@article {3192,
	title = {The cerebellum in maintenance of a motor skill: a hierarchy of brain and spinal cord plasticity underlies H-reflex conditioning.},
	journal = {Learning \& memory (Cold Spring Harbor, N.Y.)},
	volume = {13},
	year = {2006},
	month = {03/2006},
	pages = {208{\textendash}215},
	abstract = {Operant conditioning of the H-reflex, the electrical analog of the spinal stretch reflex, is a simple model of skill acquisition and involves plasticity in the spinal cord. Previous work showed that the cerebellum is essential for down-conditioning the H-reflex. This study asks whether the cerebellum is also essential for maintaining down-conditioning. After rats decreased the soleus H-reflex over 50 d in response to the down-conditioning protocol, the cerebellar output nuclei dentate and interpositus (DIN) were ablated, and down-conditioning continued for 50-100 more days. In naive (i.e., unconditioned) rats, DIN ablation itself has no significant long-term effect on H-reflex size. During down-conditioning prior to DIN ablation, eight Sprague-Dawley rats decreased the H-reflex to 57\% (+/-4 SEM) of control. It rose after ablation, stabilizing within 2 d at about 75\% and remaining there until approximately 40 d after ablation. It then rose to approximately 130\%, where it remained through the end of study 100 d after ablation. Thus, DIN ablation in down-conditioned rats caused an immediate increase and a delayed increase in the H-reflex. The final result was an H-reflex significantly larger than that prior to down-conditioning. Combined with previous work, these remarkable results suggest that the spinal cord plasticity directly responsible for down-conditioning, which survives only 5-10 d on its own, is maintained by supraspinal plasticity that survives approximately 40 d after loss of cerebellar output. Thus, H-reflex conditioning seems to depend on a hierarchy of brain and spinal cord plasticity to which the cerebellum makes an essential contribution.},
	keywords = {Spinal Cord},
	issn = {1072-0502},
	doi = {10.1101/lm.92706},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/16585796},
	author = {Jonathan Wolpaw and Xiang Yang Chen}
}
