Name: successful in vivo calcium imaging with a head-mount miniaturized microscope in the amygdala of freely behaving mouse
Uploaded: 2020-08-26T14:00:00.000+00:00
Duration: 9 min 39 s
Description: Watch this Scientific Journal Video about Successful In vivo Calcium Imaging with a Head-Mount Miniaturized Microscope in the Amygdala of Freely Behaving Mouse at JoVE.com

Este trabalho foi apoiado por subsídios da Samsung Science and Technology Foundation (Project Number SSTF-BA1801-10).

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Técnicas de cirurgia habilidosas são essenciais para alcançar imagens de cálcio óptica in vivo bem sucedidas com microscopia em miniatura de montagem de cabeça em regiões cerebrais mais profundas, como a amígdala como descrevemos aqui. Portanto, embora este protocolo forneça uma diretriz para processos cirúrgicos otimizados de fixação de placas base e implantação de lentes GRIN, processos adicionais de otimização podem ser necessários para etapas críticas. Como mencionado na seção de protocolo, amígd...

O cálcio é um segundo mensageiro onipresente, desempenhando um papel crucial em quase todas as funções celulares8. Nos neurônios, o potencial de ação de disparo e a entrada sináptica causam rápida mudança de livre intracelular [Ca2+]9,10. Portanto, o rastreamento de transintes de cálcio oferece uma oportunidade de monitorar a atividade neuronal. GeCIs são ferramentas poderosas que permitem o monitoramento [Ca2+] em populações celulares definidas e compartimentos intracelulares11,12. Entre muitos tipos diferentes de indicador de cálcio à base de proteína, o GCaMP, uma sonda Ca2+baseada em uma única molécula de GFP13,é a GECI mais otimizada e, portanto, amplamente utilizada. Através de várias rodadas de engenharia, uma série de variantes de GCaMP foi desenvolvida12,14,15,16. Utilizamos um dos GCaMPs recentemente desenvolvidos, GCaMP7b, neste protocolo16. Os sensores GCaMP contribuíram muito para o estudo das funções do circuito neural em uma série de organismos modelo, como imagens de transientes Ca2+ durante o desenvolvimento17, imagem in vivo em uma camada cortical específica18,medição da dinâmica do circuito no aprendizado de tarefas motoras19 e imagem da atividade do conjunto celular relacionada com memória de medo associativo no hipocampo e amígdala20,21.
A imagem óptica de GECIs tem várias vantagens22. A codificação genética permite que os GECIs sejam expressos por um longo período de tempo em um subconjunto específico de células definidas por perfil genético ou padrões específicos de conectividade anatômica. A imagem óptica permite o monitoramento simultâneo in vivo de centenas a milhares de neurônios em animais vivos. Alguns sistemas ópticos de imagem foram desenvolvidos para imagens in vivo e análise de GECIs dentro do cérebro de camundongos que se comportam livremente com microscópios de fluorescência miniaturizada de montagem da cabeça21,23,24,25. Apesar da técnica de imagem óptica in vivo baseada em GECIs, lente GRIN e um microscópio em miniatura de montagem de cabeça ser uma ferramenta poderosa para estudar a ligação entre a atividade do circuito neural e o comportamento, aplicar essa tecnologia à amígdala tem sido difícil devido a vários problemas técnicos relacionados com o direcionamento da lente GRIN para células expressando GECIs na amígdala sem causar artefatos de movimento que reduzem severamente a qualidade da aquisição de imagens e encontrar células expressas gecIs. Este protocolo visa fornecer uma diretriz útil para procedimentos cirúrgicos de fixação de placa base e implantação de lentes GRIN que são etapas críticas para o sucesso da imagem óptica de cálcio in vivo na amígdala. Embora este protocolo tenha como alvo a amígdala, a maioria dos procedimentos descritos aqui são comumente aplicáveis a outras regiões cerebrais mais profundas. Embora este protocolo seja baseado em um sistema específico (por exemplo, Inscopix), o mesmo propósito pode ser facilmente alcançado com outros sistemas alternativos.

