Contributions of Parietal Cortex to the Working Memory of an Obstacle Acquired Visually or Tactilely in the Locomoting Cat

Wong, Carmen; Pearson, K. G.; Lomber, Stephen G.

doi:10.1093/cercor/bhx186

Cited by 20 publications

(17 citation statements)

References 55 publications

(68 reference statements)

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“…However, neurons exhibiting sustained delay period modulation represent a specialized subset of area 5 neurons capable of maintaining stable representations of obstacle infor-mation in WM. As previous work demonstrated WM deficits precluding successful avoidance when a comparable region of area 5 was deactivated [9,10,28], neurons capable of stable WM maintenance are most likely necessary for such behaviors.…”

Section: Discussionmentioning

confidence: 87%

“…During this time, the obstacle was covertly removed from the walkway before locomotion resumed. In comparison to obstacle-absent trials (OA), elevated hindleg stepping observed during OP continuation demonstrated the ability of animals to remember the obstacle over which the forelegs stepped ( Figure 1B) [4,8,9].…”

Section: Modulated Ppc Activity During Wm-guided Obstacle Negotiationmentioning

confidence: 98%

“…To assess the neural correlates of this behavior, 32-channel floating microelectrode arrays (electrode lengths: 0.9-1.5 mm) were chronically implanted in the same region of area 5 that, when deactivated, elicits WM deficits (Figures 1C and 1D) [9,10,28]. One array was placed in area 5 of each hemisphere for both animals.…”

Section: Modulated Ppc Activity During Wm-guided Obstacle Negotiationmentioning

confidence: 99%

“…Previous studies suggest that area 5 contributes similarly to WM for both visually dependent and visually independent (tactilemediated) obstacle locomotion [9]. Therefore, neural activity was subsequently compared between visual and tactile obstacle memory tasks to assess the sensory specificity of obstacle modulation.…”

Section: Sensory-specific Obstacle Modulation Was Attenuated Across Tmentioning

confidence: 99%

“…When walking resumes, elevated hindleg stepping observed even after delays tested up to 10 min demonstrates a robust, long-lasting WM of the obstacle used to guide hindleg clearance. We previously used cooling-induced cortical deactivations [7,8] to demonstrate the role of the posterior parietal cortex (PPC) in this WM-guided behavior [9,10]. When deactivations are temporally restricted to the delay during which obstacle information must be retained, WM deficits precluding successful obstacle avoidance implicates parietal area 5 in WM maintenance.…”

Section: Introductionmentioning

confidence: 99%

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Stable Delay Period Representations in the Posterior Parietal Cortex Facilitate Working-Memory-Guided Obstacle Negotiation

Wong

Lomber

2019

Current Biology

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Highlights d Parietal cortex activity is modulated when hindleg obstacle clearance is delayed d Information about the obstacle and foreleg clearance is stored in working memory d This information is recalled later in the delay to guide hindleg clearance d Sustained delay period activity maintains this information stably in working memory Authors Carmen Wong, Stephen G. Lomber Correspondence steve.lomber@uwo.ca In BriefWong and Lomber characterize the neural correlates of working memory involved in quadrupedal obstacle locomotion. When obstacle clearance is delayed, neurons within parietal area 5 of the cat retain obstacle-related information in order to guide hindleg stepping over the remembered obstacle once walking resumes. SUMMARYIn complex environments, information about surrounding obstacles is stored in working memory (WM) and used to coordinate appropriate movements for avoidance. In quadrupeds, this WM system is particularly important for guiding hindleg stepping, as an animal can no longer see the obstacle underneath the body following foreleg clearance. Such obstacle WM involves the posterior parietal cortex (PPC), as deactivation of area 5 incurs WM deficits, precluding successful avoidance. However, the neural underpinnings of this involvement remain undefined. To reveal the neural substrates of this behavior, microelectrode arrays were implanted to record neuronal activity in area 5 during an obstacle WM task in cats. Early in the WM delay, neurons were modulated generally by obstacle presence or more specifically in relation to foreleg step height. Thus, information about the obstacle or about foreleg clearance can be retained in WM. In a separate set of neurons, this information was recalled later in the delay in order to plan subsequent hindleg stepping. Such early and late delay period signals were temporally bridged by neurons exhibiting obstacle-modulated activity sustained throughout the delay. These neurons represented a specialized subset of all recorded neurons, which maintained stable information coding across the WM delay. Ultimately, these various patterns of task-related modulation enable stable representations of obstacle-related information within the PPC to support successful WM-guided obstacle negotiation in the cat.

