Mapping Motor Circuit Mechanisms During Voluntary Movement

Mapping Motor Circuit Mechanisms During Voluntary Movement

Several users of our O’Hara behavioral testing systems are presenting their research at SfN.

Matsuzaki and colleagues at the University of Tokyo are investigating the role of primary and secondary motor cortices in information processing during self-initiated versus externally triggered movements. To do this they are using the TaskForcer for mice in combination with in vivo widefield two-photon imaging. Below is a summary of what they plan to present at SFN.

Voluntary motor movements can either be self-initiated, or externally triggered. Neuronal ensembles in the primary (M1) and secondary (M2) both play a role in information processing during voluntary movement, but the relative contribution of each remains unclear. Furthermore, how each region processes information when the same movement is self-initiated (SI) versus externally triggered (ET) remains unknown. Terada and colleagues in the Matsuzaki lab examined whether the pattern of activation differed in M2 compared to M1 during SI and ET movements. They hypothesized that the presence of external stimuli would be sufficient to alter neural activity patterns in M2 when the same movement was self-initiated versus externally triggered. To test this, they trained head-fixed mice to perform a self-initiated lever-pull task (SI) and an external cue-triggered lever-pull task (ET) using the TaskForcer. During task performance, they conducted calcium imaging of GcAMP infected layer 2/3 neurons concurrently in M2 and M1 using super-wide-field two-photon microscopy (Terada et al., 2018) in mice implanted with large cranial windows.
They found that the proportion of neurons that responded to movement-related activity specific to either learning type was greater in M2 compared to M1. Furthermore, calcium activity in M2 was differed significantly between the self-initiated and externally triggered trials, indicating that external stimuli are sufficient to drive differential neuronal responses in M2. These results also suggested that M2 can distinguish between learning trials even when the same body part is initiated.

To learn more about Terada and colleagues application of the TaskForcer check out their poster at SFN or visit our booth # 1502!

Abstract Citation

*S.-I. TERADA1, K. KOBAYASHI2, M. MATSUZAKI1
1The Univ. of Tokyo, Tokyo, Japan;2Natl. Inst. For Physiological Sci., Okazaki, Japan. Neural dynamics in the mouse secondary and primary motor cortices during self-initiated and externally triggered movements. Program No. 081.05. 2019 Neuroscience Meeting Planner. Chicago, IL: Society for Neuroscience, 2019. Online.

TaskForcer: Restraint Chamber for Operant Conditioning

Wireless Fiber Photometry: Measuring Neurochemicals In Vivo in Real Time

Wireless Fiber Photometry: Measuring Neurochemicals In Vivo in Real Time

Amuza and Teleopto launch the first commercial wireless fiber photometry system at Neuroscience 2019

Our wireless optogenetic users have frequently asked us if we could provide wireless photometry – we are happy to announce that now we can!

TeleFipho wireless headstages allow your freely behaving animals to move with true freedom, enabling novel experimental approaches with fiber photometry. The 3 gram headstages are optimized for GCaMP and other GFP based indicators.

 

TeleFipho includes all of the components required for fiber photometry – light source, filter cube, photodetector, and wireless transmission hardware – in a 3 gram headstage.

What is Fiber Photometry?

Fiber Photometry is a powerful technique for measuring rapid changes in neuromodulators in vivo via fluorescence. It is most commonly used  to measure fast (subsecond) changes in concentrations of calcium in freely behaving animals, but it is now also capable of being used to monitor neurotransmitters and other molecules.To use fiber photometry, genetically encoded fluorescent indicators are first expressed at the location of interest. When excited by light of the right wavelength, these proteins fluoresce – but only while they are bound to their target analyte. As local concentrations of the analyte rise and fall, the fluorescence intensity rises and falls in response. Genetically encoded calcium indicators (GECIs), such as GcAMP have been the mainstay of fiber photometry and also for calcium imaging, a closely related technique. Recently dopamine indicators (Dlight1, GRABDA) and norepinephrine indicators (GRABNE) have been introduced, and more neurochemical sensors are in development. 

