@article {3188,
	title = {Effects of H-reflex up-conditioning on GABAergic terminals on rat soleus motoneurons.},
	journal = {The European journal of neuroscience},
	volume = {28},
	year = {2008},
	month = {08/2008},
	pages = {668{\textendash}674},
	abstract = {To explore the role of spinal cord plasticity in motor learning, we evaluated the effects of H-reflex operant conditioning on GABAergic input to rat spinal motoneurons. Previous work indicated that down-conditioning of soleus H-reflex increases GABAergic input to soleus motoneurons. This study explored the effect of H-reflex up-conditioning on GABAergic input. Of nine rats exposed to H-reflex up-conditioning, up-conditioning was successful (H-reflex increase >or= 20\%) in seven and failed (change < 20\%) in two. These rats and eight naive control (i.e. unconditioned) rats were injected with cholera toxin subunit B-conjugated Alexa fluor 488 into the soleus muscle to retrogradely label soleus motoneurons. Sections containing soleus motoneurons were processed for GAD(67) [one of the two principal forms of the GABA-synthesizing enzyme glutamic acid decarboxylase (GAD)] with an ABC-peroxidase system. Two blinded independent raters counted and measured GABAergic terminals on these motoneurons. Unlike successful down-conditioning, which greatly increased the number of identifiable GABAergic terminals on the motoneurons, up-conditioning did not significantly change GABAergic terminal number. Successful up-conditioning did produce slight but statistically significant increases in GABAergic terminal diameter and soma coverage. These results are consistent with other data indicating that up- and down-conditioning are not mirror images of each other, but rather have different mechanisms. Although the marked changes in GABAergic terminals with down-conditioning probably contribute to H-reflex decrease, the modest changes in GABAergic terminals associated with up-conditioning may be compensatory or reactive plasticity, rather than the plasticity responsible for H-reflex increase. As a variety of spinal and supraspinal GABAergic neurons innervate motoneurons, the changes found with up-conditioning may be in terminals other than those affected in successful down-conditioning.},
	keywords = {activity-dependent plasticity, Learning, Memory, Motor control, Spinal Cord},
	issn = {1460-9568},
	doi = {10.1111/j.1460-9568.2008.06370.x},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/18657184},
	author = {Pillai, Shreejith and Wang, Yu and Jonathan Wolpaw and Xiang Yang Chen}
}
