Name: two-photon calcium imaging in mice navigating a virtual reality environment
Uploaded: 2014-02-20T22:00:00
Description: Watch this Scientific Journal Video about Two-photon Calcium Imaging in Mice Navigating a Virtual Reality Environment at JoVE.com

This work was supported by the Friedrich Miescher Institute for Biomedical Research, the Max Planck Society, and the Human Frontiers Science Program.

All animal procedures were approved and carried out in accordance with guidelines of the Veterinary Department of the Canton Basel-Stadt.
1. Hardware and Software Setup
<ol>
	<li>Two-photon scanning microscope setup:
	<ol>
		<li>Use a pulsed infrared laser as an illumination source (pulse width &#60;120 fsec).</li>
		<li>Use a scan head composed of an 8 or 12 kHz resonant scanner and a standard galvanometer. Note: This enables frame rates of 40 or 60 Hz at 750 x 400 pixels. ...

<ol>
	<li>Helmchen, F., Fee, M. S., Tank, D. W., Denk, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Miniature+Head-Mounted+Two-Photon+MicroscopeHigh-Resolution+Brain+Imaging+in+Freely+Moving+Animals.">A Miniature Head-Mounted Two-Photon MicroscopeHigh-Resolution Brain Imaging in Freely Moving Animals.</a> Neuron. 31 (6), 903-912 (2001).</li><li>Dombeck, D. A., Khabbaz, A. N., Collman, F., Adelman, T. L., Tank, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+large-scale+neural+activity+with+cellular+resolution+in+awake,+mobile+mice.">Imaging large-scale neural activity with cellular resolution in awake, mobile mice.</a> Neuron. 56, 43-57 (2007).</li><li>Dombeck, D. A., Harvey, C. D., Tian, L., Looger, L. L., Tank, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+imaging+of+hippocampal+place+cells+at+cellular+resolution+during+virtual+navigation.">Functional imaging of hippocampal place cells at cellular resolution during virtual navigation.</a> Nat. Neurosci. 13 (11), 1433-1440 (2010).</li><li>Harvey, C. D., Coen, P., Tank, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Choice-specific+sequences+in+parietal+cortex+during+a+virtual-navigation+decision+task.">Choice-specific sequences in parietal cortex during a virtual-navigation decision task.</a> Nature. 484 (7395), 62-68 (2012).</li><li>Huber, D., Gutnisky, D. 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W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimization+of+a+GCaMP+Calcium+Indicator+for+Neural+Activity+Imaging.">Optimization of a GCaMP Calcium Indicator for Neural Activity Imaging.</a> J. Neurosci. 32 (40), 13819-13840 (2012).</li><li>Zhao, Y., Araki, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+expanded+palette+of+genetically+encoded+Ca2++indicators.">An expanded palette of genetically encoded Ca2+ indicators.</a> Science. 333 (6051), 1888-1891 (2011).</li><li>Mittmann, W., Wallace, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-photon+calcium+imaging+of+evoked+activity+from+L5+somatosensory+neurons+in+vivo.">Two-photon calcium imaging of evoked activity from L5 somatosensory neurons in vivo.</a> Nat. Neurosci. 14 (8), 1089-1893 (2011).</li><li>Katona, G., Szalay, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fast+two-photon+in+vivo+imaging+with+three-dimensional+random-access+scanning+in+large+tissue+volumes.">Fast two-photon in vivo imaging with three-dimensional random-access scanning in large tissue volumes.</a> Nat. Methods. 9 (2), 201-208 (2012).</li><li>Mank, M., Santos, A. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+genetically+encoded+calcium+indicator+for+chronic+in+vivo+two-photon+imaging.">A genetically encoded calcium indicator for chronic in vivo two-photon imaging.</a> Nat. Methods. 5 (9), 805-811 (2008).</li><li>Margolis, D. J., L&#252;tcke, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reorganization+of+cortical+population+activity+imaged+throughout+long-term+sensory+deprivation.">Reorganization of cortical population activity imaged throughout long-term sensory deprivation.</a> Nat. Neurosci. 15 (11), 1539-1546 (2012).</li><li>Zariwala, H. A., Borghuis, B. 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F., Plett, J., Mank, M., Griesbeck, O., Borst, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Virtual+Reality+for+Mice,+mousevr.blogspot.com.">Virtual Reality for Mice, mousevr.blogspot.com.</a> Nat. Neurosci. 13, 973-978 (2010).</li><li>Sakatani, T., Isa, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+analysis+of+spontaneous+saccade-like+rapid+eye+movements+in+C57BL/6+mice.">Quantitative analysis of spontaneous saccade-like rapid eye movements in C57BL/6 mice.</a> Neurosci. 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The key to the success of behavioral two-photon imaging is the stability of the preparation in two ways:
<ol>
	<li>Over the course of days post window implantation, inflammatory responses of the tissue can lead to enhancement of the formation of granulation tissue and cartilage that will hinder or even prevent imaging.</li>
	<li>During the experiment the brain has to be stable enough to prevent motion artifacts from corrupting neural activity related fluorescence signal.</li>
</ol>
To keep the...

