RT Journal Article SR Electronic T1 Activity of Red Nucleus Neurons in the Cat during Postural Corrections JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 14533 OP 14542 DO 10.1523/JNEUROSCI.2991-10.2010 VO 30 IS 43 A1 Pavel V. Zelenin A1 Irina N. Beloozerova A1 Mikhail G. Sirota A1 Grigori N. Orlovsky A1 Tatiana G. Deliagina YR 2010 UL http://www.jneurosci.org/content/30/43/14533.abstract AB The dorsal-side-up body posture in standing quadrupeds is maintained by the postural system, which includes spinal and supraspinal mechanisms driven by somatosensory inputs from the limbs. A number of descending tracts can transmit supraspinal commands for postural corrections. The first aim of this study was to understand whether the rubrospinal tract participates in their transmission. We recorded activity of red nucleus neurons (RNNs) in the cat maintaining balance on the periodically tilting platform. Most neurons were identified as rubrospinal ones. It was found that many RNNs were profoundly modulated by tilts, suggesting that they transmit postural commands. The second aim of this study was to examine the contribution of sensory inputs from individual limbs to posture-related RNN modulation. Each RNN was recorded during standing on all four limbs, as well as when two or three limbs were lifted from the platform and could not signal platform displacements. By comparing RNN responses in different tests, we found that the amplitude and phase of responses in the majority of RNNs were determined primarily by sensory input from the corresponding (fore or hind) contralateral limb, whereas inputs from other limbs made a much smaller contribution to RNN modulation. These findings suggest that the rubrospinal system is primarily involved in the intralimb postural coordination, i.e., in the feedback control of the corresponding limb and, to a lesser extent, in the interlimb coordination. This study provides a new insight into the formation of supraspinal motor commands for postural corrections.