Synchronization patterns suggest different functional organization in parietal reach region and dorsal premotor cortex

The parietal reach region (PRR) and dorsal premotor cortex (PMd) form part of the fronto-parietal reach network. While neural selectivity profiles of single-cell activity in these areas can be remarkably similar, other data suggest that both areas serve different computational functions in visually guided reaching. Here we test the hypothesis that different neural functional organizations characterized by different neural synchronization patterns might be underlying the putatively different functional roles. We use cross-correlation analysis on single-unit activity (SUA) and multiunit activity (MUA) to determine the prevalence of synchronized neural ensembles within each area. First, we reliably find synchronization in PRR but not in PMd. Second, we demonstrate that synchronization in PRR is present in different cognitive states, including “idle” states prior to task-relevant instructions and without neural tuning. Third, we show that local field potentials (LFPs) in PRR but not PMd are characterized by an increased power and spike field coherence in the beta frequency range (12–30 Hz), further indicating stronger synchrony in PRR compared with PMd. Finally, we show that neurons with similar tuning properties tend to be correlated in their random spike rate fluctuations in PRR but not in PMd. Our data support the idea that PRR and PMd, despite striking similarity in single-cell tuning properties, are characterized by unequal local functional organization, which likely reflects different network architectures to support different functional roles within the fronto-parietal reach network.

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Rule Activity Related to Spatial and Numerical Magnitudes: Comparison of Prefrontal, Premotor, and Cingulate Motor Cortices

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00545 ◽

2014 ◽

Vol 26 (5) ◽

pp. 1000-1012 ◽

Cited By ~ 5

Author(s):

Anne-Kathrin Eiselt ◽

Andreas Nieder

Keyword(s):

Motor Cortex ◽

Single Cell ◽

Frontal Lobe ◽

Premotor Cortex ◽

Cell Activity ◽

Dorsal Premotor Cortex ◽

Single Cell Activity ◽

Numerical Magnitudes ◽

Abstract Level

In everyday situations, quantitative rules, such as “greater than/less than,” need to be applied to a multitude of magnitude comparisons, be they sensory, spatial, temporal, or numerical. We have previously shown that rules applied to different magnitudes are encoded in the lateral PFC. To investigate if and how other frontal lobe areas also contribute to the encoding of quantitative rules applied to multiple magnitudes, we trained monkeys to switch between “greater than/less than” rules applied to either line lengths (spatial magnitudes) or dot numerosities (discrete numerical magnitudes). We recorded single-cell activity from the dorsal premotor cortex (dPMC) and cingulate motor cortex (CMA) and compared it with PFC activity. We found the largest proportion of quantitative rule-selective cells in PFC (24% of randomly selected cells), whereas neurons in dPMC and CMA rarely encoded the rule (6% of the cells). In addition, rule selectivity of individual cells was highest in PFC neurons compared with dPMC and CMA neurons. Rule-selective neurons that simultaneously represented the “greater than/less than” rules applied to line lengths and numerosities (“rule generalists”) were exclusively present in PFC. In dPMC and CMA, however, neurons primarily encoded rules applied to only one of the two magnitude types (“rule specialists”). Our data suggest a special involvement of PFC in representing quantitative rules at an abstract level, both in terms of the proportion of neurons engaged and the coding capacities.

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Modest Gaze-Related Discharge Modulation in Monkey Dorsal Premotor Cortex During a Reaching Task Performed With Free Fixation

Journal of Neurophysiology ◽

10.1152/jn.00995.2001 ◽

2002 ◽

Vol 88 (2) ◽

pp. 1064-1072 ◽

Cited By ~ 41

Author(s):

Paul Cisek ◽

John F. Kalaska

Keyword(s):

Premotor Cortex ◽

Cell Activity ◽

Delay Period ◽

Gaze Direction ◽

Dorsal Premotor Cortex ◽

Experimental Conditions ◽

Reaching Task ◽

Oculomotor Behavior ◽

Arm Reaching ◽

Gaze Angle

Recent studies have shown that gaze angle modulates reach-related neural activity in many cortical areas, including the dorsal premotor cortex (PMd), when gaze direction is experimentally controlled by lengthy periods of imposed fixation. We looked for gaze-related modulation in PMd during the brief fixations that occur when a monkey is allowed to look around freely without experimentally imposed gaze control while performing a center-out delayed arm-reaching task. During the course of the instructed-delay period, we found significant effects of gaze angle in 27–51% of PMd cells. However, for 90–95% of cells, these effects accounted for <20% of the observed discharge variance. The effect of gaze was significantly weaker than the effect of reach-related variables. In particular, cell activity during the delay period was more strongly related to the intended movement expressed in arm-related coordinates than in gaze-related coordinates. Under the same experimental conditions, many cells in medial parietal cortex exhibited much stronger gaze-related modulation and expressed intended movement in gaze-related coordinates. In summary, gaze direction-related modulation of cell activity is indeed expressed in PMd during the brief fixations that occur in natural oculomotor behavior, but its overall effect on cell activity is modest.