Two-photon imaging of calcium indicators (genetically encoded like GCaMP57 or R-GECO8, or synthetic dyes like OGB or Fluo4) has emerged as a powerful method of measuring neuronal activity in behaving mice1-6. It enables the simultaneous measurement of the activity of hundreds of cells at near-single action potential resolution, up to approximately 800 &#181;m below the brain surface9,10. Moreover, using genetically encoded calcium indicators (GECIs) neuronal activity can be measured chronically5,11,12, and in genetically defined cell types13. Together, these methods provide a degree of temporal and spatial resolution that open up a multitude of new possibilities in the study of neuronal computation in vivo.
Surgical intervention is necessary to expose and label the mouse brain for imaging. Cells are typically transfected using a recombinant adeno-associated virus (AAV) system for GECI delivery and a cranial window is implanted over the injection site to gain optical access to the brain. A head bar is then attached to the skull for head fixation under the two-photon microscope. The design and implementation of these steps is critical as most of the problems with awake imaging arise from instabilities in the preparation. Ideally the procedure described here should allow for chronic imaging of up to several months following the surgery.
To enable visually guided behavior during two-photon imaging, the head fixed mouse sits on an air supported spherical treadmill, which it can use to navigate a virtual reality environment. Locomotion of the mouse on the treadmill is coupled to movement in the virtual environment that is displayed on a toroidal screen surrounding the mouse14,15. Behavioral variables such as locomotion, visual stimulus, and pupil position can be recorded6.
We describe the procedures involved in chronic two-photon imaging in mice exploring a virtual reality environment. The key points addressed are: reduction of movement artifacts, reduction of light leak, maximization of the number of simultaneously recorded cells, and minimization of photo damage. We also provide details on setting up the air-supported treadmill, pupil tracking, and the virtual reality environment. The procedures described here can be used for imaging fluorescently labeled cell populations in head fixed mice&#160;in a potentially wide variety of behavioral paradigms.