<table><tbody><tr><td>26G needle</td><td>BD</td><td>302002</td><td>Surgery</td></tr><tr><td>AAV1-Syn-GCaMP7b-WPRE</td><td>Addgene</td><td>104493-AAV1</td><td>Surgery</td></tr><tr><td>AAV2/1-CaMKii&amp;alpha;-GFP</td><td>custom made</td><td></td><td>Surgery</td></tr><tr><td>Acrylic-Dental cement (Ortho-jet Acrylic Pink)</td><td>Lang</td><td>1334-pink</td><td>Surgery &amp;amp; Baseplate Attachment</td></tr><tr><td>Air flow manipulator</td><td>Neurotar</td><td>NTR000253-04</td><td>Baseplate Attachment</td></tr><tr><td>Amoxicillin</td><td>SIGMA</td><td>A8523-5G</td><td>Surgery</td></tr><tr><td>Baseplate</td><td>INSCOPIX</td><td>1050-002192</td><td>Baseplate Attachment</td></tr><tr><td>Baseplate cover</td><td>INSCOPIX</td><td>1050-002193</td><td>Baseplate Attachment</td></tr><tr><td>Behavioral apparatus (chamber)</td><td>Coulbourn Instrument</td><td>Testcage</td><td>Behavior test</td></tr><tr><td>Behavioral apparatus (software)</td><td>Coulbourn Instrument</td><td>Freeze Frame</td><td>Behavior test</td></tr><tr><td>Carbon cage</td><td>Neurotar</td><td>180mm x 70mm</td><td>Baseplate Attachment</td></tr><tr><td>Carprofen</td><td>SIGMA</td><td>PHR1452-1G</td><td>Surgery</td></tr><tr><td>Data processing software</td><td>INSCOPIX</td><td>INSCOPIX Data Processing Software</td><td>Baseplate Attachment &amp;amp; Behavior test</td></tr><tr><td>Dexamethasone</td><td>SIGMA</td><td>D1756-500MG</td><td>Surgery</td></tr><tr><td>Drill</td><td>Seyang</td><td>marathon-4</td><td>Surgery</td></tr><tr><td>Drill bur</td><td>ELA</td><td>US1/2, Shank104</td><td>Surgery</td></tr><tr><td>Glass needle</td><td>WPI</td><td>PG10165-4</td><td>Surgery</td></tr><tr><td>GRIN lens (INSCOPIX Proview Lens Probe)</td><td>INSCOPIX</td><td>1050-002208</td><td>Surgery</td></tr><tr><td>Hamilton Syringe</td><td>Hamilton</td><td>84875</td><td>Surgery</td></tr><tr><td>Head plate</td><td>Neurotar</td><td>Model 5</td><td>Surgery</td></tr><tr><td>Hex-key</td><td>INSCOPIX</td><td>1050-004195</td><td>Baseplate Attachment</td></tr><tr><td>Laptop computer</td><td>Samsung</td><td>NT950XBV</td><td>Surgery &amp;amp; Baseplate Attachment</td></tr><tr><td>Lens holder, Stereotaxic rod (INSCOPIX proview implant kit)</td><td>INSCOPIX</td><td>1050-004223</td><td>Surgery</td></tr><tr><td>Microscope gripper</td><td>INSCOPIX</td><td>1050-002199</td><td>Baseplate Attachment</td></tr><tr><td>Microscope, DAQ software, hardware</td><td>INSCOPIX</td><td>nVista 3.0</td><td>Baseplate Attachment &amp;amp; Behavior test</td></tr><tr><td>Mobile homecage</td><td>Neurotar</td><td>MHC V5</td><td>Baseplate Attachment</td></tr><tr><td>Moterized arm</td><td>Neurostar</td><td>Customized</td><td>Surgery</td></tr><tr><td>Moterized arm software</td><td>Neurostar</td><td>Customized</td><td>Surgery</td></tr><tr><td>NI board</td><td>National instrument</td><td></td><td>Behavior test</td></tr><tr><td>Removable epoxy bond</td><td>WPI</td><td>Kwik-Cast</td><td>Surgery</td></tr><tr><td>Resin cement (Super-bond)</td><td>Sun medical</td><td>Super bond C&amp;amp;B</td><td>Surgery</td></tr><tr><td>Skull screw</td><td>Stoelting</td><td>51457</td><td>Surgery</td></tr><tr><td>Stereotaxic electrode holder</td><td>ASI</td><td>EH-600</td><td>Surgery</td></tr><tr><td>Stereotaxic frame</td><td>Stoelting</td><td>51600</td><td>Surgery</td></tr><tr><td>Stereotaxic manipulator</td><td>Stoelting</td><td>51600</td><td>Baseplate Attachment</td></tr></tbody></table>

