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

This work was supported by grants from Samsung Science and Technology Foundation (Project Number SSTF-BA1801-10).

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The author has nothing to disclose

Skillful surgery techniques are essential for achieving successful in vivo optical calcium imaging with head-mount miniature microscopy in deeper brain regions such as the amygdala as we described here. Therefore, although this protocol provides a guideline for optimized surgical processes of baseplate attachment and GRIN lens implantation, additional optimization processes might be necessary for critical steps. As mentioned in the protocol section, amygdala coordinates in surgery, airflow speed in baseplate attachment s...

Calcium is a ubiquitous second messenger, playing a crucial role in almost every cellular functions8. In neurons, action potential firing and synaptic input cause rapid change of intracellular free [Ca2+]9,10. Therefore, tracking calcium transients provides an opportunity to monitor neuronal activity. GECIs are powerful tools that allow for monitoring [Ca2+] in defined cell populations and intra-cellular compartments11,12. Among many different types of protein based calcium indicator, GCaMP, a Ca2+ probe based on a single GFP molecule13, is the most optimized and thus widely used GECI. Through multiple rounds of engineering, a number of variants of GCaMP has been developed12,14,15,16. We use one of the recently developed GCaMPs, GCaMP7b, in this protocol16. GCaMP sensors have greatly contributed to the study of neural circuit functions in a number of model organisms such as imaging of Ca2+ transients during development17, in vivo imaging in a specific cortical layer18, measurement of circuit dynamics in motor task learning19 and imaging of cell ensemble activity related with associative fear memory in the hippocampus and amygdala20,21.
Optical imaging of GECIs has several advantages22. Genetic encoding enables GECIs to be stably expressed for a long-term period of time in a specific subset of cells that are defined by genetic profile or specific patterns of anatomical connectivity. Optical imaging enables in vivo chronic simultaneous monitoring of hundreds to thousands of neurons in live animals. A few optical imaging systems have been developed for in vivo imaging and analysis of GECIs within the brain of freely behaving mice with head-mount miniaturized fluorescence microscopes21,23,24,25. Despite the in vivo optical imaging technique based on GECIs, GRIN lens, and a head-mount miniature microscope being a powerful tool to study the link between neural circuit activity and behavior, applying this technology to the amygdala has been difficult due to several technical issues related with targeting the GRIN lens to cells expressing GECIs in the amygdala without causing motion artifacts that severely reduce the quality of image acquisition and finding cells expressing GECIs. This protocol aims to provide a helpful guideline for surgical procedures of baseplate attachment and GRIN lens implantation that are critical steps for successful in vivo optical calcium imaging in the amygdala. Although this protocol targets the amygdala, most procedures described here are commonly applicable to other deeper brain regions. Although this protocol is based on a particular system (e.g., Inscopix), the same purpose may be easily achieved with other alternative systems.

<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

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 purpose, an in vivo imaging technique that detects calcium transients in neurons using genetically encoded calcium indicators (GECIs), a miniaturized fluorescence microscope, and a gradient refractive index (GRIN) lens has been developed and successfully applied to many brain structures1,2,3,4,5,6. This imaging technique is particularly powerful because it enables chronic simultaneous imaging of genetically defined cell populations for a long-term period up to several weeks. Although useful, this imaging technique has not been easily applied to brain structures that locate deep within the brain such as amygdala, an essential brain structure for emotional processing and associative fear memory7. There are several factors that make it difficult to apply the imaging technique to the amygdala. For instance, motion artifacts usually occur more frequently during the imaging conducted in the deeper brain regions because a head-mount microscope implanted deep in the brain is relatively unstable. Another problem is that the lateral ventricle is positioned close to the implanted GRIN lens and its movement during respiration may cause highly irregular motion artifacts that cannot be easily corrected, which makes it difficult to form a stable imaging view. Furthermore, because cells in the amygdala are usually quiet at a resting or anesthetized state, it is hard to find and focus the target cells expressing GECI in the amygdala during baseplating procedure for later imaging. This protocol provides a helpful guideline for how to efficiently target cells expressing GECI in the amygdala with head-mount miniaturized microscope for successful in vivo calcium imaging in such a deeper brain region. It is noted that this protocol is based on a particular system (e.g., Inscopix) but not restricted to it.

Validation of GRIN lens implantation 
Before chronically attaching the baseplate to the brain by cementing, the GRIN lens implantation needs to be validated. In animals with successful lens implantation, both GCaMP expressing cells and blood vessels were clearly observed within a focal plane range determined by the distance between objective lens of microscope and implanted GRIN lens (Figure 2A and B). In contrast, in animals with off-t...

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

In vivo microendoscopic calcium imaging is an invaluable tool that enables real-time monitoring of neuronal activities in freely behaving animals. However, applying this technique to the amygdala has been difficult. This protocol aims to provide a useful guideline for successfully targeting amygdala cells with a miniaturized microscope in mice.

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

Universidad de Cartagena UDEC

Research

JoVE Journal

Neuroscience

12.1K Views.  Korea Advanced Institute of Science and Technology (KAIST). In vivo microendoscopic calcium imaging is an invaluable tool that enables real-time monitoring of neuronal activities in freely behaving animals. However, applying this technique to the amygdala has been difficult. This protocol aims to provide a useful guideline for successfully targeting amygdala cells with a miniaturized microscope in mice.