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		<col />
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	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">cover slips (d = 3-5 mm)</td>
			<td style="width:151px;">Menzel</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">window implant</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">InSight DeepSee laser</td>
			<td>Spectra-Physics</td>
			<td></td>
			<td>microscope</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">12kHz resonance scanner</td>
			<td>Cambridge Technology</td>
			<td>G1-003-30026</td>
			<td>microscope</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Galvometer</td>
			<td>Cambridge Technology</td>
			<td>G6215H</td>
			<td>microscope</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Digitizer</td>
			<td>National Instruments</td>
			<td>NI 5772</td>
			<td>microscope</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">FPGA</td>
			<td>National Instruments</td>
			<td>PXIe 7965R</td>
			<td>microscope</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Acquisition card</td>
			<td>National Instruments</td>
			<td>PCIe 6363</td>
			<td>microscope</td>
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		<tr height="20">
			<td height="20" style="height:20px;">Emission filter 525/50</td>
			<td>Semrock</td>
			<td>FF03-525/50-25</td>
			<td>microscope</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Piezo-electric z-drive</td>
			<td>Physikinstrumente</td>
			<td>P-726.1CD</td>
			<td>microscope</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Controller for piezo-electric drive</td>
			<td>Physikinstrumente</td>
			<td>E665 LVPZT</td>
			<td>microscope</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Objective 16x, 0.8NA</td>
			<td>Nikon</td>
			<td>CFI75</td>
			<td>microscope</td>
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		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Current amplifier</td>
			<td style="width:151px;">Femto</td>
			<td style="width:119px;">DHPCA-100</td>
			<td>microscope</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Photomultiplier tube</td>
			<td style="width:151px;">Hamamatsu</td>
			<td style="width:119px;"></td>
			<td>microscope</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">USB Camera without IR filter</td>
			<td>ImagingSource</td>
			<td>DMK22BUC03&#160;</td>
			<td>pupil tracking</td>
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		<tr height="20">
			<td height="20" style="height:20px;">Objective 50 mm</td>
			<td>ImagingSource</td>
			<td>M5018-MP&#160;</td>
			<td>pupil tracking</td>
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		<tr height="20">
			<td height="20" style="height:20px;">Macro adapter rings</td>
			<td>ImagingSource</td>
			<td>LAexSet</td>
			<td>pupil tracking</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Optical computer mouse</td>
			<td>Logitech</td>
			<td>G500</td>
			<td>motion tracking</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Styrofoam ball 20 cm</td>
			<td>e.g. idee-shop.de</td>
			<td>08797.00.15</td>
			<td>virtual environment</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">LED projector</td>
			<td>Samsung</td>
			<td>SP-F10M&#160;</td>
			<td>virtual environment</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Acquisition card</td>
			<td>National Instruments</td>
			<td style="width:119px;">NI 6009</td>
			<td>virtual environment</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Panda3D game engine</td>
			<td></td>
			<td><a href="http://www.panda3d.org/">www.panda3d.org</a></td>
			<td>virtual environment</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Numpy library for Python</td>
			<td style="width:151px;"></td>
			<td style="width:119px;"><a href="http://www.scipy.org/">www.scipy.org</a></td>
			<td>virtual environment</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Scipy library for Python</td>
			<td style="width:151px;"></td>
			<td style="width:119px;"><a href="http://www.scipy.org/">www.scipy.org</a></td>
			<td>virtual environment</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">NI-DAQmx driver</td>
			<td style="width:151px;">National Instruments</td>
			<td style="width:119px;"><a href="http://www.ni.com/">www.ni.com</a></td>
			<td>virtual environment</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:216px;">Ultrasound gel</td>
			<td style="width:151px;">Dahlhausen</td>
			<td style="width:119px;">5701.0342.10</td>
			<td>imaging</td>
		</tr>
	</tbody>
</table>

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.

The image quality in two-photon calcium imaging of cell populations labeled with a GECI largely depends on the quality of the cranial window implant. Two weeks following virus injection the cranial window should be inspected for clarity. There should be no granulation tissue or bone regrowth visible (Figure 1A). Moreover, the pattern of superficial blood vessels should remain unchanged and boundaries of the vasculature should be sharply defined. At the same time, GECI expression can also be checked. Boli...

Watch this Scientific Journal Video about Two-photon Calcium Imaging in Mice Navigating a Virtual Reality Environment at JoVE.com

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

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

two-photon-calcium-imaging-mice-navigating-virtual-reality

Research

JoVE Journal

Behavior

Development of a Virtual Reality Assessment of Everyday Living Skills

Cognitive impairments affect the majority of patients with schizophrenia and these impairments predict poor long term psychosocial outcomes.&#160; Treatment studies aimed at cognitive impairment in patients with schizophrenia not only require demonstration of improvements on cognitive tests, but also evidence that any cognitive changes lead to clinically meaningful improvements.&#160; Measures of &#8220;functional capacity&#8221; index the extent to which individuals have the potential to perform skills required for real world functioning. &#160;Current data do not support the recommendation of any single instrument for measurement of functional capacity.&#160; The Virtual Reality Functional Capacity Assessment Tool (VRFCAT) is a novel, interactive gaming based measure of functional capacity that uses a realistic simulated environment to recreate routine activities of daily living. Studies are currently underway to evaluate and establish the VRFCAT&#8217;s sensitivity, reliability, validity, and practicality.&#160;This new measure of functional capacity is practical, relevant, easy to use, and has several features that improve validity and sensitivity of measurement of function in clinical trials of patients with CNS disorders.

A challenge for proving treatment efficacy for cognitive impairments in schizophrenia is finding the optimizing measurement of skills related to everyday functioning.&#160; The Virtual Reality Functional Capacity Assessment Tool (VRFCAT) is an interactive gaming based computerized measure aimed at skills associated with everyday functioning, including baseline impairments and treatment related changes.

Cognitive impairments affect the majority of patients with schizophrenia and these impairments predict poor long term psychosocial outcomes.&#160; ...