successful in vivo calcium imaging with a head-mount miniaturized microscope in the amygdala of freely behaving mouse

O monitoramento in vivo em tempo real das atividades neuronais em animais em movimento livre é uma das principais abordagens para ligar a atividade neuronal ao comportamento. Para isso, uma técnica de imagem in vivo que detecta transitórios de cálcio em neurônios usando indicadores de cálcio geneticamente codificados (GECIs), um microscópio de fluorescência miniaturizada e uma lente de índice de refração gradiente (GRIN) foi desenvolvida e aplicada com sucesso em muitas estruturas cerebrais1,2,3,4,5,6. Esta técnica de imagem é particularmente poderosa porque permite imagens simultâneas crônicas de populações celulares geneticamente definidas por um período de longo prazo até várias semanas. Embora útil, essa técnica de imagem não tem sido facilmente aplicada às estruturas cerebrais que se localizam profundamente dentro do cérebro, como a amígdala, uma estrutura cerebral essencial para o processamento emocional e a memória do medo associativo7. Existem vários fatores que dificultam a aplicação da técnica de imagem na amígdala. Por exemplo, artefatos de movimento geralmente ocorrem com mais frequência durante a imagem realizada nas regiões cerebrais mais profundas porque um microscópio de montagem de cabeça implantado nas profundezas do cérebro é relativamente instável. Outro problema é que o ventrículo lateral está posicionado perto da lente GRIN implantada e seu movimento durante a respiração pode causar artefatos de movimento altamente irregulares que não podem ser facilmente corrigidos, o que dificulta a formação de uma visão de imagem estável. Além disso, como as células da amígdala são geralmente silenciosas em um estado de repouso ou anestesiado, é difícil encontrar e concentrar as células-alvo expressando GECI na amígdala durante o procedimento de base para imagens posteriores. Este protocolo fornece uma diretriz útil para como direcionar eficientemente as células expressando GECI na amígdala com microscópio miniaturizado de montagem de cabeça para imagens de cálcio in vivo bem sucedidas em uma região cerebral tão profunda. Nota-se que este protocolo é baseado em um sistema específico (por exemplo, Inscopix), mas não restrito a ele.

Validação da implantação das lentes GRIN Antes de anexar cronicamente a placa base ao cérebro por cimentação, a implantação da lente GRIN precisa ser validada. Em animais com implantação bem sucedida de lentes, tanto células expressas GCaMP quanto vasos sanguíneos foram claramente observados dentro de uma faixa de plano focal determinada pela distância entre lente objetiva de microscópio e lente GRIN implantada(Figura 2A e B</stron...

Watch this Scientific Journal Video about Successful In vivo Calcium Imaging with a Head-Mount Miniaturized Microscope in the Amygdala of Freely Behaving Mouse at JoVE.com

Successful In vivo Calcium Imaging with a Head-Mount Miniaturized Microscope in the Amygdala of Freely Behaving Mouse

A imagem microendoscópica de cálcio in vivo é uma ferramenta inestimável que permite o monitoramento em tempo real das atividades neuronais em animais de comportamento livre. No entanto, aplicar essa técnica à amígdala tem sido difícil. Este protocolo visa fornecer uma diretriz útil para atingir com sucesso células de amígdala com um microscópio miniaturizado em camundongos.

