scholarly journals Spatiotemporally precise optogenetic activation of sensory neurons in freely walking Drosophila

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Brian D DeAngelis ◽  
Jacob A Zavatone-Veth ◽  
Aneysis D Gonzalez-Suarez ◽  
Damon A Clark
Keyword(s):  
Simple Method ◽  
Walking Behavior ◽  
Optogenetic Stimulation ◽  
Body Regions ◽  
Transient Activation ◽  
Limb Coordination ◽  
Side Body ◽  
Real Time Tracking ◽  
Freely Moving ◽  
Post Hoc

Previous work has characterized how walking Drosophila coordinate the movements of individual limbs (DeAngelis et al., 2019). To understand the circuit basis of this coordination, one must characterize how sensory feedback from each limb affects walking behavior. However, it has remained difficult to manipulate neural activity in individual limbs of freely moving animals. Here, we demonstrate a simple method for optogenetic stimulation with body side-, body segment-, and limb-specificity that does not require real-time tracking. Instead, we activate at random, precise locations in time and space and use post hoc analysis to determine behavioral responses to specific activations. Using this method, we have characterized limb coordination and walking behavior in response to transient activation of mechanosensitive bristle neurons and sweet-sensing chemoreceptor neurons. Our findings reveal that activating these neurons has opposite effects on turning, and that activations in different limbs and body regions produce distinct behaviors.

A (Relatively) Simple Method to Visualize Single Molecules

2011 ◽  
Vol 19 (1) ◽  
pp. 8-8
Author(s):  
Stephen W. Carmichael ◽  
Julio M. Fernandez
Keyword(s):  
Fluorescence Microscopy ◽  
Simple Technique ◽  
Zero Mode ◽  
Single Molecules ◽  
Simple Method ◽  
Expensive Equipment ◽  
Freely Moving ◽  
Good For

Fluorescence microscopy can be used to study certain single molecules in solution or attached to a surface. Two conflicting challenges to overcome are: (1) to image freely moving molecules for long times and (2) to image immobilized single molecules when there is a highly fluorescent background. The fact that these two goals are inversely related is illustrated by epifluorescence, which is good for observing freely diffusing molecules but poor for detecting single molecules, whereas the reverse is true for zero-mode waveguides. Plus, these and other techniques require elaborate (read: expensive) equipment with computerized controls. Sabrina Leslie, Alexander Fields, and Adam Cohen have developed an ingenious (relatively) simple technique that can image freely moving single molecules.

scholarly journals Ca2+ imaging of neurons in freely moving rats with automatic post hoc histological identification

2020 ◽  
Vol 341 ◽  
pp. 108765
Author(s):  
Philip Anner ◽  
Johannes Passecker ◽  
Thomas Klausberger ◽  
Georg Dorffner
Keyword(s):  
Freely Moving Rats ◽  
Freely Moving ◽  
Post Hoc

A simple method for implanting electrodes in freely moving neonatal rats

1982 ◽  
Vol 6 (1-2) ◽  
pp. 175-177 ◽  
Author(s):  
Enrico Cherubini ◽  
Maria Rita de Feo ◽  
Oriano Mecarelli ◽  
Gianfranco Ricci
Keyword(s):  
Neonatal Rats ◽  
Simple Method ◽  
Freely Moving

scholarly journals Validation of a Speed-Based Classification System Using Quantitative Measures of Walking Performance Poststroke

2008 ◽  
Vol 22 (6) ◽  
pp. 672-675 ◽  
Author(s):  
Mark G. Bowden ◽  
Chitralakshmi K. Balasubramanian ◽  
Andrea L. Behrman ◽  
Steven A. Kautz
Keyword(s):  
Classification System ◽  
Walking Speed ◽  
Step Length ◽  
Self Report ◽  
Group Differences ◽  
Community Based ◽  
Walking Behavior ◽  
Significant Difference ◽  
Walking Performance ◽  
Post Hoc

Background. For clinical trials in stroke rehabilitation, self-selected walking speed has been used to stratify persons to predict functional walking status and to define clinical meaningfulness of changes. However, this stratification was validated primarily using self-report questionnaires. Objective. This study aims to validate the speed-based classification system with quantitative measures of walking performance. Methods. A total of 59 individuals who had hemiparesis for more than 6 months after stroke participated in this study. Spatiotemporal and kinetic measures included the percentage of total propulsion generated by the paretic leg (Pp), the percentage of the stride length accounted for by the paretic leg step length (PSR), and the percentage of the gait cycle spent in paretic preswing (PPS). Additional measures included the synergy portion of the Fugl-Meyer Assessment and the average number of steps/day in the home and community measured with a step activity monitor. Participants were stratified by self-selected gait speed into 3 groups: household (<0.4 m/s), limited community (0.4-0.8 m/s), and community (>0.8 m/s) ambulators. Group differences were analyzed using a Kruskal—Wallis H test with rank sums test post hoc analyses. Results. Analyses demonstrated a main effect in all measures, but only steps/day and PPS demonstrated a significant difference between all 3 groups. Conclusions. Classifying individuals poststroke by self-selected walking speed is associated with home and community-based walking behavior as quantified by daily step counts. In addition, PPS distinguishes all 3 groups. Pp differentiates the moderate from the fast groups and may represent a contribution to mechanisms of increasing walking speed. Speed classification presents a useful yet simple mechanism to stratify subjects poststroke and may be mechanically linked to changes in PPS.

scholarly journals SkinnerTrax: high-throughput behavior-dependent optogenetic stimulation of Drosophila

2017 ◽  
Author(s):  
Ulrich Stern ◽  
Chung-Hui Yang
Keyword(s):  
High Throughput ◽  
Closed Loop ◽  
Optogenetic Stimulation ◽  
Cns Neurons ◽  
Highly Effective ◽  
Freely Moving ◽  
Stimulation Of

AbstractWhile red-shifted channelrhodopsin has been shown to be highly effective in activating CNS neurons in freely moving Drosophila, there were no existing high-throughput tools for closed-loop, behavior-dependent optogenetic stimulation of Drosophila. Here, we present SkinnerTrax to fill this void. SkinnerTrax stimulates individual flies promptly in response to their being at specific positions or performing specific actions. Importantly, SkinnerTrax was designed for and achieves significant throughput with simple and inexpensive components.

