic activity of the afd neuron in Caenorhabditis elegans correlates with thermotactic memory. doi
  74. (1952). Systematik und phylogenie der gattung rhabditis (nematoda). Zoologische Jahrbücher (Abteilung Systematik), doi
  75. (1953). Thaper Commemoration Volume,, chapter The genera of the subfamily Rhabditinae Micoletzky,
  76. (2006). The afd sensory neurons encode multiple functions underlying thermotactic behavior in Caenorhabditis elegans. doi
  77. (2004). The C. elegans thermosensory neuron afd responds to warming. Current Biology, doi
  78. (2007). The chemotactic behavior of computer-based surrogate bacteria. Current Biology, doi
  79. (2007). The ecology of action selection: Insights from artificial life. doi
  80. (1999). The fundamental role of pirouettes in Caenorhabditis elegans chemotaxis.
  81. (2004). The gaba nervous system in C. Elegans. Trends In doi
  82. (1949). The Mathematical Theory of Communication. doi
  83. (1985). The neural circuit for touch sensitivity in Caenorhabditis elegans.
  84. (1986). The structure of the nervous system of the neamtode C. elegans. doi
  85. (1993). Theory of continuum random walks and application to chemotaxis. Physical Review E, doi
  86. (1993). Theory of the locomotion of nematodes: Control of the somatic motor neurons by interneurons. doi
  87. (2002). Thermotaxis in Caenorhabditis elegans analyzed by measuring responses to defined thermal stimuli.
  88. (2001). Topology of gap junction networks in C. doi
  89. (2007). Understanding complex behaviors by analyzing optimized models: C. elegans gradient navigation. doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.