@article {3385,
	title = {Operant conditioning of the soleus H-reflex does not induce long-term changes in the gastrocnemius H-reflexes and does not disturb normal locomotion in humans.},
	journal = {J Neurophysiol},
	volume = {112},
	year = {2014},
	month = {09/2014},
	pages = {1439-46},
	abstract = {<p>In normal animals, operant conditioning of the spinal stretch reflex or the H-reflex has lesser effects on synergist muscle reflexes. In rats and people with incomplete spinal cord injury (SCI), soleus H-reflex operant conditioning can improve locomotion. We studied in normal humans the impact of soleus H-reflex down-conditioning on medial (MG) and lateral gastrocnemius (LG) H-reflexes and on locomotion. Subjects completed 6 baseline and 30 conditioning sessions. During conditioning trials, the subject was encouraged to decrease soleus H-reflex size with the aid of visual feedback. Every sixth session, MG and LG H-reflexes were measured. Locomotion was assessed before and after conditioning. In successfully conditioned subjects, the soleus H-reflex decreased 27.2\%. This was the sum of within-session (task dependent) adaptation (13.2\%) and across-session (long term) change (14\%). The MG H-reflex decreased 14.5\%, due mainly to task-dependent adaptation (13.4\%). The LG H-reflex showed no task-dependent adaptation or long-term change. No consistent changes were detected across subjects in locomotor H-reflexes, EMG activity, joint angles, or step symmetry. Thus, in normal humans, soleus H-reflex down-conditioning does not induce long-term changes in MG/LG H-reflexes and does not change locomotion. In these subjects, task-dependent adaptation of the soleus H-reflex is greater than it is in people with SCI, whereas long-term change is less. This difference from results in people with SCI is consistent with the fact that long-term change is beneficial in people with SCI, since it improves locomotion. In contrast, in normal subjects, long-term change is not beneficial and may necessitate compensatory plasticity to preserve satisfactory locomotion.</p>},
	keywords = {Learning, plasticity, Rehabilitation, Spinal Cord, synergists},
	issn = {1522-1598},
	doi = {10.1152/jn.00225.2014},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/24944216},
	author = {Makihara, Yukiko and Segal, Richard L and Jonathan Wolpaw and Thompson, Aiko K}
}
