02599nas a2200289   4500008004100000022001400041245013200055210006900187260001200256300001800268490000700286520174900293653001702042653002102059653001502080653001102095653001702106653001602123100001302139700001302152700001302165700001702178700002402195700002102219700002102240856004802261       2010                        eng d  a1529-240100aH-reflex up-conditioning encourages recovery of EMG activity and H-reflexes after sciatic nerve transection and repair in rats.0 aHreflex upconditioning encourages recovery of EMG activity and H  c12/2010  a16128–161360 v303 aOperant conditioning of the spinal stretch reflex or its electrical analog, the H-reflex, produces spinal cord plasticity and can thereby affect motoneuron responses to primary afferent input. To explore whether this conditioning can affect the functional outcome after peripheral nerve injury, we assessed the effect of up-conditioning soleus (SOL) H-reflex on SOL and tibialis anterior (TA) function after sciatic nerve transection and repair. Sprague Dawley rats were implanted with EMG electrodes in SOL and TA and stimulating cuffs on the posterior tibial nerve. After control data collection, the sciatic nerve was transected and repaired and the rat was exposed for 120 d to continued control data collection (TC rats) or SOL H-reflex up-conditioning (TU rats). At the end of data collection, motoneurons that had reinnervated SOL and TA were labeled retrogradely. Putative primary afferent terminals [i.e., terminals containing vesicular glutamate transporter-1 (VGLUT1)] on SOL motoneurons were studied immunohistochemically. SOL (and probably TA) background EMG activity recovered faster in TU rats than in TC rats, and the final recovered SOL H-reflex was significantly larger in TU than in TC rats. TU and TC rats had significantly fewer labeled motoneurons and higher proportions of double-labeled motoneurons than untransected rats. VGLUT1 terminals were significantly more numerous on SOL motoneurons of TU than TC rats. Combined with the larger H-reflexes in TU rats, this anatomical finding supports the hypothesis that SOL H-reflex up-conditioning strengthened primary afferent reinnervation of SOL motoneurons. These results suggest that H-reflex up-conditioning may improve functional recovery after nerve injury and repair.10aconditioning10aperipheral nerve10aplasticity10aReflex10aregeneration10aSpinal Cord1 aChen, Yi1 aWang, Yu1 aChen, Lu1 aSun, Chenyou1 aEnglish, Arthur, W.1 aWolpaw, Jonathan1 aChen, Xiang Yang  uhttp://www.ncbi.nlm.nih.gov/pubmed/2112355902091nas a2200253   4500008004100000022001400041245004000055210003800095260001200133300001400145490000800159520142300167653002101590653002101611653002501632653001701657653001101674653001601685100002301701700002301724700002101747700002101768856004801789       2006                        eng d  a0014-481900aDiurnal H-reflex variation in mice.0 aDiurnal Hreflex variation in mice  c01/2006  a517–5280 v1683 aMice exhibit diurnal variation in complex motor behaviors, but little is known about diurnal variation in simple spinally mediated functions. This study describes diurnal variation in the H-reflex (HR), a wholly spinal and largely monosynaptic reflex. Six mice were implanted with tibial nerve cuff electrodes and electrodes in the soleus and gastrocnemius muscles, for recording of ongoing and nerve-evoked electromyographic activity (EMG). Stimulation and recording were under computer control 24 h/day. During a 10-day recording period, HR amplitude varied throughout the day, usually being larger in the dark than in the light. This diurnal HR variation could not be attributed solely to differences in the net ongoing level of descending and segmental excitation to the spinal cord or stimulus intensity. HRs were larger in the dark than in the light even after restricting the evoked responses to subsets of trials having similar ongoing EMG and M-responses. The diurnal variation in the HR was out of phase with that reported previously for rats, but was in phase with that observed in monkeys. These data, supported by those in other species, suggest that the supraspinal control of the excitability of the HR pathway varies throughout the day in a species-specific pattern. This variation should be taken into account in experimental and clinical studies of spinal reflexes recorded at different times of day.10acircadian rhythm10aElectromyography10aimplanted electrodes10aMonosynaptic10aReflex10aSpinal Cord1 aCarp, Jonathan, S.1 aTennissen, Ann, M.1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1615178102210nas a2200205   4500008004100000022001400041245007200055210006900127260001200196300001600208490000700224520163400231653001101865653001201876100002101888700001301909700001301922700002101935856004801956       2006                        eng d  a0022-307700aOperant conditioning of reciprocal inhibition in rat soleus muscle.0 aOperant conditioning of reciprocal inhibition in rat soleus musc  c10/2006  a2144–21500 v963 aOperant conditioning of the H-reflex, the electrical analog of the spinal stretch reflex (SSR), induces activity-dependent plasticity in the spinal cord and might be used to improve locomotion after spinal cord injury. To further assess the potential clinical significance of spinal reflex conditioning, this study asks whether another well-defined spinal reflex