HSP70 accumulation in tissues of heat-stressed rats is blunted with advancing age

1995 ◽  
Vol 79 (5) ◽  
pp. 1673-1678 ◽  
Author(s):  
K. C. Kregel ◽  
P. L. Moseley ◽  
R. Skidmore ◽  
J. A. Gutierrez ◽  
V. Guerriero
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Matched Control ◽  
Control Group ◽  
Fischer 344 Rats ◽  
Fischer 344 ◽  
Freely Moving ◽  
Colonic Temperature ◽  
Post Hoc

To determine whether aging results in reduced accumulation of the 70-kDa heat shock protein (HSP70) in response to a thermal challenge, experiments were conducted in conscious and freely moving mature (12-mo-old) and senescent (24-mo-old) male Fischer 344 rats. Rats were assigned to a euthermic control group or a nonexertionally heated group that was exposed to an ambient temperature of 42 degrees C until colonic temperature reached 41 degrees C. Samples were subsequently obtained from the liver and myocardium, and absolute levels of both the constitutive and inducible forms of HSP70 were quantitated. Heat-stressed rats had significantly elevated HSP70 levels in the liver compared with the euthermic groups. Post hoc comparisons revealed that heat stress elicited marked elevations in liver HSP70 in mature rats compared with age-matched control animals. In contrast, HSP70 values were unchanged in the senescent heated group vs. the control group. In the myocardium, heat stress produced marked increases in HSP70 levels in both the mature and senescent groups compared with age-matched control animals, with accumulation significantly blunted in the senescent vs. mature rats. Thus the increases in liver and myocardial HSP70 accumulation in response to nonexertional heat stress are attenuated with senescence. Because these proteins are postulated to protect cells from injury and enhance cellular recovery from heat stress, the data suggest that an aging organism has a reduced ability to properly maintain cellular function and integrity after a thermal challenge.

A simple method for measuring EEG in freely moving guinea pigs

2001 ◽  
Vol 107 (1-2) ◽  
pp. 125-130 ◽  
Author(s):  
H Mumford ◽  
J.R Wetherell
Keyword(s):  
Guinea Pigs ◽  
Simple Method ◽  
Freely Moving

scholarly journals Transient effect of mossy fiber stimulation on spatial firing of CA3 neurons

2018 ◽  
Author(s):  
Joonyeup Lee ◽  
Miru Yun ◽  
Eunjae Cho ◽  
Jong Won Lee ◽  
Doyun Lee ◽  
...  
Keyword(s):  
Mossy Fiber ◽  
Empirical Test ◽  
Mossy Fibers ◽  
Transient Effect ◽  
Optogenetic Stimulation ◽  
Place Fields ◽  
Freely Moving ◽  
Ca3 Neurons ◽  
Fiber Stimulation ◽  
Stimulation Of

AbstractStrong hippocampal mossy fiber synapses are thought to function as detonators, imposing ‘teaching’ signals onto CA3 neurons during new memory formation. For an empirical test of this long-standing view, we examined effects of stimulating mossy fibers on spatial firing of CA3 neurons in freely-moving mice. We found that optogenetic stimulation of mossy fibers can alter CA3 spatial firing, but their effects are only transient. Spatially restricted mossy fiber stimulation, either congruent or incongruent with CA3 place fields, was more likely to suppress than enhance CA3 neuronal activity. Also, changes in spatial firing induced by optogenetic stimulation reverted immediately upon stimulation termination, leaving CA3 place fields unaltered. Our results do not support the traditional view that mossy fibers impose teaching signals onto CA3 network, and show robustness of established CA3 spatial representations.

scholarly journals Wireless Battery Free Fully Implantable Multimodal Recording and Neuromodulation Tools for Songbirds

2020 ◽  
Author(s):  
Jokubas Ausra ◽  
Stephanie Munger ◽  
Amirhossein Azami ◽  
Alex Burton ◽  
Roberto Peralta ◽  
...  
Keyword(s):  
Energy Management ◽  
Antenna Design ◽  
Full Potential ◽  
Light Weight ◽  
Minimal Impact ◽  
Optogenetic Stimulation ◽  
Physiological Recording ◽  
Small Footprint ◽  
Freely Moving

Abstract Wireless battery free and fully implantable tools for the interrogation of the central and peripheral nervous system have quantitively expanded the capabilities to study mechanistic and circuit level behavior in freely moving rodents. The light weight and small footprint of such devices enables fully subdermal implantation that results in the capability to perform studies with minimal impact on subject behavior and yields broad application in a range of experimental paradigms. While these advantages have been successfully proven in rodents that move predominantly in 2D the full potential of a wireless and battery free device can be harnessed with species that move in 3D, where interrogation with tethered devices is very difficult or impossible. Here we report on a wireless, battery free and multimodal platform that enables optogenetic stimulation and physiological recording in a highly miniaturized form factor for use in songbirds. The systems are enabled by behavior guided primary antenna design and advanced energy management to ensure stable optogenetic stimulation and physiological recording throughout 3D experimental arenas. Collectively, these design approaches quantitatively expand the use of wireless subdermally implantable neuromodulation and sensing tools to species previously excluded from in vivo real time experiments.

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