In vivo Calcium Imaging of Mouse Geniculate Ganglion Neuron Responses to Taste Stimuli

Bryan E. Fowler; Lindsey J. Macpherson

doi:10.3791/62172

In vivo Calcium Imaging of Mouse Geniculate Ganglion Neuron Responses to Taste Stimuli

JoVE Journal
Neuroscience

A subscription to JoVE is required to view this content. Sign in or start your free trial.

JoVE Journal Neuroscience

In vivo Calcium Imaging of Mouse Geniculate Ganglion Neuron Responses to Taste Stimuli

Full Text

5,613 Views

07:27 min

February 11, 2021

DOI: 10.3791/62172-v

Bryan E. Fowler¹, Lindsey J. Macpherson¹

¹Department of Biology,The University of Texas at San Antonio

Overview

This study outlines a technique for exposing the geniculate ganglion of a live, anesthetized laboratory mouse to measure neuronal responses to taste stimuli using calcium imaging. This approach enables researchers to conduct multiple trials with different tastants, facilitating in-depth comparisons of neuronal activation.

Key Study Components

Area of Science

Neuroscience
Neuroimaging
Taste perception

Background

The geniculate ganglion is a vital component of the chorda tympani taste pathway.
Understanding neuronal responses to taste stimuli can provide insights into taste processing.
Calcium imaging allows for the monitoring of multiple individual neurons simultaneously.
This technique surpasses traditional electrophysiological methods in cell count per trial.

Purpose of Study

To develop a methodology for exposing the geniculate ganglion in vivo for real-time imaging.
To investigate neuronal responses to different taste stimuli.
To enhance the understanding of taste processing at the neuronal level.

Methods Used

Utilization of a laboratory mouse model to conduct in vivo calcium imaging.
Exposure of the geniculate ganglion through surgical dissection.
Application of different taste stimuli while monitoring neuronal responses using GCaMP fluorescence.
Careful steps were taken to ensure minimal damage or bleeding during the procedure.
Visual responses were analyzed through video footage to assess changes in fluorescence.

Main Results

Taste stimuli resulted in a rapid increase in GCaMP fluorescence among the responding neurons.
Analysis of fluorescence changes allowed for identification of neuronal responses to various tastants.
Successful visualization and measurement of neuronal activity were achieved, highlighting key responses.
Findings validate the effectiveness of calcium imaging for studying taste neuron functionality.

Conclusions

This study demonstrates a robust methodology for examining neuronal responses to taste stimuli.
The approach provides valuable insights into neuronal mechanisms underlying taste perception.
Overall, it enhances our understanding of the functional role of the geniculate ganglion in taste processing.

Frequently Asked Questions

What are the advantages of using this imaging technique?

This method allows monitoring of multiple neurons simultaneously, providing detailed insights into neuronal activity in response to various tastants.

How is the geniculate ganglion exposed in the study?

The ganglion is exposed through a surgical procedure involving incisions and careful dissection to avoid damaging surrounding tissues.

What type of data is obtained during this process?

Researchers gather real-time fluorescence data that indicates neuronal responses to specific taste stimuli, allowing for analysis of activity patterns.

Can this method be applied to other types of sensory neurons?

Yes, the approach can be adapted for other sensory modalities by targeting relevant ganglia and stimuli specific to those senses.

What are the key limitations of this study?

Care must be taken to minimize tissue damage and bleeding; these factors may affect the consistency and reliability of results.

Here we present how to expose the geniculate ganglion of a live, anesthetized laboratory mouse and how to use calcium imaging to measure the responses of ensembles of these neurons to taste stimuli, allowing for multiple trials with different stimulants. This allows for in depth comparisons of which neurons respond to which tastants.

This technique can answer important functional questions about neuronal responses to taste in the geniculate ganglia, a crucial part of the interior chorda tympani taste pathway. This technique can be used to monitor the real-time reactions of multiple individual neurons in a single experimental trial, as cells recorded per animal are significantly higher than typically observed via the electrophysiological method. With the headpost-mounted mouse in the supine position on a heating pad, make a two centimeter midline incision in the skin over the throat, from the sternum to the chin.

And retract the skin and sub-maxillary glands to fully expose the digastric muscles. After locating the seam in the paratracheal musculature, separate the seam with blunt dissection and retract the tissue to open it. Carefully cut an opening in the top of the trachea large enough to fit a piece of polyethylene tubing without cutting more than halfway through the diameter of the trachea and insert the tubing into the trachea toward the lungs.

View the full transcript and gain access to thousands of scientific videos