Neuronal correlates of social behavior - an electrophysiological study on fighting crickets

• Applicant: Jan Rillich, Ph.D.
• Subject Area: Cognitive, Systems and Behavioural Neurobiology
• Term: from 2016 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 321076726

Little is known about the underlying mechanisms followed by complex neuronal circuits to generate adaptive social behavior. The main objective of the proposed project is to unravel cellular correlates for experience dependent plasticity in aggression of crickets. I want to record response properties of neurons of these social insects during different decision making processes and after various social experiences. To achieve this I will make long term (days), chronic extracellular multi-unit recordings from neurons in the brains of freely behaving and interacting crickets using a newly established technique and wherever possible combine this with chronic recordings from muscles, nerves and ganglion connectives using conventional techniques, and video recordings of ongoing activity. These results of this study will lead to an understanding of how different social experiences (e.g. winning, losing) and resultant behavioral states (aggressive/ submissive) influence neuronal processing in the brain and thereby the expression of aggression. Cricket aggression constitutes an ideal model system for studying neural correlates of social behavior. Crickets escalate in a very stereotyped manner. They make adaptive behavioral decisions by exploiting the power of neuromodulation and the degree of their aggressive expression can be fine tuned by antennal and cercal stimulations. The two main objectives of this project are to unravel where, how and under which experience-dependent conditions neurons control aggressive motor performances and to elucidate where and how sensory inputs from opponents are processed. Basically three key brain centers can be considered as being involved in the control of insect aggression, antennal neuropils, the central complex and the mushroom bodies. Antennal neuropil is the first relay station for eliciting aggression and the central complex and the mushroom bodies are brain areas that are known to control motor output and to process sensory inputs. To identify the role of neuronal activity I will compare multi-unit brain recordings during natural fights with neuronal responses to antennal and cercal stimulation. Using this approach I aim to explore the roles of specific brain centers in initiating, tuning, maintaining and terminating aggressive behavior at the cellular level. I anticipate that the application of combined behavioral, pharmacological and electrophysiological techniques will provide completely new insights into how aggression is controlled at the cellular level.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Paul Anthony Stevenson