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Monkey primary motor and premotor cortex: single-cell activity related to prior information about direction and extent of an intended movement

Journal of Neurophysiology ◽

10.1152/jn.1989.61.3.534 ◽

1989 ◽

Vol 61 (3) ◽

pp. 534-549 ◽

Cited By ~ 290

Author(s):

A. Riehle ◽

J. Requin

Keyword(s):

Reaction Time ◽

Single Cell ◽

Prior Information ◽

Movement Time ◽

Premotor Cortex ◽

Cell Activity ◽

Visual Signal ◽

Movement Direction ◽

Wrist Flexion ◽

Movement Parameters

1. This study was devoted to the neuronal processes underlying the construction of the motor program. Two monkeys were trained in a choice reaction time task to perform precise wrist flexion and extension movements of small and large extent. During a trial, the first visual signal, the preparatory signal (PS), informed the animal completely, partially, or not at all about direction and/or extent of the forthcoming movement. After a constant waiting period, a second visual signal, the response signal (RS), was illuminated calling for execution of the requested movement. 2. Reaction time (RT) and movement time (MT) measurements during the training as well as the recording sessions revealed that providing prior information about movement parameters strongly affected RT, but only slightly affected MT. Reaction time decreased in relation to the amount (number of movement parameters precued) and the type of prior information. Providing information about movement direction shortened RT much more than providing information about movement extent. Behavioral data support a parametric conception of motor programming, i.e., that the programming of the different movement parameters results from assembling separate processes of different duration. These results are compatible with the model in which programming processes are serially and hierachically ordered, movement direction being processed before movement extent. 3. Single-cell recording techniques were used to study neuronal activity of the primary motor (MI) and the premotor (PM) cortex, contralateral to the active arm. The activity of 155 neurons of MI and 158 neurons of PM was recorded during performance of the task. Of these 313 neurons, only 14 neurons did not change their activity during execution of the task. Two hundred and seven neurons whose activity changes were related to movement direction and/or movement extent have been selected for the further study. They were classified into three main groups: 1) execution-related neurons (49 in MI, 27 in PM), 2) preparation- and execution-related neurons (48 in MI, 54 in PM), and 3) preparation-related neurons (8 in MI, 21 in PM). 4. Directionally selective, execution-related neurons were found to be more frequently located within MI (81/105, 77.1%) than within PM (55/102, 53.9%), whereas directionally selective, preparation-related neurons appeared tobe more frequently located within PM (47/102, 46.1%) than within MI (24/105, 22.9%).(ABSTRACT TRUNCATED AT 400 WORDS)

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Reaching Movements With Similar Hand Paths but Different Arm Orientations. II. Activity of Individual Cells in Dorsal Premotor Cortex and Parietal Area 5

Journal of Neurophysiology ◽

10.1152/jn.1997.78.5.2413 ◽

1997 ◽

Vol 78 (5) ◽

pp. 2413-2426 ◽

Cited By ~ 122

Author(s):

Stephen H. Scott ◽

Lauren E. Sergio ◽

John F. Kalaska

Keyword(s):

Neuronal Activity ◽

Premotor Cortex ◽

Cell Activity ◽

Reaching Movements ◽

Movement Direction ◽

Dorsal Premotor Cortex ◽

Cortical Areas ◽

Parietal Area ◽

Area 5 ◽

Interaction Term

Scott, Stephen H., Lauren E. Sergio, and John F. Kalaska. Reaching movements with similar hand paths but different arm orientations. II. Activity of individual cells in dorsal premotor cortex and parietal area 5. J. Neurophysiol. 78: 2413–2426, 1997. Neuronal activity in primary motor cortex (MI) is altered when monkeys make reaching movements along similar handpaths at shoulder level with two different arm orientations, either in the natural orientation with the elbow positioned below the level of the shoulder and hand or in an abducted orientation with the elbow abducted nearly to shoulder level. The present study examines to what degree two other cortical areas, the dorsal premotor (PMd) and parietal area 5, also show modulation of cell activity related to arm geometry during reaching. The activity of most (89%) of the 207 cells in PMd recorded while monkeys made reaching movements showed a statistically significant change in activity between orientations [analysis of variation (ANOVA), P < 0.01]. A common effect of arm orientation on cell activity was a change in the overall level of discharge either before, during, and/or after movement (67%, ANOVA, task main effect, P < 0.01). Many cells (76%) showed a statistical change in their response to movement direction (ANOVA, task × direction interaction term, P < 0.01), including changes in dynamic range and changes in the preferred direction of cells that were directionally tuned in both arm orientations. Overall, these effects were similar qualitatively but not as strong quantitatively as those observed in MI. A sample of cells was recorded in area 5 of one monkey. Most (95%) of the 79 area 5 cells showed a change in activity when reaching movements were performed using different arm orientations (ANOVA, P < 0.01). As in PMd and MI, many area 5 cells (56, 71%) showed changes in their tonic discharge before, during, and/or after movement, and 70 cells (89%) showed changes in their response to movement direction (ANOVA, task × direction interaction term, P < 0.01). The observed changes in neuronal activity related to posture and movement in MI, PMd and area 5 demonstrate that single-cell activity in these cortical areas is not simply related to the spatial attributes of hand trajectory but is also strongly influenced by attributes of movement related to arm geometry.

