Manipulation of neuron transmission in the mushroom bodies and protocerebral bridge affects social behaviour
Authors: Abigail Bechard; J. Wesley Robinson; Ryley Yost; Anne Simon
Affiliation: Western University, London ON, Canada
Keywords: r. circuits; c. models of ASD
Social interactions between animals depend upon where they settle in relation to each other; a behaviour called social spacing. This behaviour is defined as the distance between individuals in a stable group and has been shown to be affected by life experience, genetics, and the environment. Simple interactions like social spacing that mediate and precede more complex behaviours serve as a practical means to elucidate the basic neurogenetics involved in a variety of social behaviours.
Social behaviours are determined by perceiving attractive and repulsive cues from other individuals, followed by the neural integration of these cues. A key aspect in the determination of an organism's behaviour (including social spacing) is how these cues are integrated in the brain. For example, in D. melanogaster the Mushroom Bodies (MB) have been demonstrated to be involved in specific behaviours like temperature preference, social approach, and food-seeking, as well as learning, and memory.
Here, we are interested in elucidating the neural circuitry which modulates social spacing at the level of brain structures. We are currently investigating whether two brain structures, the Mushroom Bodies and the Protocerebral Bridge (PB), play a role in social spacing neural circuitry. These structures are of interest because they show enrichment of Neuroligin-3 (Nlg-3), a postsynaptic cell adhesion protein that we previously found to have a strong association with social spacing behaviour.
Using the Gal4/UAS system in combination with social spacing assays, we quantified the behavioural response of flies when hyperactivating or silencing neuron transmission in the MB, PB, or both simultaneously. Thus far we have found that hyperactivating the MB causes flies of both sexes to group more closely together. We will share our hypotheses for the neurogenetic interaction between Nlg-3 and the neural circuitry which modulates social space as well as the effects of silencing neuronal transmission in the PB.