Ex vivo recordings reveal desert locust forelimb control is asymmetric

Lateralized behaviours are widespread among the animals, including insects with their miniature brains, perhaps being a way of maximising neural capacity (reviewed in [1,2]). However, evidence for functional asymmetries in the neural circuitry itself is scarce. Here, using bilateral simultaneous recordings from the ex vivo nervous system of desert locusts, we show that the neural control of their forelimbs is asymmetric. This asymmetry was retained throughout the experimental period and either with or without the suboesophageal ganglion (SOG). These findings provide evidence for hard-wired neural sidedness and contribute to our understanding of the lateralization observed in in-vivo motor behaviours. Knebel et al. show that, in the desert locus motor output to the forelimbs is asymmetric in ex-vivo preparations of the ventral nerve cord. Such hard-wired asymmetry could underlie behavioural asymmetries in this species.