scholarly journals Activity dynamics of amygdala GABAergic neurons during cataplexy of narcolepsy

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Ying Sun ◽  
Carlos Blanco-Centurion ◽  
Emmaline Bendell ◽  
Aurelio Vidal-Ortiz ◽  
Siwei Luo ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Direct Evidence ◽  
Calcium Transient ◽  
Gabaergic Neurons ◽  
Predator Odor ◽  
Central Nucleus ◽  
Time Dynamic ◽  
Imaging Tool ◽  
Neuronal Groups ◽  
Deep Brain

Recent studies showed activation of the GABAergic neurons in the central nucleus of the amygdala (CeA) triggered cataplexy of sleep disorder narcolepsy. However, there is still no direct evidence on CeA GABAergic neurons’ real-time dynamic during cataplexy. We used a deep brain calcium imaging tool to image the intrinsic calcium transient as a marker of neuronal activity changes in the narcoleptic VGAT-Cre mice by expressing the calcium sensor GCaMP6 into genetically defined CeA GABAergic neurons. Two distinct GABAergic neuronal groups involved in cataplexy were identified: spontaneous cataplexy-ON and predator odor-induced cataplexy-ON neurons. Majority in the latter group were inactive during regular sleep/wake cycles but were specifically activated by predator odor and continued their intense activities into succeeding cataplexy bouts. Furthermore, we found that CeA GABAergic neurons became highly synchronized during predator odor-induced cataplexy. We suggest that the abnormal activation and synchronization of CeA GABAergic neurons may trigger emotion-induced cataplexy.

scholarly journals Targeted esterase-induced dye (TED) loading supports direct calcium imaging in eukaryotic cell-free systems

RSC Advances ◽  
2021 ◽  
Vol 11 (27) ◽  
pp. 16285-16296
Author(s):  
Priyavathi Dhandapani ◽  
Srujan Kumar Dondapati ◽  
Anne Zemella ◽  
Dennis Bräuer ◽  
Doreen Anja Wüstenhagen ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Ion Channels ◽  
Calcium Imaging ◽  
Eukaryotic Cell ◽  
Free Protein ◽  
Imaging Tool ◽  
Key Enzyme ◽  
Cell Free Protein Synthesis

Carboxylesterase, the key enzyme to handle ester-based dyes, is synthesized in microsomes using eukaryotic cell-free protein synthesis platform and established as a viable calcium imaging tool to analyze native and cell-free synthesized ion channels.

scholarly journals Deep brain stimulation in the central nucleus of the amygdala decreases ‘wanting’ and ‘liking’ of food rewards

2016 ◽  
Vol 44 (7) ◽  
pp. 2431-2445 ◽  
Author(s):  
Shani E. Ross ◽  
Emily Lehmann Levin ◽  
Christy A. Itoga ◽  
Chelsea B. Schoen ◽  
Romeissa Selmane ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Central Nucleus ◽  
Deep Brain

scholarly journals Avoidance response to CO2 in the lateral horn

2018 ◽  
Author(s):  
Nélia Varela ◽  
Miguel Gaspar ◽  
Sophie Dias ◽  
Maria Luísa Vasconcelos
Keyword(s):  
Calcium Imaging ◽  
Mushroom Body ◽  
Antennal Lobe ◽  
Functional Role ◽  
Direct Evidence ◽  
Physiological Responses ◽  
Lateral Horn ◽  
The One ◽  
The Brain

ABSTRACTIn flies, the olfactory information is carried from the first relay in the brain, the antennal lobe, to the mushroom body (MB) and the lateral horn (LH). Olfactory associations are formed in the MB. The LH was ascribed a role in innate responses based on the stereotyped connectivity with the antennal lobe, stereotyped physiological responses to odors and MB silencing experiments. Direct evidence for the functional role of the LH is still missing. Here we investigate the behavioral role of the LH neurons directly, using the CO2 response as a paradigm. Our results show the involvement of the LH in innate responses. Specifically, we demonstrate that activity in two sets of neurons is required for the full behavioral response to CO2. Using calcium imaging we observe that the two sets of neurons respond to CO2 in different manners. Using independent manipulation and recording of the two sets of neurons we find that the one that projects to the SIP also outputs to the local neurons within the LH. The design of simultaneous output at the LH and the SIP, an output of the MB, allows for coordination between innate and learned responses.

