@article {3163,
	title = {Operant conditioning of rat H-reflex affects motoneuron axonal conduction velocity.},
	journal = {Experimental brain research. Experimentelle Hirnforschung. Exp{\'e}rimentation c{\'e}r{\'e}brale},
	volume = {136},
	year = {2001},
	month = {01/2001},
	pages = {269{\textendash}273},
	abstract = {This study assessed the effects of operant conditioning of the H-reflex on motoneuron axonal conduction velocity in the rat. After measurement of the control H-reflex size, rats were either exposed for at least 40 days to the HRup or HRdown conditioning mode, in which reward occurred only if the soleus H-reflex was greater than (HRup mode) or less than (HRdown mode) a criterion or continued under the control condition (HRcon mode) in which the H-reflex was simply measured. We then measured axonal conduction velocity of triceps surae motor units of HRup, HRdown, and HRcon rats by stimulating the axon in the ventral root and recording from the tibial nerve. Conduction velocity was 8\% less in successful HRdown rats than in HRcon rats (P=0.02). Conduction velocity in HRup rats and unsuccessful HRdown rats was not significantly different from that in HRcon rats. Since recording bypassed the intra-spinal portion of the motoneuron, the change was clearly in the axon. This decrease was similar to the 6\% decrease previously found in successful HRdown monkeys. Unsuccessful HRdown rats and monkeys did not show this decrease. This result suggests that the mechanism of HRdown conditioning is similar in rats and monkeys and provides further support for the hypothesis that HRdown conditioning decreases motoneuron excitability by producing a positive shift in firing threshold. While traditional theories of learning emphasize synaptic plasticity, neuronal plasticity may also contribute to operantly conditioned behavioral changes.},
	keywords = {conduction velocity, H-Reflex, motoneuron, plasticity, Spinal Cord},
	issn = {0014-4819},
	doi = {10.1007/s002210000608},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/11206290},
	author = {Jonathan S. Carp and Xiang Yang Chen and Sheikh, H. and Jonathan Wolpaw}
}
@article {3174,
	title = {Constancy of motor axon conduction time during growth in rats.},
	journal = {Experimental brain research. Experimentelle Hirnforschung. Exp{\'e}rimentation c{\'e}r{\'e}brale},
	volume = {90},
	year = {1992},
	month = {08/1992},
	pages = {343{\textendash}345},
	abstract = {Axon conduction distance, conduction velocity, and conduction time were measured for individual triceps surae motoneurons in Sprague-Dawley rats weighing 230-630 g (i.e., age range 6-16 weeks). Both conduction distance (nerve length) and velocity were closely correlated with weight (r = 0.95 and r = 0.82, respectively). In contrast, conduction time did not change as weight increased nearly threefold. This striking constancy is probably due to a corresponding increase in axon diameter. It could contribute to maintenance of stable motor performance during rapid growth.},
	keywords = {development, motoneuron, motor axon, nerve conduction, rat},
	issn = {0014-4819},
	doi = {10.1007/BF00227247},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/1397148},
	author = {Xiang Yang Chen and Jonathan S. Carp and Jonathan Wolpaw}
}