A Protocol for Housing Mice in an Enriched Environment

Environmental enrichment (EE) is a housing environment for mice that boosts mental and physical health compared to standard laboratory housing. Our recent studies demonstrate that environmental enrichment decreases adiposity, increases energy expenditure, resists diet induced obesity, and causes cancer remission and inhibition in mice. EE typically consists of larger living space, a variety of &#8216;toys&#8217; to interact with, running wheels, and can include a number of other novel environmental changes. All of this fosters a more complex social engagement, cognitive and physical stimulations. Importantly, the toy location and type of toy is changed regularly, which encourages the mice to adapt to a frequently changing and novel environment. Many variables can be manipulated in EE to promote health effects in mice. Thus these approaches are difficult to control and must be properly managed to successfully replicate the associated phenotypes. Therefore, the goal of this video is to demonstrate how EE is properly set up and maintained to assure a complex, challenging, and controlled environment so that other researchers can easily reproduce the protective effects of EE against obesity and cancer.

Environmental enrichment for mice requires a complex and challenging setup, as well as comprehensive husbandry and handling techniques to assure robust metabolic and anti-cancer effects in the mice. This protocol provides detailed procedures to reproduce the above mentioned effects in mice.

Environmental enrichment (EE) is a housing environment for mice that boosts mental and physical health compared to standard laboratory housing. Our recent ...

Multifunctional Setup for Studying Human Motor Control Using Transcranial Magnetic Stimulation, Electromyography, Motion Capture, and Virtual Reality

The study of neuromuscular control of movement in humans is accomplished with numerous technologies. Non-invasive methods for investigating neuromuscular function include transcranial magnetic stimulation, electromyography, and three-dimensional motion capture. The advent of readily available and cost-effective virtual reality solutions has expanded the capabilities of researchers in recreating &#8220;real-world&#8221; environments and movements in a laboratory setting. Naturalistic movement analysis will not only garner a greater understanding of motor control in healthy individuals, but also permit the design of experiments and rehabilitation strategies that target specific motor impairments (e.g. stroke). The combined use of these tools will lead to increasingly deeper understanding of neural mechanisms of motor control. A key requirement when combining these data acquisition systems is fine temporal correspondence between the various data streams. This protocol describes a multifunctional system&#8217;s overall connectivity, intersystem signaling, and the temporal synchronization of recorded data. Synchronization of the component systems is primarily accomplished through the use of a customizable circuit, readily made with off the shelf components and minimal electronics assembly skills.

Transcranial magnetic stimulation, electromyography, and 3D motion capture are commonly used non-invasive techniques for investigating neuromuscular function in humans. In this paper, we describe a protocol that synchronously samples data generated by all three of these tools along with the unique addition of virtual reality stimulus presentation and feedback.

The study of neuromuscular control of movement in humans is accomplished with numerous technologies. Non-invasive methods for investigating neuromuscular ...

Using Virtual Reality to Transfer Motor Skill Knowledge from One Hand to Another

As far as acquiring motor skills is concerned, training by voluntary physical movement is superior to all other forms of training (e.g. training by observation or passive movement of trainee&#39;s hands by a robotic device). This obviously presents a major challenge in the rehabilitation of a paretic limb since voluntary control of physical movement is limited. Here, we describe a novel training scheme we have developed that has the potential to circumvent this major challenge. We exploited the voluntary control of one hand and provided real-time movement-based manipulated sensory feedback as if the other hand is moving. Visual manipulation through virtual reality (VR) was combined with a device that yokes left-hand fingers to passively follow right-hand voluntary finger movements. In healthy subjects, we demonstrate enhanced within-session performance gains of a limb in the absence of voluntary physical training. Results in healthy subjects suggest that training with the unique VR setup might also be beneficial for patients with upper limb hemiparesis by exploiting the voluntary control of their healthy hand to improve rehabilitation of their affected hand.

We describe a novel virtual-reality based setup which exploits voluntary control of one hand to improve motor-skill performance in the other (non-trained) hand. This is achieved by providing real-time movement-based sensory feedback as if the non-trained hand is moving. This new approach may be used to enhance rehabilitation of patients with unilateral hemiparesis.

As far as acquiring motor skills is concerned, training by voluntary physical movement is superior to all other forms of training (e.g. training by ...