Imagem de cálcio in vivo bem sucedida com um microscópio miniaturizado de head-mount na Amígdala do Rato Livremente Comportado

In vivo real-time monitoring of neuronal activities in freely moving animals is one of key approaches to link neuronal activity to behavior. For this ...

successful-vivo-calcium-imaging-with-head-mount-miniaturized

Research

JoVE Journal

Neuroscience

12.1K visualizações.  Korea Advanced Institute of Science and Technology (KAIST). A imagem microendoscópica de cálcio in vivo é uma ferramenta inestimável que permite o monitoramento em tempo real das atividades neuronais em animais de comportamento livre. No entanto, aplicar essa técnica à amígdala tem sido difícil. Este protocolo visa fornecer uma diretriz útil para atingir com sucesso células de amígdala com um microscópio miniaturizado em camundongos.

Vídeo: Successful In vivo Calcium Imaging with a Head-Mount Miniaturized Microscope in the Amygdala of Freely Behaving Mouse

Two-photon Calcium Imaging in Mice Navigating a Virtual Reality Environment

In recent years, two-photon imaging has become an invaluable tool in neuroscience, as it allows for chronic measurement of the activity of genetically identified cells during behavior1-6. Here we describe methods to perform two-photon imaging in mouse cortex while the animal navigates a virtual reality environment. We focus on the aspects of the experimental procedures that are key to imaging in a behaving animal in a brightly lit virtual environment. The key problems that arise in this experimental setup that we here address are: minimizing brain motion related artifacts, minimizing light leak from the virtual reality projection system, and minimizing laser induced tissue damage. We also provide sample software to control the virtual reality environment and to do pupil tracking. With these procedures and resources it should be possible to convert a conventional two-photon microscope for use in behaving mice.

Here we describe the experimental procedures involved in two-photon imaging of mouse cortex during behavior in a virtual reality environment.

Dois fótons de imagem de cálcio em camundongos Navegando um ambiente da realidade virtual

In recent years, two-photon imaging has become an invaluable tool in neuroscience, as it allows for chronic measurement of the activity of genetically ...

Comportamento

In vivo Calcium Imaging in Mouse Inferior Olive

Inferior olive (IO), a nucleus in the ventral medulla, is the only source of climbing fibers that form one of the two input pathways entering the cerebellum. IO has long been proposed to be crucial for motor control and its activity is currently considered to be at the center of many hypotheses of both motor and cognitive functions of the cerebellum. While its physiology and function have been relatively well studied on single-cell level in vitro, presently there are no reports on the organization of the IO network activity in living animals. This is largely due to the extremely challenging anatomical location of the IO, making it difficult to subject to conventional fluorescent imaging methods, where an optic path must be created through the entire brain located dorsally to the region of interest.
Here we describe an alternative method for obtaining state-of-the-art -level calcium imaging data from the IO network. The method takes advantage of the extreme ventral location of the IO and involves a surgical procedure for inserting a gradient-refractive index (GRIN) lens through the neck viscera to come into contact with the ventral surface of the calcium sensor GCaMP6s-expressing IO in anesthetized mice. A representative calcium imaging recording is shown to demonstrate the feasibility to record IO neuron activity after the surgery. While this is a non-survival surgery and the recordings must be conducted under anesthesia, it avoids damage to life-critical brainstem nuclei and allows conducting large variety of experiments investigating spatiotemporal activity patterns and input integration in the IO. This procedure with modifications could be used for recordings in other, adjacent regions of the ventral brainstem.

In vivo Calcium Imaging in Mouse Inferior Olive

We present a protocol to expose the brainstem of adult mouse from the ventral side. By using a gradient-refractive index lens with a miniature microscope, calcium imaging can be used to examine the activity of inferior olive neural somata in vivo.

In vivo Imagem de cálcio em rato de azeitona inferior

Inferior olive (IO), a nucleus in the ventral medulla, is the only source of climbing fibers that form one of the two input pathways entering the ...

