@article {3158,
	title = {Corticospinal transmission to motoneurons in cervical spinal cord slices from adult rats.},
	journal = {Life sciences},
	volume = {72},
	year = {2002},
	month = {12/2002},
	pages = {389{\textendash}396},
	abstract = {Cervical spinal cord slices were prepared from adult rats. Intracellular recordings from motoneurons revealed that electrical stimulation of the ventralmost part of the dorsal funiculus (which contains primarily descending corticospinal axons) elicited EPSPs in 75\% of the neurons. The latencies of these EPSPs tended to be shorter than those elicited by dorsal horn gray matter stimulation. Pairs of subthreshold dorsal funiculus stimuli were able to elicit action potentials in motoneurons. These data are consistent with previous morphological and electrophysiological studies indicating that cervical motoneurons receive both mono-and polysynaptic corticospinal inputs. In addition, motoneurons were markedly depolarized by iontophoretic application of AMPA or KA (7 out of 7 neurons), but only weakly depolarized by NMDA (1 out of 6 neurons). CNQX (but not AP-5) blocked EPSPs elicited by dorsal funiculus stimulation. Thus, corticospinal transmission to motoneurons is mediated primarily by non-NMDA glutamate receptors.},
	keywords = {adult rat, cervical spinal cord, motoneuron, slice},
	issn = {0024-3205},
	doi = {10.1016/S0024-3205(02)02279-8},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/12467879},
	author = {Hori, N. and Jonathan S. Carp and Carpenter, D. O. and Akaike, N.}
}
@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 {3171,
	title = {The volitional nature of the simplest reflex.},
	journal = {Acta neurobiologiae experimentalis},
	volume = {53},
	year = {1993},
	pages = {103{\textendash}111},
	abstract = {Recent studies suggest that none of the behaviors of the vertebrate CNS are fixed responses incapable of change. Even the simplest reflex of all, the two-neuron, monosynaptic spinal stretch reflex (SSR), undergoes adaptive change under appropriate circumstances. Operantly conditioned SSR change occurs gradually over days and weeks and is associated with a complex pattern of CNS plasticity at both spinal and supraspinal sites.},
	keywords = {behavior, Brain, conditioning, human physiology, Learning, Memory, motoneuron, nature, primate, Reflex, Spinal Cord, spinal site, supra spinal site, vertebrate},
	issn = {0065-1400},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/8317238},
	author = {Jonathan Wolpaw and Jonathan S. Carp}
}
@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}
}
@article {3175,
	title = {Alterations in motoneuron properties induced by acute dorsal spinal hemisection in the decerebrate cat.},
	journal = {Experimental brain research. Experimentelle Hirnforschung. Exp{\'e}rimentation c{\'e}r{\'e}brale},
	volume = {83},
	year = {1991},
	month = {02/1991},
	pages = {539{\textendash}548},
	abstract = {Using intracellular recording techniques, we studied the response characteristics of two separate populations of triceps surae motoneurons in unanesthetized decerebrate cats, recorded before and after low thoracic hemisection of the spinal cord. In each preparation, we studied the response properties of one group of motoneurons and the protocol was then repeated for a separate group, immediately following the dorsal hemisection. In each group, we examined both the minimum firing rates of motoneurons during intracellular current injection and a range of cellular properties, including input resistance, rheobase current and afterhyperpolarization time course and magnitude. Although earlier studies from this laboratory have shown substantial reductions in minimum firing rate in reflexively active motoneurons in the hemisected decerebrated preparation, the response of motoneurons to intracellular current injection in the current preparation proved to be quite different. Minimum firing rates were either normal or even somewhat higher in the post-lesion group, while the time course of the afterhyperpolarization was shortened. Moreover, these effects were not evenly distributed across the motoneuron pool. The rate effect was most evident in motoneurons with higher conduction velocity, while the afterhyperpolarization effect occurred predominantly in motoneurons with lower conduction velocity. Neither of these effects could be accounted for by lesion-induced changes in other cellular properties. We conclude that tonically active neurons with descending axons traversing dorsolateral white matter may influence both the discharge characteristics and membrane properties of spinal motoneurons in novel ways, presumably by modifying voltage or calcium activated motoneuronal conductances. The previously described reactions in the firing rate of motoneurons after such lesions appear to be mediated by different means, perhaps by alterations in synaptic input from segmental interneurons.},
	keywords = {afterhyperpolarization, cat, lesion, motoneuron, repetitive discharge, Spinal Cord},
	issn = {0014-4819},
	doi = {10.1007/BF00229832},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/2026196},
	author = {Jonathan S. Carp and Powers, R. K. and Rymer, W. Z.}
}
@article {3178,
	title = {Memory traces in spinal cord produced by H-reflex conditioning: effects of post-tetanic potentiation.},
	journal = {Neuroscience letters},
	volume = {103},
	year = {1989},
	month = {08/1989},
	pages = {113{\textendash}119},
	abstract = {Operant conditioning of the wholly spinal, largely monosynaptic triceps surae H-reflex in monkeys causes changes in lumbosacral spinal cord that persist after removal of supraspinal influence. We evaluated the interaction between post-tetanic potentiation and these memory traces. Animals in which the triceps surae H-reflex in one leg had been increased or decreased by conditioning were deeply anesthetized, and monosynaptic reflexes to L6-S1 dorsal root stimulation were recorded before and after tetanization from both legs for 3 days after thoracic cord transection. Animals remained anesthetized throughout and were sacrificed by overdose. Reflex asymmetries consistent with the effect of H-reflex conditioning were present after transection and persisted through the 3 days of study. Tetanization affected conditioned leg and control leg reflexes similarly. This finding suggests that, while post-tetanic potentiation and probably H-reflex conditioning alter Ia synaptic transmission, the two phenomena have different mechanisms.},
	keywords = {conditioning, Learning, Memory, motoneuron, potentiation, primate, spinal reflex},
	issn = {0304-3940},
	doi = {10.1016/0304-3940(89)90495-3},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/2779852},
	author = {Jonathan Wolpaw and Jonathan S. Carp and Lee, C. L.}
}