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Section: Discussionmentioning

confidence: 87%

Section: Modulated Ppc Activity During Wm-guided Obstacle Negotiationmentioning

confidence: 98%

Section: Modulated Ppc Activity During Wm-guided Obstacle Negotiationmentioning

confidence: 99%

Section: Sensory-specific Obstacle Modulation Was Attenuated Across Tmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Stable Delay Period Representations in the Posterior Parietal Cortex Facilitate Working-Memory-Guided Obstacle Negotiation

Wong

Lomber

2019

Current Biology

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Early adversity and brain response to faces in young adulthood

et al. 2017

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Early stressors play a key role in shaping interindividual differences in vulnerability to various psychopathologies, which according to the diathesis-stress model might relate to the elevated glucocorticoid secretion and impaired responsiveness to stress. Furthermore, previous studies have shown that individuals exposed to early adversity have deficits in emotion processing from faces. This study aims to explore whether early adversities associate with brain response to faces and whether this association might associate with the regional variations in mRNA expression of the glucocorticoid receptor gene (NR3C1). A total of 104 individuals drawn from the Northern Finland Brith Cohort 1986 participated in a face-task functional magnetic resonance imaging (fMRI) study. A large independent dataset (IMAGEN, N = 1739) was utilized for reducing fMRI data-analytical space in the NFBC 1986 dataset. Early adversities were associated with deviant brain response to fearful faces (MANCOVA, P = 0.006) and with weaker performance in fearful facial expression recognition (P = 0.01). Glucocorticoid receptor gene expression (data from the Allen Human Brain Atlas) correlated with the degree of associations between early adversities and brain response to fearful faces (R = 0.25, P = 0.01) across different brain regions. Our results suggest that early adversities contribute to brain response to faces and that this association is mediated in part by the glucocorticoid system. Hum Brain Mapp 38:4470-4478, 2017. © 2017 Wiley Periodicals, Inc.

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Failures in adaptive locomotion: trial-and-error exploration to determine adequate foot elevation over obstacles

Heijnen

Rietdyk

2017

Exp Brain Res

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Lifting the limb sufficiently to clear an obstacle seems like a straightforward task, yet trips are a common cause of falls across all ages. Examination of obstacle contacts in the lab revealed a progressive decrease in foot elevation with repeated exposures, ultimately resulting in failure (Heijnen et al. Exp Brain Res 23:219-231, 2012). The purpose of this study was to determine if the progressive decrease in foot elevation continued when knowledge of obstacle contact was removed. Twenty-one young adults (mean 20.0 ± 1.0 years; 8 males) crossed a 20 cm obstacle in a 12 m walkway for 150 trials. The obstacle was covertly lowered between the lead and trail limb crossing of the obstacle, which eliminated obstacle contact with the trail limb if the limb was too low. The average failure rate was 8%, substantially higher than the 1-2% observed for stationary, visible obstacles. Therefore, tactile information from obstacle contact was instrumental for guiding the trail limb; visual information and joint angle information were insufficient for most participants. Foot elevation change over successive trials varied across participants, and was categorized as (1) asymptotic decrease (N = 11, 52%), with foot elevation converging to obstacle height, (2) linear decrease (N = 7, 33%), and (3) stable (N = 3, 14%). The asymptotic and stable groups appeared to have reasonable knowledge of obstacle height; the linear group did not. The asymptotic behavior is consistent with participants exploring the region above the obstacle through trial-and-error to determine appropriate foot elevation.

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Contributions of Parietal Cortex to the Working Memory of an Obstacle Acquired Visually or Tactilely in the Locomoting Cat

Cited by 20 publications

References 55 publications

Stable Delay Period Representations in the Posterior Parietal Cortex Facilitate Working-Memory-Guided Obstacle Negotiation

Stable Delay Period Representations in the Posterior Parietal Cortex Facilitate Working-Memory-Guided Obstacle Negotiation

Early adversity and brain response to faces in young adulthood

Failures in adaptive locomotion: trial-and-error exploration to determine adequate foot elevation over obstacles

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