scholarly journals Advantages of acute brain slices prepared at physiological temperature in characterization of synaptic functions

2019 ◽  
Author(s):  
Kohgaku Eguchi ◽  
Philipp Velicky ◽  
Elena Hollergschwandtner ◽  
Makoto Itakura ◽  
Yugo Fukazawa ◽  
...  
Keyword(s):  
Neuronal Damage ◽  
Brain Slices ◽  
Synaptic Function ◽  
Synaptic Proteins ◽  
Slice Preparation ◽  
Physiological Temperature ◽  
Synaptic Functions ◽  
Brain Slice Preparation

AbstractAcute brain slice preparation is a powerful experimental model for investigating the characteristics of synaptic function in the brain. Although brain tissue is usually cut at ice-cold temperature (CT) to facilitate slicing and avoid neuronal damage, exposure to CT causes molecular and architectural changes of synapses. To address these issues, we investigated ultrastructural and electrophysiological features of synapses in mouse acute cerebellar slices prepared at ice-cold and physiological temperature (PT). In the slices prepared at CT, we found significant spine loss and reconstruction, synaptic vesicle rearrangement and decrease in synaptic proteins, all of which were not detected in slices prepared at PT. Consistent with these structural findings, slices prepared at PT showed higher release probability and higher detectability of long-term depression after motor learning compared with slices prepared at CT. These results indicate substantial advantages of the slice preparation at PT for investigating synaptic functions in different physiological conditions.

scholarly journals Advantages of Acute Brain Slices Prepared at Physiological Temperature in the Characterization of Synaptic Functions

2020 ◽  
Vol 14 ◽  
Author(s):  
Kohgaku Eguchi ◽  
Philipp Velicky ◽  
Elena Hollergschwandtner ◽  
Makoto Itakura ◽  
Yugo Fukazawa ◽  
...  
Keyword(s):  
Brain Slices ◽  
Physiological Temperature ◽  
Synaptic Functions

Halothane-induced Dilatation of Intraparenchymal Arterioles in Rat Brain Slices 

1997 ◽  
Vol 86 (4) ◽  
pp. 885-894 ◽  
Author(s):  
Christopher P. Harkin ◽  
Antal G. Hudetz ◽  
William T. Schmeling ◽  
John P. Kampine ◽  
Neil E. Farber
Keyword(s):  
Sodium Nitroprusside ◽  
Brain Slice ◽  
Brain Slices ◽  
Resistance Index ◽  
Nitric Oxide Donor ◽  
Slice Preparation ◽  
Cerebral Microvessels ◽  
Cerebrovascular Resistance ◽  
Prostaglandin F2 Alpha ◽  
Brain Slice Preparation

Background Halothane is a potent dilator of cerebral arteries. The predominant site of cerebrovascular resistance is thought to be intracerebral arterioles, and the effects of halothane on these vessels were not previously examined. This study compared the effects of halothane with those of the vasodilator and nitric oxide donor, sodium nitroprusside, on intraparenchymal microvessel responsiveness in a brain slice preparation. Methods Anesthetized Sprague-Dawley rats underwent thoracotomy and intracardiac perfusion and then were decapitated. Hippocampal brain slices were prepared and placed in a perfusion/recording chamber and superfused with artificial cerebrospinal fluid. An arteriole was located within the brain parenchyma and its diameter was monitored with videomicroscopy before, during, and after various concentrations of halothane or sodium nitroprusside were equilibrated in the perfusate. All vessels were preconstricted with prostaglandin F2 alpha before halothane or sodium nitroprusside treatment. An observer blinded to treatment analyzed vessel diameter changes with a computerized videomicrometer. Results Baseline microvessel diameter was 18 +/- 2 microns in the halothane group (n = 14) and 15 +/- 1 microns in the sodium nitroprusside group (n = 15). Prostaglandin F2 alpha (0.5 micron) preconstricted vessels by approximately 15% from resting diameter in both groups. Halothane significantly and dose dependently dilated intracerebral microvessels by 54% +/- 6%, 74% +/- 8%, 108% +/- 13%, and 132% +/- 7% (normalized to the preconstricted diameter) at 0.5%, 1.0%, and 2.5% halothane, respectively. This dilatation corresponds to a decrease in a calculated index of cerebrovascular resistance index of up to 117% +/- 2% at 2.5% halothane. Sodium nitroprusside, in concentrations ranging from 10(-8) to 10(-3)M, also dose dependently dilated these intraparenchymal vessels by 129% +/- 7% at the highest concentration. These alterations in microvessel diameter corresponded to a decrease in the cerebrovascular resistance index of up to 116 +/- 4% for the largest dose. Conclusions Halothane produces dose-dependent vasodilatation of intraparenchymal cerebral microvessels, thus predicting marked decreases in cerebrovascular resistance in this in vitro brain slice preparation. The effects of halothane on these cerebral microvessels are similar to those of the potent vasodilator sodium nitroprusside. These findings suggest that direct effects of halathane on cerebral microvessels diameter contribute substantially to alterations in cerebrovascular resistance and flow produced by this agent.

