<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jonathan Wolpaw</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The complex structure of a simple memory.</style></title><secondary-title><style face="normal" font="default" size="100%">Trends in neurosciences</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">H-Reflex</style></keyword><keyword><style  face="normal" font="default" size="100%">Learning</style></keyword><keyword><style  face="normal" font="default" size="100%">Memory</style></keyword><keyword><style  face="normal" font="default" size="100%">operant conditioning</style></keyword><keyword><style  face="normal" font="default" size="100%">plasticity</style></keyword><keyword><style  face="normal" font="default" size="100%">Spinal Cord</style></keyword><keyword><style  face="normal" font="default" size="100%">stretch reflex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1997</style></year><pub-dates><date><style  face="normal" font="default" size="100%">12/1997</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/9416673</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">20</style></volume><pages><style face="normal" font="default" size="100%">588–594</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Operant conditioning of the vertebrate H-reflex, which appears to be closely related to learning that occurs in real life, is accompanied by plasticity at multiple sites. Change occurs in the firing threshold and conduction velocity of the motoneuron, in several different synaptic terminal populations on the motoneuron, and probably in interneurons as well. Change also occurs contralaterally. The corticospinal tract probably has an essential role in producing this plasticity. While certain of these changes, such as that in the firing threshold, are likely to contribute to the rewarded behavior (primary plasticity), others might preserve previously learned behaviors (compensatory plasticity), or are simply activity-driven products of change elsewhere (reactive plasticity). As these data and those from other simple vertebrate and invertebrate models indicate, a complex pattern of plasticity appears to be the necessary and inevitable outcome of even the simplest learning.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jonathan Wolpaw</style></author><author><style face="normal" font="default" size="100%">Herchenroder, P. A.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Operant conditioning of H-reflex in freely moving monkeys.</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of neuroscience methods</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">conditioning</style></keyword><keyword><style  face="normal" font="default" size="100%">H-Reflex</style></keyword><keyword><style  face="normal" font="default" size="100%">Memory</style></keyword><keyword><style  face="normal" font="default" size="100%">plasticity</style></keyword><keyword><style  face="normal" font="default" size="100%">primate</style></keyword><keyword><style  face="normal" font="default" size="100%">spinal reflex</style></keyword><keyword><style  face="normal" font="default" size="100%">stretch reflex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1990</style></year><pub-dates><date><style  face="normal" font="default" size="100%">02/1990</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/2319815</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">31</style></volume><pages><style face="normal" font="default" size="100%">145–152</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The H-reflex, the electrical analog of the stretch reflex or tendon jerk, is the simplest behavior of the primate CNS. It is subserved by a wholly spinal two-neuron reflex arc. Recent studies show that this reflex can be increased or decreased by operant conditioning, and that such conditioning causes plastic changes in the spinal cord itself. Thus, H-reflex conditioning provides a powerful new model for investigating primate memory traces. The key feature of this model, the conditioning task, originally required animal restraint. This report describes a new tether-based design that allows H-reflex measurement and conditioning without restraint. This design integrates the conditioning task into the life of the freely moving animal.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jonathan Wolpaw</style></author><author><style face="normal" font="default" size="100%">Dowman, R.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Spinal stretch reflex and cortical evoked potential amplitudes versus muscle stretch amplitude in the monkey arm.</style></title><secondary-title><style face="normal" font="default" size="100%">Electroencephalography and clinical neurophysiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">muscle stretch</style></keyword><keyword><style  face="normal" font="default" size="100%">primate</style></keyword><keyword><style  face="normal" font="default" size="100%">Somatosensory Cortex</style></keyword><keyword><style  face="normal" font="default" size="100%">somatosensory evoked potential</style></keyword><keyword><style  face="normal" font="default" size="100%">spinal reflex</style></keyword><keyword><style  face="normal" font="default" size="100%">stretch reflex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1988</style></year><pub-dates><date><style  face="normal" font="default" size="100%">04/1988</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/2450738</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">69</style></volume><pages><style face="normal" font="default" size="100%">394–397</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">While investigating operant conditioning of the primate spinal stretch reflex (SSR), we studied SSR amplitude and cortical somatosensory evoked potential (SEP) amplitude as stretch amplitude changed in the monkey arm. Initial muscle length and background EMG activity remained constant. With change in stretch amplitude (and proportional change in stretch velocity and acceleration), changes in SSR and SEP amplitudes were respectively 0.75 and 0.66 as great. The lesser change in SSR amplitude may reflect saturation of Ia afferents, while that in SEP amplitude may also reflect participation of other peripheral receptors.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jonathan S. Carp</style></author><author><style face="normal" font="default" size="100%">Rymer, W. Z.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Enhancement by serotonin of tonic vibration and stretch reflexes in the decerebrate cat.