scholarly journals Imaging neural activity in the ventral nerve cord of behaving adult Drosophila

2018 ◽  
Author(s):  
Chin-Lin Chen ◽  
Laura Hermans ◽  
Meera C. Viswanathan ◽  
Denis Fortun ◽  
Michael Unser ◽  
...  

AbstractTo understand neural circuits that control limbs, one must measure their activity during behavior. Until now this goal has been challenging, because the portion of the nervous system that contains limb premotor and motor circuits is largely inaccessible to large-scale recording techniques in intact, moving animals – a constraint that is true for both vertebrate and invertebrate models. Here, we introduce a method for 2-photon functional imaging from the ventral nerve cord of behaving adult Drosophila melanogaster. We use this method to reveal patterns of activity across nerve cord populations during grooming and walking and to uncover the functional encoding of moonwalker ascending neurons (MANs), moonwalker descending neurons (MDNs), and a novel class of locomotion-associated descending neurons. This new approach enables the direct investigation of circuits associated with complex limb movements.

2021 ◽  
Author(s):  
Pavan Ramdya ◽  
Laura Hermans ◽  
Murat Kaynak ◽  
Jonas Braun ◽  
Victor Lobato-Rios ◽  
...  

The dynamics and connectivity of neural circuits continuously change during an animal's lifetime on timescales ranging from milliseconds to days. Therefore, to investigate how biological networks accomplish remarkable cognitive and behavioral tasks, minimally invasive methods are needed to perform repeated measurements, or perturbations of neural circuits in behaving animals across time. Such tools have been developed to investigate the brain but similar approaches are lacking for comprehensively and repeatedly recording motor circuits in behaving animals. Here we describe a suite of microfabricated technologies that enable long-term, minimally invasive optical recordings of the adult Drosophila melanogaster ventral nerve cord (VNC)---neural tissues that are functionally equivalent to the vertebrate spinal cord. These tools consist of (i) a manipulator arm that permits the insertion of (ii) a compliant implant into the thorax to expose the imaging region of interest; (iii) a numbered, transparent polymer window that encloses and provides optical access to the inside of the thorax, and (iv) a hinged remounting stage that allows gentle and repeated tethering of an implanted animal for two-photon imaging. We validate and illustrate the utility of our toolkit in several ways. First, we show that the thoracic implant and window have minimal impact on animal behavior and survival while also enabling neural recordings from individual animals across at least one month. Second, we follow the degradation of chordotonal organ mechanosensory nerve terminals in the VNC over weeks after leg amputation. Third, because our tools allow recordings of the VNC with the gut intact, we discover waves of neural population activity following ingestion of a high-concentration caffeine solution. In summary, our microfabricated toolkit makes it possible to longitudinally monitor anatomical and functional changes in premotor and motor neural circuits, and more generally opens up the long-term investigation of thoracic tissues.


2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Chin-Lin Chen ◽  
Laura Hermans ◽  
Meera C. Viswanathan ◽  
Denis Fortun ◽  
Florian Aymanns ◽  
...  

2020 ◽  
Author(s):  
Aaron M Allen ◽  
Megan C Neville ◽  
Sebastian Birtles ◽  
Vincent Croset ◽  
Christoph Daniel Treiber ◽  
...  

Author(s):  
Roy J. Baerwald ◽  
Lura C. Williamson

In arthropods the perineurium surrounds the neuropile, consists of modified glial cells, and is the morphological basis for the blood-brain barrier. The perineurium is surrounded by an acellular neural lamella, sometimes containing scattered collagen-like fibrils. This perineurial-neural lamellar complex is thought to occur ubiquitously throughout the arthropods. This report describes a SEM and TEM study of the sheath surrounding the ventral nerve cord of Panulirus argus.Juvenile P. argus were collected from the Florida Keys and maintained in marine aquaria. Nerve cords were fixed for TEM in Karnovsky's fixative and saturated tannic acid in 0.1 M Na-cacodylate buffer, pH = 7.4; post-fixed in 1.0% OsO4 in the same buffer; dehydrated through a graded series of ethanols; embedded in Epon-Araldite; and examined in a Philips 200 TEM. Nerve cords were fixed for SEM in a similar manner except that tannic acid was not used.


Author(s):  
V. Skibchyk ◽  
V. Dnes ◽  
R. Kudrynetskyi ◽  
O. Krypuch

Аnnotation Purpose. To increase the efficiency of technological processes of grain harvesting by large-scale agricultural producers due to the rational use of combine harvesters available on the farm. Methods. In the course of the research the methods of system analysis and synthesis, induction and deduction, system-factor and system-event approaches, graphic method were used. Results. Characteristic events that occur during the harvesting of grain crops, both within a single production unit and the entire agricultural producer are identified. A method for predicting time intervals of use and downtime of combine harvesters of production units has been developed. The roadmap of substantiation the rational seasonal scenario of the use of grain harvesters of large-scale agricultural producers is developed, which allows estimating the efficiency of each of the scenarios of multivariate placement of grain harvesters on fields taking into account influence of natural production and agrometeorological factors on the efficiency of technological cultures. Conclusions 1. Known scientific and methodological approaches to optimization of machine used in agriculture do not take into account the risks of losses of crops due to late harvesting, as well as seasonal natural and agrometeorological conditions of each production unit of the farmer, which requires a new approach to the rational use of rational seasonal combines of large agricultural producers. 2. The developed new approach to the substantiation of the rational seasonal scenario of the use of combined harvesters of large-scale agricultural producers allows taking into account the costs of harvesting of grain and the cost of the lost crop because of the lateness of harvesting at optimum variants of attraction of additional free combine harvesters. provides more profit. 3. The practical application of the developed road map will allow large-scale agricultural producers to use combine harvesters more efficiently and reduce harvesting costs. Keywords: combine harvesters, use, production divisions, risk, seasonal scenario, large-scale agricultural producers.


Author(s):  
S. Pragati ◽  
S. Kuldeep ◽  
S. Ashok ◽  
M. Satheesh

One of the situations in the treatment of disease is the delivery of efficacious medication of appropriate concentration to the site of action in a controlled and continual manner. Nanoparticle represents an important particulate carrier system, developed accordingly. Nanoparticles are solid colloidal particles ranging in size from 1 to 1000 nm and composed of macromolecular material. Nanoparticles could be polymeric or lipidic (SLNs). Industry estimates suggest that approximately 40% of lipophilic drug candidates fail due to solubility and formulation stability issues, prompting significant research activity in advanced lipophile delivery technologies. Solid lipid nanoparticle technology represents a promising new approach to lipophile drug delivery. Solid lipid nanoparticles (SLNs) are important advancement in this area. The bioacceptable and biodegradable nature of SLNs makes them less toxic as compared to polymeric nanoparticles. Supplemented with small size which prolongs the circulation time in blood, feasible scale up for large scale production and absence of burst effect makes them interesting candidates for study. In this present review this new approach is discussed in terms of their preparation, advantages, characterization and special features.


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