Neurociência

Craniotomy Procedure for Visualizing Neuronal Activities in Hippocampus of Behaving Mice

Imaging neuronal activities at single-cell resolution in awake behaving animals is a very powerful approach for the investigation of neural circuit functions in systems neuroscience. However, high absorbance and scattering of light in mammalian tissue limit intravital imaging mostly to superficial brain regions, leaving deep-brain areas, such as the hippocampus, out of reach for optical microscopy. In this video, we show the preparation and implantation of the custom-made imaging window to enable chronic in vivo imaging of the dorsal hippocampal CA1 region in head-fixed behaving mice. The custom-made window is supplemented with an infusion cannula that allows targeted delivery of viral vectors and drugs to the imaging area. By combining this preparation with wide-field imaging, we performed a long-term recording of neuronal activity using a fluorescent calcium indicator from large subsets of neurons in behaving mice over several weeks. We also demonstrated the applicability of this preparation for voltage imaging with single-spike resolution. High-performance genetically encoded indicators of neuronal activity and scientific CMOS cameras allowed the recurrent visualization of subcellular morphological details of single neurons at high temporal resolution. We also discuss the advantages and potential limitations of the described method and its compatibility with other imaging techniques.

This article demonstrates the preparation of a custom-made imaging window supplemented with infusion cannula and its implantation onto the CA1 region of the hippocampus in mice.

Procedimento de craniotomia para visualizar atividades neuronais no hipocampo de ratos comportadores

Imaging neuronal activities at single-cell resolution in awake behaving animals is a very powerful approach for the investigation of neural circuit ...

Implantation of a Cranial Window for Repeated In Vivo Imaging in Awake Mice

To fully understand the cellular physiology of neurons and glia in behaving animals, it is necessary to visualize their morphology and record their activity in vivo in behaving mice. This paper describes a method for the implantation of a chronic cranial window to allow for the longitudinal imaging of brain cells in awake, head-restrained mice. In combination with genetic strategies and viral injections, it is possible to label specific cells and regions of interest with structural or physiological markers. This protocol demonstrates how to combine viral injections to label neurons in the vicinity of GCaMP6-expressing astrocytes in the cortex for simultaneous imaging of both cells through a cranial window. Multiphoton imaging of the same cells can be performed for days, weeks, or months in awake, behaving animals. This approach provides researchers with a method for viewing cellular dynamics in real time and can be applied to answer a number of questions in neuroscience.

Implantation of a Cranial Window for Repeated In Vivo Imaging in Awake Mice

Presented here is a protocol for the implantation of a chronic cranial window for the longitudinal imaging of brain cells in awake, head-restrained mice.

Implantação de uma janela craniana para imagem repetida em vivo em ratos acordados

To fully understand the cellular physiology of neurons and glia in behaving animals, it is necessary to visualize their morphology and record their ...

Stereotaxic Viral Injection and Gradient-Index Lens Implantation for Deep Brain In Vivo Calcium Imaging

A miniature fluorescence microscope (miniscope) is a potent tool for in vivo calcium imaging from freely behaving animals. It offers several advantages over conventional multi-photon calcium imaging systems: (1) compact; (2) light-weighted; (3) affordable; and (4) allows recording from freely behaving animals. This protocol describes brain surgeries for deep brain in vivo calcium imaging using a custom-developed miniscope recording system. The preparation procedure consists of three steps, including (1) stereotaxically injecting the virus at the desired brain region of a mouse brain to label a specific subgroup of neurons with genetically encoded calcium sensor; (2) implantation of gradient-index (GRIN) lens that can relay calcium image from deep brain region to the miniscope system; and (3) affixing the miniscope holder over the mouse skull where miniscope can be attached later. To perform in vivo calcium imaging, the miniscope is fastened onto the holder, and neuronal calcium images are collected along with simultaneous behavior recordings. The present surgery protocol is compatible with any commercial or custom-built single-photon and two-photon imaging systems for deep brain in vivo calcium imaging.

Stereotaxic Viral Injection and Gradient-Index Lens Implantation for Deep Brain In Vivo Calcium Imaging

Miniscope in vivo calcium imaging is a powerful technique to study neuronal dynamics and microcircuits in freely behaving mice. This protocol describes performing brain surgeries to achieve good in vivo calcium imaging using a miniscope.

Injeção viral esteretaxica e implantação de lente de índice de gradiente para imagem de cálcio no cérebro profundo em vivo

A miniature fluorescence microscope (miniscope) is a potent tool for in vivo calcium imaging from freely behaving animals. It offers several advantages ...