Form follows function: actin-binding proteins as critical regulators of excitatory synapses

e-Neuroforum ◽  
2016 ◽  
Vol 22 (1) ◽  
Author(s):  
M.B Rust ◽  
K. Michaelsen-Preusse
Keyword(s):  
Binding Proteins ◽  
Brain Slices ◽  
Synaptic Function ◽  
Actin Dynamics ◽  
Actin Binding ◽  
Neuronal Cultures ◽  
Excitatory Synapses ◽  
Actin Binding Proteins ◽  
Synaptic Functions ◽  
Chemical Synapses

AbstractActin filaments (F-actin) are the major structural component of excitatory synapses. In excitatory synapses, F-actin is enriched in presynaptic terminals and in dendritic spines, and actin dynamics-the spatio-temporally controlled assembly and disassembly of F-actin-have been implicated in pre- and postsynaptic physiology. Hence, actin-binding proteins that control actin dynamics emerged as important regulators of excitatory synapses linking synaptic function and structure, and therefore they are of vital importance for behavior. By the analyses of gene-targeted mice and by loss- and gain-of-function approaches in acute brain slices or dissociated neuronal cultures, studies from the last decade, including studies from our own labs, unraveled the versatile synaptic functions for members of two important families of actin dynamics regulating proteins, namely ADF/cofilin and profilin. After a short introduction into chemical synapses and actin dynamics, we will summarize and discuss recent findings on the synaptic functions of ADF/cofilin and profilin in this review article, and we will outline future directions and perspectives in the field.

scholarly journals Metabolic changes in brain slices over time: a multiplatform metabolomics approach

2020 ◽  
Author(s):  
Carolina Gonzalez-Riano ◽  
Silvia Tapia-González ◽  
Gertrudis Perea ◽  
Candela González-Arias ◽  
Javier DeFelipe ◽  
...  
Keyword(s):  
Brain Slice ◽  
Ex Vivo ◽  
Brain Slices ◽  
Tca Cycle ◽  
Electrophysiological Recording ◽  
Slice Preparation ◽  
Experimental Conditions ◽  
The Status ◽  
The Brain ◽  
Brain Slice Preparation

ABSTRACTBrain slice preparations are widely used for research in neuroscience. However, a high-quality preparation is essential and there is no consensus regarding stable parameters that can be used to define the status of the brain slice preparation after its collection at different time points. Thus, it is critical to establish the best experimental conditions for ex-vivo studies using brain slices for electrophysiological recording. In this study, we used a multiplatform (LC-MS and GC-MS) untargeted metabolomics-based approach to shed light on the metabolome and lipidome changes induced by the brain slice preparation process. We have found significant modifications in the levels of 300 compounds, including several lipid classes and their derivatives, as well as metabolites involved in the GABAergic pathway and the TCA cycle. All these preparation-dependent changes in the brain biochemistry should be taken into consideration for future studies to facilitate non-biased interpretations of the experimental results.

scholarly journals Compartmentation of cerebral glutamate in situ as detected by 1H/13C n.m.r

