Context Dependency in the Globus Pallidus Internal Segment During Targeted Arm Movements

Gdowski, Martha Johnson; Miller, Lee E.; Parrish, Todd B.; Nénonéné, Emmanuel K.; Houk, James C.

doi:10.1152/jn.2001.85.2.998

Cited by 42 publications

(35 citation statements)

References 29 publications

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“…In summary, the results of this study extend and quantify our prior descriptive analysis of the selective modulation GPi neurons in association with movements generated in specific behavioral contexts (Gdowski et al, 2001). In the present study, nearly 100% (80/82) of the task-modulated GPi neurons had 20-80% reductions of their depths of modulation during the return, unrewarded movements relative to during cued, rewarded movements.…”

Section: Summary and Interpretationssupporting

confidence: 82%

“…Neuron P229 (A) had significant increases in discharge in association with cued movements to all four targets, but not during the return movements. We have observed such differences in GPi discharge previously, which we described as "context dependent" to denote that the neuronal response was contingent upon the behavioral setting during which movements were executed (Gdowski et al, 2001). As indicated in Table 2, 42 neurons (53%) were modulated like neuron P229 shown in Figure 2A, displaying statistically significant increases in discharge in association with the cued movements.…”

Section: Neurons With Increasing and Decreasing Responsesmentioning

confidence: 93%

“…The mean gain values (mean of variable a in linear regression calculation for all 4 targets) were calculated for each neuron for both paired and kinematically-similar analyses. Refer to (Gdowski et al, 2001) for further explanation of standard versus kinematically similar analyses.…”

Section: Analysis Of Attenuation Of Dom In Return Vs Cued Movementsmentioning

confidence: 99%

“…Despite these accounts, our initial observation of context dependence was unexpected, since we had not originally designed our behavioral tasks to elucidate contextual differences (Gdowski et al, 2001). These early findings let us to expand upon those differences in the present study.…”

Section: Introductionmentioning

confidence: 99%

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Signaling patterns of globus pallidus internal segment neurons during forearm rotation

et al. 2007

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We recorded extracellular single unit discharges of globus pallidus internal segment (GPi) neurons in monkeys performing a visually-driven forearm rotation movement task in order to quantify how discharge patterns changed in relation to kinematic parameters. Subjects grasped a handle that rotated about its axis while facing a video screen displaying visual targets. Continuous visual feedback of handle rotation position was provided. Monkeys generated forearm rotation movements of ±35° and ±70° amplitude in order to align the cursor and targets. Trial records were aligned to forearm rotation onset in order to compare the discharge patterns that were associated with movements of different amplitudes, velocities, and directions. In addition, we quantified the depth of modulation of neuronal discharge associated with movements generated in two different task phases. Comparisons of discharge patterns were made between the visually-guided, rewarded phase ("cued movements") and the self-paced, unrewarded phase that returned the monkey to the task start position ("return movements") by quantifying the goodness of fit between neuronal discharge during cued and return movements.Our analyses revealed no systematic relationship between the depth of modulation of GPi neurons and forearm rotation amplitude, direction, or velocity. Further, comparisons between the two behavioral contexts revealed a systematic attenuation of modulation that could not be attributed to differences in movement velocity. Collectively, these findings suggest that the GPi neurons that we studied were not significantly involved in mediating movement kinematics, but may have instead been instrumental in the processing of information about the behavioral context during which movements were generated.

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Section: Summary and Interpretationssupporting

confidence: 82%

Section: Neurons With Increasing and Decreasing Responsesmentioning

confidence: 93%

Section: Analysis Of Attenuation Of Dom In Return Vs Cued Movementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Signaling patterns of globus pallidus internal segment neurons during forearm rotation

et al. 2007

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“…For example, reward prediction errors, often referred to as temporal difference error in reinforcement learning algorithms, are encoded by the midbrain dopamine neurons (Schultz, 1998). Similarly, activity of neurons coding the metrics of a single movement is often modulated by expected reward in various cortical and subcortical areas (Watanabe, 1996;Kawagoe et al, 1998;Leon and Shadlen, 1999;Gdowski et al, 2001;Kobayashi et al, 2002;Ikeda and Hikosaka, 2003;Roesch and Olson, 2003). Whereas most of these studies have examined how neural activity is influenced by expected rewards in a delayed response task, the activity of neurons in the prefrontal cortex (Barraclough et al, 2004) and posterior parietal cortex (Platt and Glimcher, 1999) is also modulated by the expected value of the reward during a free-choice task.…”

Section: Neural Signals Related To Ordinal Position and Reward Expectmentioning

confidence: 99%

Behavioral Context and Coherent Oscillations in the Supplementary Motor Area

Lee¹

2004

J. Neurosci.

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Movements with similar physical characteristics can occur in various behavioral contexts, as when they are embedded in different sequences or when the expected outcomes of movements vary. Similarly, neurons in various sensory and motor structures in the brain commonly display modulations in their activity according to contextual factors, such as expected reward. Although these contextual signals must be combined with incoming sensory inputs to generate appropriate behaviors according to the animal's motivational state, the mechanisms by which these two signals are integrated remain poorly understood. The present study examined the effects of contextual factors on the magnitude of coherent oscillations in the activity of individual neurons recorded in the supplementary motor area (SMA) of monkeys during a serial reaction time task. In this task, the animal produced a predictable sequence of hand movements repeatedly according to visual instructions. The performance of the animal was influenced by the location of the rewarded target as well as the ordinal position of the movement. In contrast, the level of coherent oscillations in the activity of SMA neurons was affected only by the rewarded target location but not by the ordinal position of the movement sequence. In addition, changes in coherent oscillations were not accounted for by systematic changes in the mean firing rates. These results are consistent with the proposal that synchronous spikes might be used to control the flow of information and suggest that coherent oscillations in the SMA might encode contextual variables, such as expected reward.

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Relationship between mass transport and the quality of cured hide

2009

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The advantages of mathematical simulations of the process of cured hide desalination are presented. Full three-dimensional model is presented and then its one-dimensional and a two-dimensional special cases are considered and compared. In the case of one-dimensional approximation, the solution can be obtained in an analytic form, while for the two-dimensional case only numerical solution is available. A possible occurrence of a concentration shock is modelled, and a method of its prevention is proposed to reduce losses in the hide substance. The predictions of the mathematical model are then compared with experimental data and found to be in good agreement.On présente les avantages des simulations mathématiques du procédé de dessalement de peau saumurée. Un modèle tridimensionnel complet est présenté, puis les cas spéciaux unidimensionnels et bidimensionnels sont considérés et comparés. Dans le cas d'une approximation unidimensionnelle, la solution peutêtre obtenue sous une forme analytique, alors que dans le cas bidimensionnel, seule une solution numérique est disponible. Une occurrence possible d'un choc de concentration est modélisée et une méthode de prévention est proposée afin de réduire les pertes de substance dans la peau. Les prédictions du modèle mathématique sont ensuite comparées aux données expérimentales et un bon accord aété trouvé.

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Context Dependency in the Globus Pallidus Internal Segment During Targeted Arm Movements

Cited by 42 publications

References 29 publications

Signaling patterns of globus pallidus internal segment neurons during forearm rotation

Signaling patterns of globus pallidus internal segment neurons during forearm rotation

Behavioral Context and Coherent Oscillations in the Supplementary Motor Area

Relationship between mass transport and the quality of cured hide

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