Loss of ETV1/ER81 in motor neurons leads to reduced monosynaptic inputs from proprioceptive sensory neurons

article Loss of ETV1/ER81 in motor neurons leads to reduced monosynaptic inputs from proprioceptive sensory neurons published yes David R. Ladle author Simon Hippenmeyer author 37B36620-F248-11E8-B48F-1D18A9856A870000-0003-2279-1061 SiHi department Presynaptic inputs determine the pattern of activation of postsynaptic neurons in a neural circuit. Molecular and genetic pathways that regulate the selective formation of subsets of presynaptic inputs are largely unknown, despite significant understanding of the general process of synaptogenesis. In this study, we have begun to identify such factors using the spinal monosynaptic stretch reflex circuit as a model system. In this neuronal circuit, Ia proprioceptive afferents establish monosynaptic connections with spinal motor neurons that project to the same muscle (termed homonymous connections) or muscles with related or synergistic function. However, monosynaptic connections are not formed with motor neurons innervating muscles with antagonistic functions. The ETS transcription factor ER81 (also known as ETV1) is expressed by all proprioceptive afferents, but only a small set of motor neuron pools in the lumbar spinal cord of the mouse. Here we use conditional mouse genetic techniques to eliminate Er81 expression selectively from motor neurons. We find that ablation of Er81 in motor neurons reduces synaptic inputs from proprioceptive afferents conveying information from homonymous and synergistic muscles, with no change observed in the connectivity pattern from antagonistic proprioceptive afferents. In summary, these findings suggest a role for ER81 in defined motor neuron pools to control the assembly of specific presynaptic inputs and thereby influence the profile of activation of these motor neurons. American Physiological Society2023 eng PhysiologyGeneral Neuroscience Journal of Neurophysiology 0022-3077 1522-1598 36695533 00095772160000110.1152/jn.00172.2022 1293501-512 D.R. Ladle, S. Hippenmeyer, Journal of Neurophysiology 129 (2023) 501–512. Ladle, D. R., & Hippenmeyer, S. (2023). Loss of ETV1/ER81 in motor neurons leads to reduced monosynaptic inputs from proprioceptive sensory neurons. Journal of Neurophysiology. American Physiological Society. <a href="https://doi.org/10.1152/jn.00172.2022">https://doi.org/10.1152/jn.00172.2022</a> Ladle DR, Hippenmeyer S. 2023. Loss of ETV1/ER81 in motor neurons leads to reduced monosynaptic inputs from proprioceptive sensory neurons. Journal of Neurophysiology. 129(3), 501–512. D. R. Ladle and S. Hippenmeyer, “Loss of ETV1/ER81 in motor neurons leads to reduced monosynaptic inputs from proprioceptive sensory neurons,” Journal of Neurophysiology, vol. 129, no. 3. American Physiological Society, pp. 501–512, 2023. Ladle, David R., and Simon Hippenmeyer. “Loss of ETV1/ER81 in Motor Neurons Leads to Reduced Monosynaptic Inputs from Proprioceptive Sensory Neurons.” Journal of Neurophysiology. American Physiological Society, 2023. <a href="https://doi.org/10.1152/jn.00172.2022">https://doi.org/10.1152/jn.00172.2022</a>. Ladle, David R., and Simon Hippenmeyer. “Loss of ETV1/ER81 in Motor Neurons Leads to Reduced Monosynaptic Inputs from Proprioceptive Sensory Neurons.” Journal of Neurophysiology, vol. 129, no. 3, American Physiological Society, 2023, pp. 501–12, doi:<a href="https://doi.org/10.1152/jn.00172.2022">10.1152/jn.00172.2022</a>. Ladle DR, Hippenmeyer S. Loss of ETV1/ER81 in motor neurons leads to reduced monosynaptic inputs from proprioceptive sensory neurons. Journal of Neurophysiology. 2023;129(3):501-512. doi:<a href="https://doi.org/10.1152/jn.00172.2022">10.1152/jn.00172.2022</a> 125622023-02-15T14:46:14Z2024-10-21T06:01:28Z