pathway, the disynaptic pathway underlying reciprocal inhibition (RI), can also be operantly conditioned. Sprague-Dawley rats were implanted with electromyographic (EMG) electrodes in right soleus (SOL) and tibialis anterior (TA) muscles and a stimulating cuff on the common peroneal (CP) nerve. When background EMG in both muscles remained in defined ranges, CP stimulation elicited the TA H-reflex and SOL RI. After collection of control data for 20 days, each rat was exposed for 50 days to up-conditioning (RIup mode) or down-conditioning (RIdown mode) in which food reward occurred if SOL RI evoked by CP stimulation was more (RIup mode) or less (RIdown mode) than a criterion. TA and SOL background EMG and TA M response remained stable. In every rat, RI conditioning was successful (i.e., change > or =20% in the correct direction). In the RIup rats, final SOL RI averaged 171+/- 28% (mean +/- SE) of control, and final TA H-reflex averaged 114 +/- 14%. In the RIdown rats, final SOL RI averaged 37 +/- 13% of control, and final TA H-reflex averaged 60 +/- 18%. Final SOL RI and TA H-reflex sizes were significantly correlated. Thus like the SSR and the H-reflex, RI can be operantly conditioned; and conditioning one reflex can affect another reflex as well.10aReflex10aStretch1 aChen, Xiang Yang1 aChen, Lu1 aChen, Yi1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1680735102084nas a2200181   4500008004100000022001400041245007900055210006900134260001200203300001400215490000700229520154400236653001101780653002101791100002101812700002101833856004801854       2005                        eng d  a1072-050200aAblation of cerebellar nuclei prevents H-reflex down-conditioning in rats.0 aAblation of cerebellar nuclei prevents Hreflex downconditioning   c05/2005  a248–2540 v123 aWhile studies of cerebellar involvement in learning and memory have described plasticity within the cerebellum, its role in acquisition of plasticity elsewhere in the CNS is largely unexplored. This study set out to determine whether the cerebellum is needed for acquisition of the spinal cord plasticity that underlies operantly conditioned decrease in the H-reflex, the electrical analog of the spinal stretch reflex. Rats in which the cerebellar output nuclei dentate and interpositus (DIN) had been ablated were exposed for 50 d to the H-reflex down-conditioning protocol. DIN ablation, which in itself had no significant long-term effect on H-reflex size, entirely prevented acquisition of a smaller H-reflex. Since previous studies show that corticospinal tract (CST) transection also prevents down-conditioning while transection of the rubrospinal tract and other major descending tracts does not, this result implies that DIN output that affects cortex is essential for generation of the CST activity that induces the spinal cord plasticity, which is, in turn, directly responsible for the smaller H-reflex. The result extends the role of the cerebellum in learning and memory to include participation in induction of plasticity elsewhere in the CNS, specifically in the spinal cord. The cerebellum might simply support processes in sensorimotor cortex or elsewhere that change the spinal cord, or the cerebellum itself might undergo plasticity similar to that occurring with vestibulo-ocular reflex (VOR) or eyeblink conditioning.10aReflex10aVestibulo-Ocular1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1593050301999nas a2200253   4500008004100000022001400041245005300055210005100108260001200159300001200171490000800183520136000191653001701551653001301568653001101581653001501592653000801607653001101615653001601626100002101642700001301663700002101676856004801697       2001                        eng d  a0304-394000aTime course of H-reflex conditioning in the rat.0 aTime course of Hreflex conditioning in the rat  c04/2001  a85–880 v3023 aThis study sought to define the course of operantly conditioned change in the rat soleus H-reflex and to determine whether, like H-reflex conditioning and spinal stretch reflex conditioning in the monkey, it develops in distinct phases. Data from 33 rats in which the right soleus H-reflex was trained up (i.e. HRup mode) and 38 in which it was trained down (i.e. HRdown mode) were averaged to define the courses of H-reflex increase and decrease. In HRup rats, the H-reflex showed a large phase I increase within the first 2 days followed by gradual phase II increase that continued for weeks. In HRdown rats, the H-reflex appeared to show a small phase I decrease and then showed a gradual phase II decrease over weeks. In combination with other recent work, the data suggest that H-reflex conditioning begins with a rapid mode-appropriate alteration in corticospinal tract influence over the spinal arc of the H-reflex, which causes phase I change, and that the continuation of this altered influence induces gradual spinal cord plasticity that is responsible for phase II change. The results further establish the similarity of H-reflex conditioning in primates and rats. Thus, they encourage efforts to produce a single coherent model of the phenomenon based on data from the two species and indicate the potential clinical relevance of the rat data.10aconditioning10aLearning10aMemory10aplasticity10arat10aReflex10aSpinal Cord1 aChen, Xiang Yang1 aChen, Lu1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/11290393