Motor Cortical Representation of Speed and Direction During Reaching

1999 ◽  
Vol 82 (5) ◽  
pp. 2676-2692 ◽  
Author(s):  
Daniel W. Moran ◽  
Andrew B. Schwartz
Keyword(s):  
Single Cell ◽  
Muscle Activity ◽  
Cell Activity ◽  
Cortical Activity ◽  
Central Position ◽  
Electromyographic Activity ◽  
Time Varying ◽  
Preferred Direction ◽  
Single Cell Activity ◽  
Motor Cortical

The motor cortical substrate associated with reaching was studied as monkeys moved their hands from a central position to one of eight targets spaced around a circle. Single-cell activity patterns were recorded in the proximal arm area of motor cortex during the task. In addition to the well-studied average directional selectivity (“preferred direction”) of single-cell activity, we also found the time-varying speed of movement to be represented in the cortical activity. A single equation relating motor cortical discharge rate to these two parameters was developed. This equation, which has both independent (speed only) and interactive (speed and direction) components, described a large portion of the time-varying motor cortical activity during the task. Electromyographic activity from a number of upper arm muscles was recorded during this task. Muscle activity was also found to be directionally tuned; however, the distributions of preferred directions were found to be significantly different from cortical activity. In addition, the effect of speed on cortical and muscle activity was also found to be significantly different.

Distinct biogeographic patterns of bacterioplankton composition and single-cell activity between the subtropics and Antarctica

2018 ◽  
Vol 20 (8) ◽  
pp. 3100-3108 ◽  
Author(s):  
Insa Bakenhus ◽  
Leon Dlugosch ◽  
Helge-Ansgar Giebel ◽  
Christine Beardsley ◽  
Meinhard Simon ◽  
...  
Keyword(s):  
Single Cell ◽  
Cell Activity ◽  
Biogeographic Patterns ◽  
Single Cell Activity

scholarly journals Visualization is crucial for understanding microbial processes in the ocean

2019 ◽  
Vol 374 (1786) ◽  
pp. 20190083 ◽  
Author(s):  
Marta Sebastián ◽  
Josep M. Gasol
Keyword(s):  
Single Cell ◽  
Metabolic Activity ◽  
Cell Activity ◽  
Level Of Activity ◽  
Single Cell Activity ◽  
Recent Developments ◽  
Insight Into ◽  
Do So

Recent developments in community and single-cell genomic approaches have provided an unprecedented amount of information on the ecology of microbes in the aquatic environment. However, linkages between each specific microbe's identity and their in situ level of activity (be it growth, division or just metabolic activity) are much more scarce. The ultimate goal of marine microbial ecology is to understand how the environment determines the types of different microbes in nature, their function, morphology and cell-to-cell interactions and to do so we should gather three levels of information, the genomic (including identity), the functional (activity or growth), and the morphological, and for as many individual cells as possible. We present a brief overview of methodologies applied to address single-cell activity in marine prokaryotes, together with a discussion of the difficulties in identifying and categorizing activity and growth. We then provide and discuss some examples showing how visualization has been pivotal for challenging established paradigms and for understanding the role of microbes in the environment, unveiling processes and interactions that otherwise would have been overlooked. We conclude by stating that more effort should be directed towards integrating visualization in future approaches if we want to gain a comprehensive insight into how microbes contribute to the functioning of ecosystems. This article is part of a discussion meeting issue ‘Single cell ecology’.

Sign in / Sign up

Export Citation Format

Share Document