Ultimate and proximate aspects of spatial learning in an individually foraging social insect

• Applicant: Professorin Dr. Susanne Foitzik, since 1/2023
• Subject Area: Sensory and Behavioural Biology ; Evolution, Anthropology
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 453687543

Learning, the process of altering one’s behaviour following experience, is a common process animals undergo. Learning can increase the performance of various activities and consequently an animals’ fitness. This multidisciplinary proposal focuses on the triple link between learning, forgetting and gene expression, a rarely studied combination. We do so in the context of foraging behaviour. Learning is expected while foraging, because animals regularly search for food and need to adjust their behaviour. We have identified gaps in the current literature, which we plan to fill by studying: (1) the proximate molecular mechanisms that underlie learning processes; (2) forgetting, in particular, the adaptive loss of information, which can be as important as learning but is less often studied; and (3) the adaptive value of spatial learning under competitive conditions. Although competition drives many ecological and evolutionary processes, the value of learning has not been tested under competitive conditions in naive individuals. We propose to explore all these aspects in an individually foraging ant, Cataglyphis niger. We have shown that C. niger workers learn to solve a maze and remember this spatial information for over two weeks. Moreover, we used transcriptomics and epigenetic inhibitors intensely to investigate gene expression and gene regulatory processes underlying different behaviours in ants. We propose here a series of experiments to analyse (1) which changes in gene expression, histone modifications and DNA methylation are associated with learning and forgetting. We expect that inhibiting relevant epigenetic processes will impair learning and may lead to faster forgetting. (2) The behavioural mechanism of forgetting, whether it is a passive process (decay), or an active one, involving either retroactive or proactive interferences, i.e., either that learning new information could interfere with memory, or that prior information interferes with acquiring new information. We combine a lab with a field experiment, to test whether learning and forgetting also yields fitness benefits in nature (3) The interactive effect of colony size and learning on foraging success under competition conditions. We predict that smaller colonies can outcompete larger ones, given superior learning ability of workers and spatial information where to find the food resources. Our findings will to be of interest to researchers from various fields – from behavioural ecology, through experimental psychology to molecular neurobiology. The behavioural experiments will be carried out by the Israeli PI, while the genomic and bioinformatic analyses will be conducted by PIs in Germany. The plan therefore offers an effective cooperative framework, complementing each other’s expertise. All PIs are experienced social insect researchers with expertize required for the project and they have already demonstrated their ability to work well together.

• DFG Programme: Research Grants
• International Connection: Israel
• International Co-Applicant: Professor Dr. Inon Scharf
• Ehemaliger Antragsteller: Dr. Romain Libbrecht, Ph.D., until 1/2023