</style></title><secondary-title><style face="normal" font="default" size="100%">Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">bistable neuronal behavior</style></keyword><keyword><style  face="normal" font="default" size="100%">serotonin</style></keyword><keyword><style  face="normal" font="default" size="100%">Spinal Cord</style></keyword><keyword><style  face="normal" font="default" size="100%">stretch reflex</style></keyword><keyword><style  face="normal" font="default" size="100%">tonic vibration reflex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1986</style></year><pub-dates><date><style  face="normal" font="default" size="100%">03/1986</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/3007191</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">62</style></volume><pages><style face="normal" font="default" size="100%">111–122</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The effects of pharmacological manipulation of serotonergic systems on spinal reflexes were determined in the unanesthetized decerebrate cat. The prolonged motor output that continues after cessation of high frequency longitudinal tendon vibration was strongly enhanced by the serotonin reuptake blocker fluoxetine and the serotonin precursor 5-hydroxytryptophan, and was decreased by the serotonin receptor antagonist methysergide. In addition, both dynamic and static stretch reflex stiffness was markedly increased by fluoxetine and 5-hydroxytryptophan, while methysergide produced a decrease in stretch reflex stiffness. These powerful effects on tonic vibration and stretch reflexes could not be explained by drug-induced alterations in muscle spindle primary afferent discharge. In light of other recent results on serotonin-mediated effects on motoneurons, we believe that the effects of these agents result from modification of an intrinsically mediated prolonged depolarization of spinal neurons. However, the possibility that these drugs modify longlasting discharge in associated interneuronal pathways cannot be ruled out.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jonathan Wolpaw</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Adaptive plasticity in the spinal stretch reflex: an accessible substrate of memory?.</style></title><secondary-title><style face="normal" font="default" size="100%">Cellular and molecular neurobiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Learning</style></keyword><keyword><style  face="normal" font="default" size="100%">Memory</style></keyword><keyword><style  face="normal" font="default" size="100%">plasticity</style></keyword><keyword><style  face="normal" font="default" size="100%">primate</style></keyword><keyword><style  face="normal" font="default" size="100%">spinal reflex</style></keyword><keyword><style  face="normal" font="default" size="100%">stretch reflex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1985</style></year><pub-dates><date><style  face="normal" font="default" size="100%">06/1985</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/3161616</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">5</style></volume><pages><style face="normal" font="default" size="100%">147–165</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The study of the substrates of memory in higher vertebrates is one of the major problems of neurobiology. A simple and technically accessible experimental model is needed. Recent studies have demonstrated long-term adaptive plasticity, a form of memory, in the spinal stretch reflex (SSR). The SSR is due largely to a two-neuron monosynaptic arc, the simplest, best-defined, and most accessible pathway in the primate central nervous system (CNS). Monkeys can slowly change SSR amplitude without a change in initial muscle length or alpha motoneuron tone, when reward is made contingent on amplitude. Change occurs over weeks and months and persists for long periods. It is relatively specific to the agonist muscle and affects movement. The salient features of SSR adaptive plasticity, combined with clinical and laboratory evidence indicating spinal cord capacity for intrinsic change, suggest that SSR change eventually involves persistent segmental alteration. If this is the case, SSR plasticity should be a powerful model for studying the neuronal and synaptic substrates of memory in a primate.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jonathan Wolpaw</style></author><author><style face="normal" font="default" size="100%">O'Keefe, J. A.</style></author><author><style face="normal" font="default" size="100%">Kieffer, V. A.</style></author><author><style face="normal" font="default" size="100%">Sanders, M. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Reduced day-to-day variation accompanies adaptive plasticity in the primate spinal stretch reflex.</style></title><secondary-title><style face="normal" font="default" size="100%">Neuroscience letters</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Learning</style></keyword><keyword><style  face="normal" font="default" size="100%">Memory</style></keyword><keyword><style  face="normal" font="default" size="100%">plasticity</style></keyword><keyword><style  face="normal" font="default" size="100%">primate</style></keyword><keyword><style  face="normal" font="default" size="100%">spinal reflex</style></keyword><keyword><style  face="normal" font="default" size="100%">stretch reflex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1985</style></year><pub-dates><date><style  face="normal" font="default" size="100%">03/1985</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/3991057</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">54</style></volume><pages><style face="normal" font="default" size="100%">165–171</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Monkeys can change the amplitude of the spinal stretch reflex (SSR), or M1, when reward is made contingent on amplitude. The present study demonstrates that reduced SSR day-to-day variation accompanies such adaptive SSR change. This finding supports the assumption that initial, phase I, SSR change results from contingency-appropriate stabilization of tonic activity in relevant descending spinal cord pathways.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jonathan Wolpaw</style></author><author><style face="normal" font="default" size="100%">Noonan, P. A.</style></author><author><style face="normal" font="default" size="100%">O'Keefe, J. A.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Adaptive plasticity and diurnal rhythm in the primate spinal stretch reflex are independent phenomena.