[
International Worm Meeting,
2021]
The nature of the relationship between neural circuits and the resulting animal behavior is a key question in neurobiology. It was previously established that the specific synaptic and cellular properties of neural networks can be widely disparate, yet maintain similar function (Prinz et al., 2004). It is therefore clear that some features of a network's structure are important to retain certain functional features. The sensitivity of such networks to changes in the topology have not been characterized. To explore the contribution of topology to the network's performance, we focused here on the circuit for nociceptive behaviors in C. elegans. The neurons of the circuit are shared between the two sexes, but their connectivity is different (Cook et al., 2019). The behaviors that result from these circuits are sexually dimorphic as well. The distinct network topologies and behavioral outputs make this circuit a good example for exploring the relationship between structure and function in neural networks. We simulated the response of the nociceptive circuits to external stimuli, in males and in hermaphrodites, using a wide range of realistic values for the circuit's biophysical parameters (synaptic strengths, conductivity, membrane time constants, etc.). We then searched for the parameters' space in which the activity of the motor output neurons in the simulation would match the worms' behaviors in experimental observations. We found an overlap between the sexes in terms of the synaptic and cellular parameters that allow for the correct behavior of the network. Moreover, our results suggest that the connectivity alone might be sufficient to explain the behavioral differences between the sexes. Notably, more stringent requirements of the models' performance suggests that the connections in this network cannot be all excitatory, as has been commonly assumed, or that additional inhibitory neurons must play an important role in shaping the circuit's response to tail stimulation. Future analysis will further explore the relations between the network's topology and the joint activity patterns of the neurons as measured by calcium imaging.