Simultaneous Imaging of Microglial Dynamics and Neuronal Activity in Awake Mice

Since brain functions are under the continuous influence of the signals derived from peripheral tissues, it is critical to elucidate how glial cells in the brain sense various biological conditions in the periphery and transmit the signals to neurons. Microglia, immune cells in the brain, are involved in synaptic development and plasticity. Therefore, the contribution of microglia to neural circuit construction in response to the internal state of the body should be tested critically by intravital imaging of the relationship between microglial dynamics and neuronal activity.
Here, we describe a technique for the simultaneous imaging of microglial dynamics and neuronal activity in awake mice. Adeno-associated virus encoding R-CaMP, a gene-encoded calcium indicator of red fluorescence protein, was injected into layer 2/3 of the primary visual cortex in CX3CR1-EGFP transgenic mice expressing EGFP in microglia. After viral injection, a cranial window was installed onto the brain surface of the injected region. In vivo two-photon imaging in awake mice 4 weeks after the surgery demonstrated that neural activity and microglial dynamics could be recorded simultaneously at the sub-second temporal resolution. This technique can uncover the coordination between microglial dynamics and neuronal activity, with the former responding to peripheral immunological states and the latter encoding the internal brain states.

Here, we describe a protocol combining adeno-associated virus injection with cranial window implantation for simultaneous imaging of microglial dynamics and neuronal activity in awake mice.

Imagem Simultânea da Dinâmica Microglial e Atividade Neuronal em Camundongos Acordados

Since brain functions are under the continuous influence of the signals derived from peripheral tissues, it is critical to elucidate how glial cells in ...

In Vivo Wide-Field and Two-Photon Calcium Imaging from a Mouse Using a Large Cranial Window

Wide-field calcium imaging from the mouse&#39;s neocortex allows one to observe cortex-wide neural activity related to various brain functions. On the other hand, two-photon imaging can resolve the activity of local neural circuits at the single-cell level. It is critical to make a large cranial window to perform multiple-scale analysis using both imaging techniques in the same mouse. To achieve this, one must remove a large section of the skull and cover the exposed cortical surface with transparent materials. Previously, glass skulls and polymer-based cranial windows have been developed for this purpose, but these materials are not easily fabricated. The present protocol describes a simple method for making a large cranial window consisting of commercially available polyvinylidene chloride (PVDC) wrapping film, a transparent silicone plug, and a cover glass. For imaging the dorsal surface of an entire hemisphere, the window size was approximately 6 x 3 mm2. Severe brain vibrations were not observed regardless of such a large window. Importantly, the condition of the brain surface did not deteriorate for more than one month. Wide-field imaging of a mouse expressing a genetically-encoded calcium indicator (GECI), GCaMP6f, specifically in astrocytes, revealed synchronized responses in a few millimeters. Two-photon imaging of the same mouse showed prominent calcium responses in individual astrocytes over several seconds. Furthermore, a thin layer of an adeno-associated virus was applied to the PVDC film and successfully expressed GECI in cortical neurons over the cranial window. This technique is reliable and cost-effective for making a large cranial window and facilitates the investigation of the neural and glial dynamics and their interactions during behavior at the macroscopic and microscopic levels.

In Vivo Wide-Field and Two-Photon Calcium Imaging from a Mouse Using a Large Cranial Window

The present protocol describes making a large (6 x 3 mm2) cranial window using food wrap, transparent silicone, and cover glass. This cranial window allows in vivo wide-field and two-photon calcium imaging experiments in the same mouse.

In vivo Imagem de cálcio de campo amplo e de dois fótons de um rato usando uma grande janela craniana

Wide-field calcium imaging from the mouse&#39;s neocortex allows one to observe cortex-wide neural activity related to various brain functions. On the ...

