Contribution of the anterior lateral motor cortex to predictive postural control in rats

Predictive postural control is a motor function that enables animals to manage expected mechanical disturbances. The rodent anterior lateral motor cortex (ALM) may contribute to this function through interactions with the cerebellum; however, the underlying cortical mechanisms remain unclear. Here, we examined whether the ALM contributes to the emergence of experience-dependent improvements in predictive postural control in a rat platform-tilt paradigm. Rats received bilateral muscimol injections into the ALM (muscimol group) or vehicle injections (vehicle group) before completing sixty conditioned platform-tilting trials. The initial upright posture and reactive responses to the disturbances did not differ between groups. However, both segmental kinematics and regression-based analyses of the center-of-mass angle revealed that experience-dependent reduction in postural response, which is consistent with the acquisition of predictive postural control, was attenuated in the muscimol group. Furthermore, unlike the control, the muscimol group did not develop forward shank inclination, which is a preparatory adjustment to counteract the upcoming disturbance. These results indicate that ALM activity plays an important role in the emergence of experience-dependent improvements in predictive postural control, while exerting little effect on baseline standing. Our findings highlight the role of ALM in feedforward regulation of posture and motivate future investigations into broader networks.