Mobile Game-based Virtual Reality Program for Upper Extremity Stroke Rehabilitation

Stroke rehabilitation requires repetitive, intensive, goal-oriented therapy. Virtual reality (VR) has the potential to satisfy these requirements. Game-based therapy can promote patients&#39; engagement in rehabilitation therapy as a more interesting and a motivating tool. Mobile devices such as smartphones and tablet PCs can provide personalized home-based therapy with interactive communication between patients and clinicians. In this study, a mobile VR upper extremity rehabilitation program using game applications was developed. The findings from the study show that the mobile game-based VR program effectively promotes upper extremity recovery in patients with stroke. In addition, patients completed two weeks of treatment using the program without adverse effects and were generally satisfied with the program. This mobile game-based VR upper extremity rehabilitation program can substitute for some parts of the conventional therapy that are delivered one-on-one by an occupational therapist. This time-efficient, easy to implement, and clinically effective program would be a good candidate tool for tele-rehabilitation for upper extremity recovery in patients with stroke. Patients and therapists can collaborate remotely through these e-health rehabilitation programs while reducing economic and social costs.

Here, we present a protocol to develop and apply a mobile game-based virtual reality program for the recovery of upper limb dysfunction in patients with stroke. The present study shows that the mobile program is feasible and effectively promotes upper limb recovery in stroke patients.

Stroke rehabilitation requires repetitive, intensive, goal-oriented therapy. Virtual reality (VR) has the potential to satisfy these requirements. ...

A Method to Study Adaptation to Left-Right Reversed Audition

An unusual sensory space is one of the effective tools to uncover the mechanism of adaptability of humans to a novel environment. Although most of the previous studies have used special spectacles with prisms to achieve unusual spaces in the visual domain, a methodology for studying the adaptation to unusual auditory spaces has yet to be fully established. This study proposes a new protocol to set-up, validate, and use a left-right reversed stereophonic system using only wearable devices, and to study the adaptation to left-right reversed audition with the help of neuroimaging. Although individual acoustic characteristics are not yet implemented, and slight spillover of unreversed sounds is relatively uncontrollable, the constructed apparatus shows high performance in a 360&#176; sound source localization coupled with hearing characteristics with little delay. Moreover, it looks like a mobile music player and enables a participant to focus on daily life without arousing curiosity or drawing attention of other individuals. Since the effects of adaptation were successfully detected at the perceptual, behavioral, and neural levels, it is concluded that this protocol provides a promising methodology for studying adaptation to left-right reversed audition, and is an effective tool for uncovering the adaptability of humans to a novel environments in the auditory domain.

The present study proposes a protocol to investigate the adaptation to left-right reversed audition achieved only by wearable devices, using neuroimaging, which can be an effective tool for uncovering the adaptability of humans to a novel environment in the auditory domain.

An unusual sensory space is one of the effective tools to uncover the mechanism of adaptability of humans to a novel environment. Although most of the ...

Measuring the Kinematics of Daily Living Movements with Motion Capture Systems in Virtual Reality

The inability to complete instrumental activities of daily living (IADL) is a precursor to various neuropsychological diseases. Questionnaire-based assessments of IADL are easy to use but prone to subjective bias. Here, we describe a novel virtual reality (VR) test to assess two complex IADL tasks: handling financial transactions and using public transportation. While a participant performs the tasks in a VR setting, a motion capture system traces the position and orientation of the dominant hand and head in a three-dimensional Cartesian coordinate system. Kinematic raw data are collected and converted into &#39;kinematic performance measures,&#39; i.e., motion trajectory, moving distance, and time to completion. Motion trajectory is the path of a particular body part (e.g., dominant hand or head) in space. Moving distance refers to the total distance of the trajectory, and time to completion is how long it took to complete an IADL task. These kinematic measures could discriminate patients with cognitive impairment from healthy controls. The development of this kinematic measuring protocol allows detection of early IADL-related cognitive impairments.

We designed a virtual reality test to assess instrumental activities of daily living (IADL) with a motion capture system. We propose a detailed kinematic analysis to interpret the participant&#39;s various movements, including trajectory, moving distance, and time to completion to evaluate IADL capabilities.

The inability to complete instrumental activities of daily living (IADL) is a precursor to various neuropsychological diseases. Questionnaire-based ...