scholarly journals Quantitative Analysis of 1300-nm Three-photon Calcium Imaging in the Mouse Brain

2019 ◽  
Author(s):  
Tianyu Wang ◽  
Chunyan Wu ◽  
Dimitre G. Ouzounov ◽  
Wenchao Gu ◽  
Fei Xia ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Large Scale ◽  
Brain Regions ◽  
Excitation Power ◽  
Excitation Pulse ◽  
Two Photon ◽  
Tissue Heating ◽  
Photon Count ◽  
Photon Excitation ◽  
Deep Brain

Abstract1300-nm three-photon calcium imaging has emerged as a useful technique to allow calcium imaging in deep brain regions. Application to large-scale neural activity imaging entails a careful balance between recording fidelity and tissue heating. We calculated and experimentally verified the excitation pulse energy to achieve the minimum photon count required for the detection of calcium transients in GCaMP6s-expressing neurons for 920-nm two-photon and 1320-nm three-photon excitation, respectively. Brain tissue heating by continuous three-photon imaging was simulated with Monte Carlo method and experimentally validated with immunohistochemistry. We observed increased immunoreactivity with 150 mW excitation power at 1.0- and 1.2-mm imaging depths. Based on the data, we explained how three-photon excitation achieves better calcium imaging fidelity than two-photon excitation in the deep brain and quantified the imaging depth where three-photon microscopy should be applied. Our analysis presents a translatable model for the optimization of three-photon calcium imaging based on experimentally tractable parameters.

scholarly journals Quantitative analysis of 1300-nm three-photon calcium imaging in the mouse brain

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Tianyu Wang ◽  
Chunyan Wu ◽  
Dimitre G Ouzounov ◽  
Wenchao Gu ◽  
Fei Xia ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Large Scale ◽  
Brain Regions ◽  
Excitation Power ◽  
Signal Attenuation ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Tissue Heating ◽  
Photon Excitation ◽  
Deep Brain

1300 nm three-photon calcium imaging has emerged as a useful technique to allow calcium imaging in deep brain regions. Application to large-scale neural activity imaging entails a careful balance between recording fidelity and perturbation to the sample. We calculated and experimentally verified the excitation pulse energy to achieve the minimum photon count required for the detection of calcium transients in GCaMP6s-expressing neurons for 920 nm two-photon and 1320 nm three-photon excitation. By considering the combined effects of in-focus signal attenuation and out-of-focus background generation, we quantified the cross-over depth beyond which three-photon microscopy outpeforms two-photon microscopy in recording fidelity. Brain tissue heating by continuous three-photon imaging was simulated with Monte Carlo method and experimentally validated with immunohistochemistry. Increased immunoreactivity was observed with 150 mW excitation power at 1 and 1.2 mm imaging depths. Our analysis presents a translatable model for the optimization of three-photon calcium imaging based on experimentally tractable parameters.

scholarly journals Targeted Esterase induced Dye loading supports Calcium Imaging in Eukaryotic Cell-Free Systems

2020 ◽  
Author(s):  
Priyavathi Dhandapani ◽  
Srujan Kumar Dondapati ◽  
Anne Zemella ◽  
Dennis Bräuer ◽  
Doreen Anja Wüstenhagen ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Calcium Imaging ◽  
Eukaryotic Cell ◽  
Translation System ◽  
Acetoxymethyl Ester ◽  
Imaging Tool ◽  
Dye Loading ◽  
Ester Moiety ◽  
A Cell ◽  
Model Channel