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

In Vivo 2-Photon Calcium Imaging in Layer 2/3 of Mice

To understand network dynamics of microcircuits in the neocortex, it is essential to simultaneously record the activity of a large number of neurons . In-vivo two-photon calcium imaging is the only method that allows one to record the activity of a dense neuronal population with single-cell resolution . The method consists in implanting a cranial imaging window, injecting a fluorescent calcium indicator dye that can be taken up by large numbers of neurons and finally recording the activity of neurons with time lapse calcium imaging using an in-vivo two photon microscope. Co-injection of astrocyte-specific dyes allows one to differentiate neurons from astrocytes. The technique can be performed in mice expressing fluorescent molecules in specific subpopulations of neurons to better understand the network interactions of different groups of cells.

To understand network dynamics of microcircuits in the neocortex, it is essential to simultaneously record the activity of a large number of neurons . In-vivo two-photon calcium imaging is the only method that allows one to record the activity of a dense neuronal population with single-cell resolution .

To understand network dynamics of microcircuits in the neocortex, it is essential to simultaneously record the activity of a large number of neurons .  ...

Biology

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.

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 ...

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.

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

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.

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.

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.

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 ...

Two-Photon and Wide-Field Calcium Imaging in the Superior Colliculus

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.

Author Spotlight: Unveiling Neural Coding and Mechanisms of Visual Processing in the Superior Colliculus 

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.

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

Real-Time Imaging for Neuron Activity in the Dentate Gyrus Cells of Mice 

In Vivo Calcium Imaging of Granule Cells in the Dentate Gyrus of Hippocampus in Mice

Real-time approaches are typically needed in studies of learning and memory, and in vivo calcium imaging provides the possibility to investigate neuronal activity in awake animals during behavior tasks. Since the hippocampus is closely associated with episodic and spatial memory, it has become an essential brain region in&#160;this field&#39;s research. In recent research, engram cells and place cells were studied by recording the neural activities in the hippocampal CA1 region using the miniature microscope in mice while performing behavioral tasks including open-field and linear track. Although the dentate gyrus is another important region in the hippocampus, it has rarely been studied with in vivo imaging due to its greater depth and difficulty for imaging. In this protocol, we present in detail a calcium imaging process, including how to inject the virus, implant a GRIN (Gradient-index) lens, and attach a base plate for imaging the dentate gyrus of the hippocampus. We further describe how to preprocess the calcium imaging data using MATLAB. Additionally, studies of other deep brain regions that require imaging may benefit from this method.

Author Spotlight: Investigating Neural Activity of Dentate Gyrus Granule Cells with Miniature Microscope

The dentate gyrus of the hippocampus carries out essential and distinct functions in learning and memory. This protocol describes a set of robust and efficient procedures for in vivo calcium imaging of granule cells in the dentate gyrus in freely moving mice.

Real-time approaches are typically needed in studies of learning and memory, and in vivo calcium imaging provides the possibility to investigate neuronal ...

Recording Neuronal Activity During Odor Plume Navigation with Miniscope Imaging

Miniscope Recording Calcium Signals at Hippocampus of Mice Navigating an Odor Plume

Mice navigate an odor plume with a complex spatiotemporal structure in the dark to find the source of odorants. This article describes a protocol to monitor behavior and record Ca2+ transients in dorsal CA1 stratum pyramidale neurons in the hippocampus (dCA1) in mice navigating an odor plume in a 50 cm x 50 cm x 25 cm odor arena. An epifluorescence miniscope focused through a gradient-index (GRIN) lens imaged Ca2+ transients in dCA1 neurons expressing the calcium sensor GCaMP6f in Thy1-GCaMP6f mice. The paper describes the behavioral protocol to train the mice to perform this odor plume navigation task in an automated odor arena. The methods include a step-by-step procedure for the surgery for GRIN lens implantation and baseplate placement for imaging GCaMP6f in CA1. The article provides information on real-time tracking of the mouse position to automate the start of the trials and delivery of a water reward. In addition, the protocol includes information on using an interface board to synchronize metadata describing the automation of the odor navigation task and frame times for the miniscope and a digital camera tracking mouse position. Moreover, the methods delineate the pipeline used to process GCaMP6f fluorescence movies by motion correction using the NorMCorre algorithm followed by identification of regions of interest with EXTRACT. Finally, the paper describes an artificial neural network approach to decode spatial paths from CA1 neural ensemble activity to predict mouse navigation of the odor plume.

Author Spotlight: Understanding Processing of Olfactory and Spatial Information by Brain with Real-Time Behavioral Analysis

This protocol investigates the brain-behavior relationship in hippocampal CA1 in mice navigating an odor plume. We provide a step-by-step protocol, including surgery to access imaging of the hippocampus, behavioral training, miniscope GCaMP6f recording and processing of the brain, and behavioral data to decode the mouse position from ROI neural activity.

Mice navigate an odor plume with a complex spatiotemporal structure in the dark to find the source of odorants. This article describes a protocol to ...

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

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In Vivo 2-Photon Calcium Imaging in Layer 2/3 of Mice

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Craniotomy Procedure for Visualizing Neuronal Activities in Hippocampus of Behaving Mice

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

Simultaneous Imaging of Microglial Dynamics and Neuronal Activity in Awake Mice

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

Calcium Imaging in Mouse Superior Colliculus

In Vivo Calcium Imaging of Granule Cells in the Dentate Gyrus of Hippocampus in Mice

Miniscope Recording Calcium Signals at Hippocampus of Mice Navigating an Odor Plume