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Faculty Opinions recommendation of High-throughput single-cell activity-based screening and sequencing of antibodies using droplet microfluidics.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.737645825.793573778 ◽

2020 ◽

Author(s):

Stephen Nutt

Keyword(s):

Single Cell ◽

High Throughput ◽

Cell Activity ◽

Droplet Microfluidics ◽

Single Cell Activity

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Spatial and temporal extent of single-pulse TMS on single-cell activity in alert macaque monkeys

Brain Stimulation ◽

10.1016/j.brs.2017.01.479 ◽

2017 ◽

Vol 10 (2) ◽

pp. 507 ◽

Cited By ~ 1

Author(s):

M.C. Romero ◽

M. Davare ◽

P. Janssen

Keyword(s):

Single Cell ◽

Cell Activity ◽

Single Pulse ◽

Macaque Monkeys ◽

Single Cell Activity ◽

Temporal Extent

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Temporal property of single-cell activity in response to motion-defined shapes in monkey dorsal and ventral cortical areas

Neuroreport ◽

10.1097/wnr.0000000000000826 ◽

2017 ◽

Vol 28 (13) ◽

pp. 793-799 ◽

Cited By ~ 2

Author(s):

Takashi Handa ◽

Shumpei Unno ◽

Akichika Mikami

Keyword(s):

Single Cell ◽

Cell Activity ◽

Temporal Property ◽

Cortical Areas ◽

Single Cell Activity

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Interactions between pairs of transcranial magnetic stimuli over the human left dorsal premotor cortex differ from those seen in primary motor cortex

The Journal of Physiology ◽

10.1113/jphysiol.2006.123562 ◽

2007 ◽

Vol 578 (2) ◽

pp. 551-562 ◽

Cited By ~ 74

Author(s):

Giacomo Koch ◽

Michele Franca ◽

Hitoshi Mochizuki ◽

Barbara Marconi ◽

Carlo Caltagirone ◽

...

Keyword(s):

Motor Cortex ◽

Primary Motor Cortex ◽

Premotor Cortex ◽

Dorsal Premotor Cortex

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Given the importance of mTOR signaling in a number of illnesses, it looks suitable to use miR 99 family members as a therapeutic intervention to deal with these illnesses by using gene therapy tools

10.31219/osf.io/8cwgh ◽

2021 ◽

Author(s):

Moataz Dowaidar

Keyword(s):

Therapeutic Intervention ◽

Regulatory Network ◽

Immune Cell ◽

Family Members ◽

Cell Activity ◽

Mtor Signaling ◽

Critical Pathways ◽

Functional Roles ◽

Cell Life ◽

High Level

This review outlines the activities of mirR99 family members in different cancers. Though the functional roles of these miRs are well described in some malignancies, the functional functions of these family members in other forms of cancer remain uncertain. The development and use of engineered mouse models such as miR99a KO, miR100 KO, or miR99a/100 DKO mice challenged with the type or subtype of the cancer in question would be extremely beneficial in determining the physiological and pathological roles of members of this family in different types of cancer and immune cell subtypes.The miR99 family members, which include miR99a, miR99b, and miR100, are key components of a regulatory network that governs several aspects of the cell life cycle, including differentiation, metabolism, survival and death. They are involved in the deregulation of numerous critical pathways including growth factor receptors like FGFR and IGF1R, Notch, mTOR, TGFB and Wnt signaling pathways to alter cellular function. In addition, the typical miR99 target, mTOR, appears to be at the core of the regulatory network miR99, and is more commonly involved in miR99-mediated dysregulation of cell activity. Given the importance of mTOR signaling in a number of illnesses, it looks suitable to use miR99 family members as a therapeutic intervention to deal with these illnesses. mTOR depletion did not result in upregulating miR99a in OSCC cells. In addition, an aberrant activation of PI3K/AKT/mTOR signaling in AMLs, despite increased expression of miR99 family members in AMLs. All in all, this evidence alludes to the existence of an unknown mechanism that maintains mTOR activity running despite the presence in these cells of a high level of miR99 family members. Modulation of miR99 activity might be a viable method for changing the expression of Treg in autoimmune diseases.

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