ABSTRACTCalcium imaging is an important functional tool for addressing ion channels, transporters and pumps for drug screening in living cells. Depicted eukaryotic cell-free systems utilize microsomes, derived from endoplasmic reticulum to incorporate the synthesized membrane proteins. Absence or inadequate amount of carboxylesterase in the endoplasmic reticulum of eukaryotic cells, which is necessary to cleave the acetoxymethyl ester moiety of the chemical calcium indicators, advocates the hindrance to perform calcium imaging in microsomes. In this work, we try to overcome this drawback and adapt the cell-based calcium imaging principle to a cell-free protein synthesis platform. Carboxylesterase synthesized in a Spodoptera frugiperda Sf21 lysate translation system is established as a viable calcium imaging tool and hTRPV1 is used as a model channel protein to demonstrate the realization of this concept.

scholarly journals Hearing assessment during deep brain stimulation of the central nucleus of the inferior colliculus and dentate cerebellar nucleus in rat

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3892 ◽  
Author(s):  
Jasper V. Smit ◽  
Ali Jahanshahi ◽  
Marcus L.F. Janssen ◽  
Robert J. Stokroos ◽  
Yasin Temel
Keyword(s):  
Deep Brain Stimulation ◽  
Inferior Colliculus ◽  
Brain Stimulation ◽  
Amplitude Ratio ◽  
Cerebellar Nucleus ◽  
Central Nucleus ◽  
High Frequency Stimulation ◽  
Brainstem Response ◽  
Frequency Stimulation ◽  
Deep Brain

BackgroundRecently it has been shown in animal studies that deep brain stimulation (DBS) of auditory structures was able to reduce tinnitus-like behavior. However, the question arises whether hearing might be impaired when interfering in auditory-related network loops with DBS.MethodsThe auditory brainstem response (ABR) was measured in rats during high frequency stimulation (HFS) and low frequency stimulation (LFS) in the central nucleus of the inferior colliculus (CIC,n = 5) or dentate cerebellar nucleus (DCBN,n = 5). Besides hearing thresholds using ABR, relative measures of latency and amplitude can be extracted from the ABR. In this study ABR thresholds, interpeak latencies (I–III, III–V, I–V) and V/I amplitude ratio were measured during off-stimulation state and during LFS and HFS.ResultsIn both the CIC and the CNBN groups, no significant differences were observed for all outcome measures.DiscussionDBS in both the CIC and the CNBN did not have adverse effects on hearing measurements. These findings suggest that DBS does not hamper physiological processing in the auditory circuitry.

Characterizing the contribution of voltage- and calcium-dependent coupling to action potential stability: implications for repolarization alternans

2007 ◽  
Vol 293 (4) ◽  
pp. H2109-H2118 ◽  
Author(s):  
Peter N. Jordan ◽  
David J. Christini
Keyword(s):  
Action Potential ◽  
Calcium Imaging ◽  
Calcium Transient ◽  
Calcium Handling ◽  
Calcium Dependent ◽  
Relative Contribution ◽  
Real Time Measurement ◽  
Transmembrane Voltage ◽  
Voltage Clamping ◽  
Potential Stability

Experiments have provided suggestive but inconclusive insights into the relative contributions of transmembrane voltage and intracellular calcium handling to the development of cardiac electrical instabilities such as repolarization alternans. In this study, we applied a novel combination of techniques (action potential voltage clamping, calcium-transient clamping, and stability analysis) to cardiac cell models to more clearly determine the roles that voltage- and calcium-dependent coupling play in regulating action potential stability and the development of alternans subsequent to the loss of stability. Using these techniques, we are able to demonstrate that voltage- and calcium-dependent coupling exhibit varying degrees of influence on action potential stability across models. Our results indicate that cellular dynamic instabilities such as alternans may be initiated by either voltage- or calcium-dependent mechanisms or by some combination of the two. Based on these modeling results, we propose novel single-cell experiments that incorporate action-potential voltage clamping, calcium imaging, and real-time measurement of action potential stability. These experiments will make it possible to experimentally determine the relative contribution of voltage coupling to the regulation of action potential stability in real cardiac myocytes, thereby providing further insights into the mechanism of alternans.

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