Two-Photon Sodium Imaging in Dendritic Spines

2012 ◽  
Vol 2012 (11) ◽  
pp. pdb.prot072074-pdb.prot072074 ◽  
Author(s):  
C. R. Rose
Author(s):  
Ivar S. Stein ◽  
Travis C. Hill ◽  
Won Chan Oh ◽  
Laxmi K. Parajuli ◽  
Karen Zito

2019 ◽  
Author(s):  
Felix C. Nebeling ◽  
Stefanie Poll ◽  
Lena C. Schmid ◽  
Manuel Mittag ◽  
Julia Steffen ◽  
...  

AbstractMicroglia, the resident immune cells of the brain, play a complex role in health and disease. They actively survey the brain parenchyma by physically interacting with other cells and structurally shaping the brain. Yet, the mechanisms underlying microglia motility and their significance for synapse stability, especially during adulthood, remain widely unresolved. Here we investigated the impact of neuronal activity on microglia motility and its implication for synapse formation and survival. We used repetitive two-photon in vivo imaging in the hippocampus of awake mice to simultaneously study microglia motility and their interaction with synapses. We found that microglia process motility depended on neuronal activity. Simultaneously, more dendritic spines emerged in awake compared to anesthetized mice. Interestingly, microglia contact rates with individual dendritic spines were associated with their stability. These results suggest that microglia are not only sensing neuronal activity, but participate in synaptic rewiring of the hippocampus during adulthood, which has profound relevance for learning and memory processes.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jun Noguchi ◽  
Akira Nagaoka ◽  
Tatsuya Hayama ◽  
Hasan Ucar ◽  
Sho Yagishita ◽  
...  

Abstract Most excitatory synapses in the brain form on dendritic spines. Two-photon uncaging of glutamate is widely utilized to characterize the structural plasticity of dendritic spines in brain slice preparations in vitro. In the present study, glutamate uncaging was used to investigate spine plasticity, for the first time, in vivo. A caged glutamate compound was applied to the surface of the mouse visual cortex in vivo, revealing the successful induction of spine enlargement by repetitive two-photon uncaging in a magnesium free solution. Notably, this induction occurred in a smaller fraction of spines in the neocortex in vivo (22%) than in hippocampal slices (95%). Once induced, the time course and mean long-term enlargement amplitudes were similar to those found in hippocampal slices. However, low-frequency (1–2 Hz) glutamate uncaging in the presence of magnesium caused spine shrinkage in a similar fraction (35%) of spines as in hippocampal slices, though spread to neighboring spines occurred less frequently than it did in hippocampal slices. Thus, the structural plasticity may occur similarly in the neocortex in vivo as in hippocampal slices, although it happened less frequently in our experimental conditions.


PLoS ONE ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. e0128241 ◽  
Author(s):  
Jian-Hua Chen ◽  
Yves Kellner ◽  
Marta Zagrebelsky ◽  
Matthias Grunwald ◽  
Martin Korte ◽  
...  

2013 ◽  
Vol 4 (8) ◽  
pp. 1163-1167 ◽  
Author(s):  
Roberto Araya ◽  
Victoria Andino-Pavlovsky ◽  
Rafael Yuste ◽  
Roberto Etchenique
Keyword(s):  

eNeuro ◽  
2015 ◽  
Vol 2 (4) ◽  
pp. ENEURO.0019-15.2015 ◽  
Author(s):  
Osamu Sadakane ◽  
Akiya Watakabe ◽  
Masanari Ohtsuka ◽  
Masafumi Takaji ◽  
Tetsuya Sasaki ◽  
...  

2018 ◽  
Vol 29 (7) ◽  
pp. 2771-2781 ◽  
Author(s):  
Taekyung Kwon ◽  
Angel Merchán-Pérez ◽  
Emiliano M Rial Verde ◽  
José-Rodrigo Rodríguez ◽  
Javier DeFelipe ◽  
...  

Abstract The location of GABAergic synapses on dendrites is likely key for neuronal integration. In particular, inhibitory inputs on dendritic spines could serve to selectively veto or modulate individual excitatory inputs, greatly expanding the computational power of individual neurons. To investigate this, we have undertaken a combined functional, molecular, and ultrastructural mapping of the location of GABAergic inputs onto dendrites of pyramidal neurons from upper layers of juvenile mouse somatosensory cortex. Using two-photon uncaging of GABA, intracellular labeling with gerphyrin intrabodies, and focused ion beam milling with scanning electron microscopy, we find that most (96–98%) spines lack GABAergic synapses, although they still display GABAergic responses, potentially due to extrasynaptic GABA receptors. We conclude that GABAergic inputs, in practice, contact dendritic shafts and likely control clusters of excitatory inputs, defining functional zones on dendrites.


2011 ◽  
Vol 71 ◽  
pp. e206
Author(s):  
Jun Noguchi ◽  
Akira Nagaoka ◽  
Satoshi Watanabe ◽  
Graham C.R. Ellis-Davies ◽  
Kazuo Kitamura ◽  
...  

2014 ◽  
Vol 111 (10) ◽  
pp. 1960-1972 ◽  
Author(s):  
Hannah J. Seong ◽  
Rudy Behnia ◽  
Adam G. Carter

Glutamatergic inputs onto cortical pyramidal neurons are received and initially processed at dendritic spines. AMPA and NMDA receptors generate both synaptic potentials and calcium (Ca) signals in the spine head. These responses can in turn activate a variety of Ca, sodium (Na), and potassium (K) channels at spines. In principle, the roles of these receptors and channels can be strongly regulated by the subthreshold membrane potential. However, the impact of different receptors and channels has usually been studied at the level of dendrites. Much less is known about their influence at spines, where synaptic transmission and plasticity primarily occur. Here we examine single-spine responses in the basal dendrites of layer 5 pyramidal neurons in the mouse prefrontal cortex. Using two-photon microscopy and two-photon uncaging, we first show that synaptic potentials and Ca signals differ at resting and near-threshold potentials. We then determine how subthreshold depolarizations alter the contributions of AMPA and NMDA receptors to synaptic responses. We show that voltage-sensitive Ca channels enhance synaptic Ca signals but fail to engage small-conductance Ca-activated K (SK) channels, which require greater numbers of inputs. Finally, we establish how the subthreshold membrane potential controls the ability of voltage-sensitive Na channels and K channels to influence synaptic responses. Our findings reveal how subthreshold depolarizations promote electrical and biochemical signaling at dendritic spines by regulating the contributions of multiple glutamate receptors and ion channels.


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