Subcellular Imaging of Neuronal Calcium Handling In Vivo

Calcium (Ca2+) imaging has been largely used to examine neuronal activity, but it is becoming increasingly clear that subcellular Ca2+ handling is a crucial component of intracellular signaling. The visualization of subcellular Ca2+ dynamics in vivo,&#160;where neurons can be studied in their native, intact circuitry, has proven technically challenging in complex nervous systems. The transparency and relatively simple nervous system of the nematode Caenorhabditis elegans enable the cell-specific expression and in vivo visualization of fluorescent tags and indicators. Among these are fluorescent indicators that have been modified for use in the cytoplasm as well as various subcellular compartments, such as the mitochondria. This protocol enables non-ratiometric Ca2+ imaging in vivo with a subcellular resolution that permits the analysis of Ca2+ dynamics down to the level of individual dendritic spines and mitochondria. Here, two available genetically encoded indicators with different Ca2+ affinities are used to demonstrate the use of this protocol for measuring relative Ca2+ levels within the cytoplasm or mitochondrial matrix in a single pair of excitatory interneurons (AVA). Together with the genetic manipulations and longitudinal observations possible in C. elegans, this imaging protocol may be useful for answering questions regarding how Ca2+ handling regulates neuronal function and plasticity.

Subcellular Imaging of Neuronal Calcium Handling In Vivo

The current methods describe a non-ratiometric approach for high-resolution, sub-compartmental calcium imaging in vivo in Caenorhabditis elegans using readily available genetically encoded calcium indicators.

Imagem Subcelular da Manipulação Neuronal de Cálcio In Vivo

Calcium (Ca2+) imaging has been largely used to examine neuronal activity, but it is becoming increasingly clear that subcellular Ca2+ handling is a ...

Imagem de cálcio de dois fótons e campo amplo no colículo superior

Calcium Imaging in Mouse Superior Colliculus

The superior colliculus (SC), an evolutionarily conserved midbrain structure in all vertebrates, is the most sophisticated visual center before the emergence of the cerebral cortex. It receives direct inputs from ~30 types of retinal ganglion cells (RGCs), with each encoding a specific visual feature. It remains elusive whether the SC simply inherits retinal features or if additional and potentially de novo processing occurs in the SC. To reveal the neural coding of visual information in the SC, we provide here a detailed protocol to optically record visual responses with two complementary methods in awake mice. One method uses two-photon microscopy to image calcium activity at single-cell resolution without ablating the overlaying cortex, while the other uses wide-field microscopy to image the whole SC of a mutant mouse whose cortex is largely undeveloped. This protocol details these two methods, including animal preparation, viral injection, headplate implantation, plug implantation, data acquisition, and data analysis. The representative results show that the two-photon calcium imaging reveals visually evoked neuronal responses at single-cell resolution, and the wide-field calcium imaging reveals&#160;neural activity across the entire SC. By combining these two methods, one can reveal the neural coding in the SC at different scales, and such combination can also be applied to other brain regions.

Autor em destaque: Revelando a codificação neural e os mecanismos de processamento visual no colículo superior 

This protocol details the procedure for imaging calcium responses in the superior colliculus (SC) of awake mice, including imaging single-neuron activity with two-photon microscopy while leaving the cortex intact in wild-type mice, and imaging the entire SC with wide-field microscopy in partial-cortex mutant mice.

Imagem de cálcio no colículo superior de camundongos

The superior colliculus (SC), an evolutionarily conserved midbrain structure in all vertebrates, is the most sophisticated visual center before the ...

Imagem de cálcio in vivo bem sucedida com um microscópio miniaturizado de head-mount na Amígdala do Rato Livremente Comportado

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In vivo Imagem de cálcio em rato de azeitona inferior

Procedimento de craniotomia para visualizar atividades neuronais no hipocampo de ratos comportadores

Implantação de uma janela craniana para imagem repetida em vivo em ratos acordados

Injeção viral esteretaxica e implantação de lente de índice de gradiente para imagem de cálcio no cérebro profundo em vivo

Imagem Simultânea da Dinâmica Microglial e Atividade Neuronal em Camundongos Acordados

In vivo Imagem de cálcio de campo amplo e de dois fótons de um rato usando uma grande janela craniana

Imagem Subcelular da Manipulação Neuronal de Cálcio In Vivo

Imagem de cálcio no colículo superior de camundongos

Imagem de cálcio no colículo superior de camundongos