Live-cell imaging of dendritic spines by STED microscopy

Dendritic spines are specialized postsynaptic structures that transduce presynaptic signals, are regulated by neural activity and correlated with learning and memory. Most studies of spine function have focused on the mammalian nervous system. However, spine-like protrusions have been reported in C. elegans (Philbrook et al., 2018), suggesting that the experimental advantages of smaller model organisms could be exploited to study the biology of dendritic spines. Here, we used super-resolution microscopy, electron microscopy, live-cell imaging and genetics to show that C. elegans motor neurons have functional dendritic spines that: (1) are structurally defined by a dynamic actin cytoskeleton; (2) appose presynaptic dense projections; (3) localize ER and ribosomes; (4) display calcium transients triggered by presynaptic activity and propagated by internal Ca++ stores; (5) respond to activity-dependent signals that regulate spine density. These studies provide a solid foundation for a new experimental paradigm that exploits the power of C. elegans genetics and live-cell imaging for fundamental studies of dendritic spine morphogenesis and function.

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Activity-dependent release of tissue plasminogen activator from the dendritic spines of hippocampal neurons revealed by live-cell imaging

Journal of Neurobiology ◽

10.1002/neu.20250 ◽

2006 ◽

Vol 66 (6) ◽

pp. 564-577 ◽

Cited By ~ 80

Author(s):

Janis E. Lochner ◽

Leah S. Honigman ◽

Wilmon F. Grant ◽

Sarah K. Gessford ◽

Alexis B. Hansen ◽

...

Keyword(s):

Plasminogen Activator ◽

Tissue Plasminogen Activator ◽

Dendritic Spines ◽

Hippocampal Neurons ◽

Live Cell Imaging ◽

Cell Imaging ◽

Live Cell ◽

Tissue Plasminogen ◽

Activity Dependent

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Dendritic spines on GABAergic neurons respond to cholinergic signaling in theCaenorhabditis elegansmotor circuit

10.1101/598714 ◽

2019 ◽

Cited By ~ 1

Author(s):

Andrea Cuentas-Condori ◽

Ben Mulcahy ◽

Siwei He ◽

Sierra Palumbos ◽

Mei Zhen ◽

...

Keyword(s):

Actin Cytoskeleton ◽

Motor Neurons ◽

Dendritic Spines ◽

Live Cell Imaging ◽

Cell Imaging ◽

Live Cell ◽

Spine Density ◽

C Elegans ◽

Cholinergic Signaling ◽

Spine Morphogenesis

SUMMARYDendritic spines are specialized postsynaptic structures that detect and integrate presynaptic signals. The shape and number of dendritic spines are regulated by neural activity and correlated with learning and memory. Most studies of spine function have focused on the mammalian nervous system. However, spine-like protrusions have been previously reported in invertebrates, suggesting that the experimental advantages of smaller model organisms could be exploited to study the biology of dendritic spines. Here, we document the presence of dendritic spines inCaenorhabditis elegansmotor neurons. We used super-resolution microscopy, electron microscopy, live-cell imaging and genetic manipulation to show that GABAergic motor neurons display functional dendritic spines. Our analysis revealed salient features of dendritic spines: (1) A key role for the actin cytoskeleton in spine morphogenesis; (2) Postsynaptic receptor complexes at the tips of spines in close proximity to presynaptic active zones; (3) Localized postsynaptic calcium transients evoked by presynaptic activity; (4) The presence of endoplasmic reticulum and ribosomes; (5) The regulation of spine density by presynaptic activity. These studies provide a solid foundation for a new experimental paradigm that exploits the power ofC. elegansgenetics and live-cell imaging for fundamental studies of dendritic spine morphogenesis and function.HIGHLIGHTS-Spines inC. elegansGABAergic motor neurons are enriched in actin cytoskeleton.-Spines are dynamic structures.-Spines display Ca++transients coupled with presynaptic activation.-Spine density is regulated during development and is modulated by actin dynamics and cholinergic signaling.

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Low-Power Two-Color Stimulated Emission Depletion Microscopy for Live Cell Imaging

Biosensors ◽

10.3390/bios11090330 ◽

2021 ◽

Vol 11 (9) ◽

pp. 330

Author(s):

Jia Zhang ◽

Xinwei Gao ◽

Luwei Wang ◽

Yong Guo ◽

Yinru Zhu ◽

...

Keyword(s):

Low Power ◽

Live Cell Imaging ◽

Cell Imaging ◽

Super Resolution ◽

Live Cell ◽

Stimulated Emission ◽

Live Cells ◽

Sted Microscopy ◽

Resolution Imaging ◽

Stimulated Emission Depletion

Stimulated emission depletion (STED) microscopy is a typical laser-scanning super-resolution imaging technology, the emergence of which has opened a new research window for studying the dynamic processes of live biological samples on a nanometer scale. According to the characteristics of STED, a high depletion power is required to obtain a high resolution. However, a high laser power can induce severe phototoxicity and photobleaching, which limits the applications for live cell imaging, especially in two-color STED super-resolution imaging. Therefore, we developed a low-power two-color STED super-resolution microscope with a single supercontinuum white-light laser. Using this system, we achieved low-power two-color super-resolution imaging based on digital enhancement technology. Lateral resolutions of 109 and 78 nm were obtained for mitochondria and microtubules in live cells, respectively, with 0.8 mW depletion power. These results highlight the great potential of the novel digitally enhanced two-color STED microscopy for long-term dynamic imaging of live cells.

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