A Networked Desktop Virtual Reality Setup for Decision Science and Navigation Experiments with Multiple Participants

Investigating the interactions among multiple participants is a challenge for researchers from various disciplines, including the decision sciences and spatial cognition. With a local area network and dedicated software platform, experimenters can efficiently monitor the behavior of the participants that are simultaneously immersed in a desktop virtual environment and digitalize the collected data. These capabilities allow for experimental designs in spatial cognition and navigation research that would be difficult (if not impossible) to conduct in the real world. Possible experimental variations include stress during an evacuation, cooperative and competitive search tasks, and other contextual factors that may influence emergent crowd behavior. However, such a laboratory requires maintenance and strict protocols for data collection in a controlled setting. While the external validity of laboratory studies with human participants is sometimes questioned, a number of recent papers suggest that the correspondence between real and virtual environments may be sufficient for studying social behavior in terms of trajectories, hesitations, and spatial decisions. In this article, we describe a method for conducting experiments on decision-making and navigation with up to 36 participants in a networked desktop virtual reality setup (i.e., the Decision Science Laboratory or DeSciL). This experiment protocol can be adapted and applied by other researchers in order to set up a networked desktop virtual reality laboratory.

This paper describes a method for conducting multi-user experiments on decision-making and navigation using a networked computer laboratory.

Investigating the interactions among multiple participants is a challenge for researchers from various disciplines, including the decision sciences and ...

Virtual Reality Experiments with Physiological Measures

Virtual reality (VR) experiments are increasingly employed because of their internal and external validity compared to real-world observation and laboratory experiments, respectively. VR is especially useful for geographic visualizations and investigations of spatial behavior. In spatial behavior research, VR provides a platform for studying the relationship between navigation and physiological measures (e.g., skin conductance, heart rate, blood pressure). Specifically, physiological measures allow researchers to address novel questions and constrain previous theories of spatial abilities, strategies, and performance. For example, individual differences in navigation performance may be explained by the extent to which changes in arousal mediate the effects of task difficulty. However, the complexities in the design and implementation of VR experiments can distract experimenters from their primary research goals and introduce irregularities in data collection and analysis. To address these challenges, the Experiments in Virtual Environments (EVE) framework includes standardized modules such as participant training with the control interface, data collection using questionnaires, the synchronization of physiological measurements, and data storage. EVE also provides the necessary infrastructure for data management, visualization, and evaluation. The present paper describes a protocol that employs the EVE framework to conduct navigation experiments in VR with physiological sensors. The protocol lists the steps necessary for recruiting participants, attaching the physiological sensors, administering the experiment using EVE, and assessing the collected data with EVE evaluation tools. Overall, this protocol will facilitate future research by streamlining the design and implementation of VR experiments with physiological sensors.

Virtual reality (VR) experiments can be difficult to implement and require meticulous planning. This protocol describes a method for the design and implementation of VR experiments that collect physiological data from human participants. The Experiments in Virtual Environments (EVE) framework is employed to accelerate this process.

Virtual reality (VR) experiments are increasingly employed because of their internal and external validity compared to real-world observation and ...

Longitudinal Two-Photon Imaging of Dorsal Hippocampal CA1 in Live Mice

Two-photon microscopy is a fundamental tool for neuroscience as it permits investigation of the brain of live animals at spatial scales ranging from subcellular to network levels and at temporal scales from milliseconds to weeks. In addition, two-photon imaging can be combined with a variety of behavioral tasks to explore the causal relationships between brain function and behavior. However, in mammals, limited penetration and scattering of light have limited two-photon intravital imaging mostly to superficial brain regions, thus precluding longitudinal investigation of deep-brain areas such as the hippocampus. The hippocampus is involved in spatial navigation and episodic memory and is a long-standing model used to study cellular as well as cognitive processes important for learning and recall, both in health and disease. Here, a preparation that enables chronic optical access to the dorsal hippocampus in living mice is detailed. This preparation can be combined with two-photon optical imaging at cellular and subcellular resolution in head fixed, anesthetized live mice over several weeks. These techniques enable repeated imaging of neuronal structure or activity-evoked plasticity in tens to hundreds of neurons in the dorsal hippocampal CA1. Furthermore, this chronic preparation can be used in combination with other techniques such as micro-endoscopy, head-mounted wide field microscopy or three-photon microscopy, thus greatly expanding the toolbox to study cellular and network processes involved in learning and memory.

This method describes a chronic preparation that allows optical access to the hippocampus of living mice. This preparation can be used to perform longitudinal optical imaging of neuronal structural plasticity and activity-evoked cellular plasticity over a period of several weeks.

Two-photon microscopy is a fundamental tool for neuroscience as it permits investigation of the brain of live animals at spatial scales ranging from ...