Kavli Affiliate: Samuel Pfaff
| Authors: Remi Ronzano, Sophie Skarlatou, Bianca K Barriga, B. Anne Bannatyne, Gardave Singh Bhumbra, Joshua David Foster, Jeffrey Moore, Camille Lancelin, Amanda Pocratsky, Mustafa Gorkem Ozyurt, Calvin Chad Smith, Andrew J. Todd, David J. Maxwell, Andrew J. Murray, Samuel L Pfaff, Robert M. Brownstone, Niccolo’ Zampieri and Marco Beato
| Summary:
Abstract Elaborate behaviours are produced by tightly controlled flexor-extensor motor neuron activation patterns. Motor neurons are regulated by a network of interneurons within the spinal cord, but the computational processes involved in motor control are not fully understood. The neuroanatomical arrangement of motor and premotor neurons into topographic patterns related to their controlled muscles is thought to facilitate how information is processed by spinal circuits. Rabies retrograde monosynaptic tracing has been used to label premotor interneurons innervating specific motor neuron pools, with previous studies reporting topographic mediolateral positional biases in flexor and extensor premotor interneurons. To more precisely define how premotor interneurons contacting specific motor pools are organized we used multiple complementary viral-tracing approaches to minimize systematic biases associated with each method. Contrary to expectations, we found that premotor interneurons contacting different motor pools are highly intermingled rather than segregated into specific domains like motoneurons. Thus, premotor spinal neurons controlling different muscles process motor instructions in the absence of clear spatial patterns among the flexor-extensor circuit components. Competing Interest Statement RMB is a co-founder of Sania Therapeutics, Inc and consults for Sania Rx Ltd