To capture this signal  in vivo, an optical fiber is implanted at the target region in the animal. The other end of the fiber is attached to the photometry hardware. First an LED or laser light source passes light through the fiber to excite the indicator proteins in the target region. The resulting fluorescent light then travels back through the fiber to a photodetector, creating a record of the changing concentrations of the analyte. Careful filtering and splitting of the light traveling through the fiber optic is required to separate the light used for excitation from the fluorescence being sent to the photodetector. 

Why use Fiber Photometry?

The most frequent use is to measure changes in calcium levels at synapses as a proxy for changes in neural activity, helping researchers discern the links between behavior states and the firing patterns of neurons. But the same technique is also used to monitor the activity of GPCRs and ion channel drug targets. 

When used with freely moving animals, fiber optic tethers can be problematic. The cable can prevent animals from using exercise wheels or shelters or get tangled in complicated environments, limiting behavioral testing. Cables can also cause artifacts when used with video tracking software. For example, the cable often continues to sway after the animal has stopped moving, making it difficult to recognize freezing behavior during fear conditioning studies. Placing all of the necessary components for fiber photometry in a small lightweight headstage ends these problems.

TeleFipho has been tested with both mice and rats. The data above shows stress induced (tail pinch) changes in GCaMP signals from hypothalamic orexin neurons in mice. GCaMP is a genetically encoded calcium indicator often used to monitor calcium dynamics. Data is Courtesy of Dr. Daisuke Ono in the Akihiro Yamanaka Lab, Nagoya University.

Shrinking the components for fiber photometry has an added bonus: it also allows us to shrink the price. Telefipho starts at roughly half of the cost of other commercial fiber photometry systems.

Please stop by our booth during SfN 2019 to ask for a demonstration and visit our product page for more information.

Understanding how the Visual System Influences Perceptual Decision Making

Understanding how the Visual System Influences Perceptual Decision Making

Several users of our O’Hara behavioral testing systems are presenting their research at SfN 2019 this year!
Check out what they’ve been working on.

Benucci and colleagues at RIKEN Center for Brain Science are currently investigating how neural networks in the visual system interact with environmental cues during the decision making process using the Self Head-Restraining Platform for mice. Below is a summary of what they plan to present at SFN2019

The role of neural networks within the visual system in guiding perceptual decision making processes is largely unknown.  Orlandi and colleagues in Dr. Andrea Benucci’s lab hypothesized that neuronal activation in visual cortices was necessary to provide predictive information about either the animals’ choices or task outcome (or both) during the decision making process. To test this, they analyzed calcium signals of GCaMP infected neurons in mice implanted with cranial windows over occipital-parietal cortical areas as they performed a two-alternative forced choice orientation discrimination task (See an example of the task below). By using large cranial windows, Orlandi and colleagues had optical access to between 10-12 cortical areas at the same time, allowing them to visualize signals from large-scale and distributed neural networks within the visual system. What they found was that large-scale activations of occipital-parietal visual areas did in fact hold predictive information about the animal’s decision.

Example of the two-alternative forced choice orientation discrimination task

Self Head-Restraining Platform: An automated platform with voluntary head fixation

Example of GCaMP expression in mouse cortex. Adapted from the Britt Lab at McGill University

To learn more about Benucci’s research application of the Self Head-Restraining Platform, check out his poster at SFN this year! And Stop by our booth # 1502!

Abstract Citation

*J. G. ORLANDI1, S. GRZELKOWSKI2,1, M. ABDOLRAHMANI1, R. AOKI1, D. LYAMZIN1, A. BENUCCI1;
1Lab. for Neural Circuits and Behavior, RIKEN Ctr. for Brain Sci., Wakoshi, Japan; 2FNWI, Univ. van Amsterdam, Amsterdam, Netherlands. Network interactions in the mouse visual cortex are predictive of perceptual decisions. Program No. 751.14. 2019 Neuroscience Meeting Planner. Chicago, IL: Society for Neuroscience, 2019. Online.

Amuza at SfN 2018

Amuza at SfN 2018

 

 

Amuza will present at SfN 2018. Our behavioral system, neurotransmitter collection and detection system, and wireless optogenetics products will be on display at our booth #3127. The behavioral system from O’Hara has a lot of new features you might have never seen. Our booth this time will be 40 feet long which is the largest sized booth we have ever had since the year 2000.

Please stop by to discuss about our new products and get technical support directly from our product experts.