@article {3197,
	title = {Corticospinal tract transection reduces H-reflex circadian rhythm in rats.},
	journal = {Brain research},
	volume = {942},
	year = {2002},
	month = {06/2002},
	pages = {101{\textendash}108},
	abstract = {In freely moving rats and monkeys, H-reflex amplitude displays a marked circadian variation without change in background motoneuron tone. In rats, the H-reflex is largest around noon and smallest around midnight. The present study evaluated in rats the effects on this rhythm of calibrated contusions of mid-thoracic spinal cord and mid-thoracic transection of specific spinal cord pathways. In 33 control rats, rhythm amplitude averaged 29.0(+/-2.6 S.E.)\% of H-reflex amplitude. Contusion injuries at T8-9 that destroyed 53-88\% of the white matter significantly reduced the rhythm to 18.9(+/-2.4)\% of H-reflex amplitude. Transection of the ipsilateral lateral column, which contains the rubrospinal, vestibulospinal, and reticulospinal tracts, or bilateral transection of the dorsal column ascending tract did not affect rhythm amplitude or phase. In contrast, bilateral transection of the main corticospinal tract significantly reduced the rhythm to 14.7(+/-6.6)\%. These results indicate that the H-reflex circadian rhythm depends in part on descending influence from the brain and that this influence is conveyed by the main corticospinal tract.},
	keywords = {circadian rhythms, corticospinal tract, diurnal rhythm, H-Reflex, rat, spinal cord injury},
	issn = {0006-8993},
	doi = {10.1016/S0006-8993(02)02702-6},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/12031858},
	author = {Xiang Yang Chen and Lu Chen and Jonathan Wolpaw and Jakeman, Lyn B.}
}
@article {3288,
	title = {Adaptive plasticity and diurnal rhythm in the primate spinal stretch reflex are independent phenomena.},
	journal = {Brain research},
	volume = {300},
	year = {1984},
	month = {05/1984},
	pages = {385{\textendash}391},
	abstract = {Recent studies have revealed two phenomena producing considerable variation in amplitude of the initial, purely segmental, largely monosynaptic, response to sudden muscle stretch, the spinal stretch reflex (SSR), without change in background EMG activity or initial muscle length. The first is small and short-term, a modest diurnal rhythm in SSR amplitude. The second is large and long-term, marked adaptive change in SSR amplitude which occurs gradually over weeks and months when animals are rewarded for such change. This second phenomenon may involve persistent segmental alteration, and, if so, could constitute a technically accessible substrate of memory. The present study compared the two phenomena and sought evidence of interaction between them. The diurnal rhythm persisted, without change in phase and with only minimal change in amplitude, despite the occurrence of marked adaptive change. Animals did not utilize the rhythm to increase reward percentage by altering daily performance schedules. These results suggest that the mechanisms of the diurnal rhythm and of adaptive plasticity in SSR amplitude are separate and independent. The diurnal rhythm{\textquoteright}s effect on movement was not altered by adaptive change in SSR amplitude. This effect was comparable to adaptive change{\textquoteright}s effect on movement when both were expressed as change in movement/change in SSR amplitude.},
	keywords = {adaptive plasticity, diurnal rhythm, Learning, Memory, primate, stretch reflex},
	issn = {0006-8993},
	doi = {10.1016/0006-8993(84)90852-7},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/6539634},
	author = {Jonathan Wolpaw and Noonan, P. A. and O{\textquoteright}Keefe, J. A.}
}
@article {3329,
	title = {Diurnal rhythm in the spinal stretch reflex.},
	journal = {Brain research},
	volume = {244},
	year = {1982},
	month = {07/1982},
	pages = {365{\textendash}369},
	abstract = {We studied primate spinal stretch reflex (SSR) amplitude as a function of time of day. SSR amplitude was greatest around midnight and smallest around noon. The diurnal rhythm was not simply a function of number of trials, or of the lighting cycle. This rhythm offers an opportunity to study the neuronal and synaptic mechanisms producing a diurnal change in CNS function. Its existence indicates that the CNS response to a given limb disturbance, and thus the CNS activity underlying a given performance, varies with time of day.},
	keywords = {circadian rhythm, diurnal rhythm, muscle stretch, primate, spinal reflex, stretch reflex},
	issn = {0006-8993},
	doi = {10.1016/0006-8993(82)90099-3},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/6889452},
	author = {Jonathan Wolpaw and Seegal, R. F.}
}
