02708nas a2200373 4500008004100000022001400041245010900055210006900164260001200233300001100245490000600256520162400262653002201886653001201908653001001920653001801930653002501948653001501973653002901988653000902017653002402026653001702050653001202067653000902079653002502088653004102113653002602154100001602180700002302196700001902219700002802238700002002266856004802286 2006 eng d a1557-170X00aAnalysis of the correlation between local field potentials and neuronal firing rate in the motor cortex.0 aAnalysis of the correlation between local field potentials and n c09/2006 a6185-80 v13 a

Neuronal firing rate has been the signal of choice for invasive motor brain machine interfaces (BMI). The use of local field potentials (LFP) in BMI experiments may provide additional dendritic information about movement intent and may improve performance. Here we study the time-varying amplitude modulated relationship between local field potentials (LFP) and single unit activity (SUA) in the motor cortex. We record LFP and SUA in the primary motor cortex of rats trained to perform a lever pressing task, and evaluate the correlation between pairs of peri-event time histograms (PETH) and movement evoked local field potentials (mEP) at the same electrode. Three different correlation coefficients were calculated and compared between the neuronal PETH and the magnitude and power of the mEP. Correlation as high as 0.7 for some neurons occurred between the PETH and the mEP magnitude. As expected, the correlations between the single trial LFP and SUV are much lower due to the inherent variability of both signals.

10aAction Potentials10aAnimals10aBrain10aBrain Mapping10aElectric Stimulation10aElectrodes10aEvoked Potentials, Motor10aMale10aModels, Statistical10aMotor Cortex10aNeurons10aRats10aRats, Sprague-Dawley10aSignal Processing, Computer-Assisted10aSynaptic Transmission1 aWang, Yiwen1 aSanchez, Justin, C1 aPrincipe, Jose1 aMitzelfelt, Jeremiah, D1 aGunduz, Aysegul uhttp://www.ncbi.nlm.nih.gov/pubmed/1794674503057nas a2200169 4500008004100000022001400041245008900055210006900144260001200213300001400225490000700239520252400246653002602770100002302796700002102819856004702840 1994 eng d a0022-307700aMotoneuron plasticity underlying operantly conditioned decrease in primate H-reflex.0 aMotoneuron plasticity underlying operantly conditioned decrease  c07/1994 a431–4420 v723 a1. Monkeys can gradually increase or decrease the size of the triceps surae H-reflex in response to an operant conditioning task. This conditioning modifies the spinal cord. To determine the location and nature of the spinal cord plasticity and define its role in the behavioral change (i.e., H-reflex increase or decrease) we have recorded intracellularly from triceps surae motoneurons in conditioned animals and compared the results with data from naive (i.e., unconditioned) animals. 2. Eleven monkeys (Macaca nemestrina, male) were exposed to the HRdown conditioning mode, in which reward occurred when H-reflex size in one leg (i.e., the trained leg) was below a criterion value. In six animals (5.1-8.2 kg) H-reflex size in the trained leg fell to 24-58% of its initial value, whereas in the other five animals (4.0-5.5 kg) it remained at 92-114% of its initial value. This outcome, which was in accord with recent data indicating that success in HRdown conditioning is age dependent, allowed comparison of intracellular data from successful HRdown animals with data from unsuccessful animals as well as with data from naive (i.e., unconditioned) animals. 3. Intracellular recordings were obtained from 221 triceps surae motoneurons on trained and control sides of successful and unsuccessful HRdown animals. Measurements included axonal conduction velocity, input resistance, time constant, electrotonic length, rheobase, firing threshold, afterhyperpolarization duration and amplitude, and composite homonymous and heteronymous excitatory postsynaptic potentials to peripheral nerve stimulation. Results were compared with data from 109 triceps surae motoneurons in naive animals. 4. Motoneurons from the trained side of successful HRdown animals had a significantly more positive average firing threshold (-52 vs. -55 mV) and a significantly lower average conduction velocity (67 vs. 71 m/s) than those from naive animals. In contrast, motoneurons from the trained side of unsuccessful HRdown animals were not significantly different from naive motoneurons. 5. These data are consistent with the hypothesis that operantly conditioned decrease in H-reflex size is due to a positive shift in motoneuron firing threshold and a consequent increase in the depolarization needed to reach that threshold. 6. The more positive firing threshold, if present in the axon as well as in the soma, could also account for the decreased conduction velocity observed in motoneurons from the trained side of successful animals.10aSynaptic Transmission1 aCarp, Jonathan, S.1 aWolpaw, Jonathan uhttp://www.ncbi.nlm.nih.gov/pubmed/796502501958nas a2200169 4500008004100000022001400041245009600055210006900151260001200220300001400232490000800246520141700254653002601671100002301697700002101720856004701741 1981 eng d a0022-356500aModification of spinal cord transmission by an interaction of chlorpromazine and phenytoin.0 aModification of spinal cord transmission by an interaction of ch c02/1981 a270–2740 v2163 aCat spinal cord monosynaptic activity during slow repetitive stimulation (0.2 Hz) and post-tetanic potentiation was used to evaluate the combination effects of phenytoin and chlorpromazine. The drug effects were compared in anesthetized cats with either high spinal transection or intact central nervous systems to determine whether the drugs were acting segmentally or suprasegmentally. When chlorpromazine and phenytoin were given in combination to intact animals, the depressant effect on the monosynaptic response was limited to 50% of control, which was not more than the maximum effect of either drug given alone. In spinal animals, chlorpromazine reversed the phenytoin-induced depression during 0.2 Hz stimulation, whereas only the effects of phenytoin on post-tetanic potentiation were evident after the drug combination. These results show that although phenytoin and chlorpromazine each have a depressant effect on spinal cord transmission, the combined effect is limited to a 50% decrease in intact animals. It is suggested that this occlusive drug effect demonstrates that the drug combination has a limited depressant action in the intact nervous system, an action which permits the expression of the effects of these drugs on the other elements of the reflex arc. Collectively, these actions of the drug combination are consistent with their known efficacy in treating certain cases of spasticity.10aSynaptic Transmission1 aCarp, Jonathan, S.1 aAnderson, R., J. uhttp://www.ncbi.nlm.nih.gov/pubmed/6257885