1994 ◽  
Vol 298 (1) ◽  
pp. 121-127 ◽  
Author(s):  
R A Kauppinen ◽  
T R M Pirttilä ◽  
S O K Auriola ◽  
S R Williams
Keyword(s):  
Steady State ◽  
Brain Slice ◽  
Brain Slices ◽  
Slice Preparation ◽  
Total Acid ◽  
Significant Difference ◽  
13C Label ◽  
The Brain ◽  
Brain Slice Preparation

Incorporation of 13C label from either [1-13C]glucose to glutamate C-4 and lactate C-3 or from [2-13C]acetate to glutamate C-4 was monitored in situ in a superfused brain slice preparation by using 1H-detected/13C-edited (1H/13C) n.m.r. spectroscopy. The fractional enrichments of both metabolites were determined by this means in both brain slices and acid extracts of the preparations in order to assess their 1H-n.m.r. detectabilities. The 1H/13C satellite resonances from glutamate C-4 and lactate C-3 in brain tissue were followed from 4 min onwards in the presence of 5 mM [1-13C]glucose. Fractional enrichment of glutamate C-4 in the slice preparations was higher than in their acid extracts throughout the incubation of 100 min; at 30 min the enrichment was 15.9 +/- 0.6% in the slice preparations and 10.6 +/- 0.9% in extracts and at 100 min 24.5 +/- 1.7% compared with 19.7 +/- 0.4%, respectively. In contrast, lactate C-3 reached a steady-state fractional enrichment of approx. 43% by 15 min and there was no difference between the values determined in the slice preparations and the acid extracts. There was a significant difference between the glutamate C-4 fractional enrichments in the brain slices (7.4 +/- 0.6%) and extracts (5.1 +/- 0.3%) after 60 min of incubation with [2-13C]acetate. Thus 13C label from both glucose and exogenous acetate enters a pool of glutamate that is more amenable to 1H n.m.r. detection than total acid-extracted brain biochemical glutamate, whereas lactate is labelled with full 1H n.m.r. visibility. The results are discussed in the light of the biochemical factors that affect glutamate 1H-n.m.r. susceptibility and thus its n.m.r. visibility.

Oxygen treatment after perinatal hypoxia-ischemia reduces neuronal damage at short survival times, but worsens injury with long-term survival

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S444-S444 ◽  
Author(s):  
Kristin M Noppens ◽  
J Regino Perez-Polo ◽  
David K Rassin ◽  
Karin N Westlund ◽  
Roderic Fabian ◽  
...  
Keyword(s):  
Neuronal Damage ◽  
Perinatal Hypoxia ◽  
Survival Times ◽  
Term Survival ◽  
Long Term Survival ◽  
Short Survival ◽  
Oxygen Treatment ◽  
Hypoxia Ischemia

scholarly journals Characterization of Highly Irradiated ALPIDE Silicon Sensors

Universe ◽  
2019 ◽  
Vol 5 (4) ◽  
pp. 91
Author(s):  
Valentina Raskina ◽  
Filip Křížek
Keyword(s):  
Nuclear Physics ◽  
Detection Efficiency ◽  
Tracking System ◽  
Physics Institute ◽  
Total Ionization ◽  
Silicon Sensors ◽  
Active Pixel ◽  
Academy Of Sciences

The ALICE (A Large Ion Collider Experiment) experiment at CERN will upgrade its Inner Tracking System (ITS) detector. The new ITS will consist of seven coaxial cylindrical layers of ALPIDE silicon sensors which are based on Monolithic Active Pixel Sensor (MAPS) technology. We have studied the radiation hardness of ALPIDE sensors using a 30 MeV proton beam provided by the cyclotron U-120M of the Nuclear Physics Institute of the Czech Academy of Sciences in Řež. In this paper, these long-term measurements will be described. After being irradiated up to the total ionization dose 2.7 Mrad and non-ionizing energy loss 2.7 × 10 13 1 MeV n eq · cm - 2 , ALPIDE sensors fulfill ITS upgrade project technical design requirements in terms of detection efficiency and fake-hit rate.

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