</style></title><secondary-title><style face="normal" font="default" size="100%">Brain research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">adaptive plasticity</style></keyword><keyword><style  face="normal" font="default" size="100%">diurnal rhythm</style></keyword><keyword><style  face="normal" font="default" size="100%">Learning</style></keyword><keyword><style  face="normal" font="default" size="100%">Memory</style></keyword><keyword><style  face="normal" font="default" size="100%">primate</style></keyword><keyword><style  face="normal" font="default" size="100%">stretch reflex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1984</style></year><pub-dates><date><style  face="normal" font="default" size="100%">05/1984</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/6539634</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">300</style></volume><pages><style face="normal" font="default" size="100%">385–391</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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's effect on movement was not altered by adaptive change in SSR amplitude. This effect was comparable to adaptive change's effect on movement when both were expressed as change in movement/change in SSR amplitude.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jonathan Wolpaw</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Adaptive plasticity in the primate spinal stretch reflex: reversal and re-development.</style></title><secondary-title><style face="normal" font="default" size="100%">Brain research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Learning</style></keyword><keyword><style  face="normal" font="default" size="100%">Memory</style></keyword><keyword><style  face="normal" font="default" size="100%">plasticity</style></keyword><keyword><style  face="normal" font="default" size="100%">primate</style></keyword><keyword><style  face="normal" font="default" size="100%">spinal reflex</style></keyword><keyword><style  face="normal" font="default" size="100%">stretch reflex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1983</style></year><pub-dates><date><style  face="normal" font="default" size="100%">11/1983</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/6640320</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">278</style></volume><pages><style face="normal" font="default" size="100%">299–304</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Monkeys can gradually increase or decrease the amplitude of the segmentally mediated spinal stretch reflex (SSR) without change in initial muscle length or background EMG activity. Both increase (under the SSR increases mode) and decrease (under the SSR decreases mode) occur slowly, progressing steadily over weeks. The present study investigated reversal and re-development of SSR amplitude change. Over a period of months, following collection of control data, monkeys were exposed to one mode, then to the other, and then to the first mode again. Development, reversal, and re-development of change all took place over weeks, following very similar courses. These data are consistent with the hypothesis that persistent segmental alteration underlies SSR amplitude change. Such persistent segmental alteration would constitute a technically accessible substrate of memory.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jonathan Wolpaw</style></author><author><style face="normal" font="default" size="100%">Kieffer, V. A.</style></author><author><style face="normal" font="default" size="100%">Seegal, R. F.</style></author><author><style face="normal" font="default" size="100%">Braitman, D. J.</style></author><author><style face="normal" font="default" size="100%">Sanders, M. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Adaptive plasticity in the spinal stretch reflex.</style></title><secondary-title><style face="normal" font="default" size="100%">Brain research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Learning</style></keyword><keyword><style  face="normal" font="default" size="100%">Memory</style></keyword><keyword><style  face="normal" font="default" size="100%">plasticity</style></keyword><keyword><style  face="normal" font="default" size="100%">primate</style></keyword><keyword><style  face="normal" font="default" size="100%">spinal reflex</style></keyword><keyword><style  face="normal" font="default" size="100%">stretch reflex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1983</style></year><pub-dates><date><style  face="normal" font="default" size="100%">05/1983</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/6860948</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">267</style></volume><pages><style face="normal" font="default" size="100%">196–200</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Monkeys can change the amplitude of the spinal stretch reflex without change in initial alpha motor neuron tone, as measured by EMG, or in initial muscle length. Change is apparent in 5-10 days, continues to develop over weeks, and persists during inactive periods. Spinal stretch reflex change may be a valuable system for studying the neuronal and synaptic bases of an adaptive change in primate CNS function.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jonathan Wolpaw</style></author><author><style face="normal" font="default" size="100%">Seegal, R. F.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Diurnal rhythm in the spinal stretch reflex.</style></title><secondary-title><style face="normal" font="default" size="100%">Brain research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">circadian rhythm</style></keyword><keyword><style  face="normal" font="default" size="100%">diurnal rhythm</style></keyword><keyword><style  face="normal" font="default" size="100%">muscle stretch</style></keyword><keyword><style  face="normal" font="default" size="100%">primate</style></keyword><keyword><style  face="normal" font="default" size="100%">spinal reflex</style></keyword><keyword><style  face="normal" font="default" size="100%">stretch reflex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1982</style></year><pub-dates><date><style  face="normal" font="default" size="100%">07/1982</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/6889452</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">244</style></volume><pages><style face="normal" font="default" size="100%">365–369</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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.</style></abstract></record></records></xml>