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Cheek Injection Model for Simultaneous Measurement of Pain and Itch-related Behaviors
Published on: September 27, 2019
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Footedness for scratching itchy eyes in rodents
Yukitoshi Katayama1, Ayane Miura1,2, Tatsuya Sakamoto1
1Ushimado Marine Institute (UMI), Graduate School of Natural Science and Technology, Okayama University, Ushimado, Setouchi, Okayama 701-4303, Japan.
Proceedings. Biological Sciences
|October 19, 2022
Summary
Researchers identified gastrin-releasing peptide receptor (GRPR) neurons in the trigeminal system as crucial for transmitting itchy eye sensations in rodents. Depleting these neurons reduced scratching and eliminated foot preference, suggesting central control of laterality.
Area of Science:
- Neuroscience
- Sensory Biology
- Ophthalmology
Background:
- Neural mechanisms of eye itch are poorly understood compared to body itch.
- The trigeminal sensory system plays a role in facial sensations, including ocular discomfort.
Purpose of the Study:
- To investigate the neural pathways responsible for transmitting itch signals from the eyes.
- To explore the role of gastrin-releasing peptide receptor (GRPR) in ocular itch.
- To examine the laterality of scratching behavior in response to eye itch.
Main Methods:
- Histamine instillation into rodent conjunctival sacs to induce itch.
- Neural activation mapping in the trigeminal sensory system.
- Utilizing genetically modified rats with depleted GRPR-expressing neurons.
Main Results:
- GRPR neurons in the trigeminal system are essential for transmitting eye itch.
- Histamine induced ipsilateral neural activation but right-foot biased scratching behavior.
- Depletion of GRPR neurons reduced scratching and eliminated foot preference.
Conclusions:
- GRPR-expressing neurons are critical for eye itch transmission.
- Behavioral laterality in scratching is centrally generated and linked to foot preference.
- Findings offer insights into itch laterality mechanisms and potential therapies for eye disorders.
