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Updated: Nov 6, 2025

Morphological and Functional Evaluation of Ribbon Synapses at Specific Frequency Regions of the Mouse Cochlea
Published on: May 10, 2019
Cnr2 Is Important for Ribbon Synapse Maturation and Function in Hair Cells and Photoreceptors
Luis Colón-Cruz1, Roberto Rodriguez-Morales1, Alexis Santana-Cruz1
1Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico.
Cannabinoid receptor 2 (CNR2) is crucial for sensory synapse development in hair cells (HCs) and processing sensory information in developing larvae. Its absence severely impacts synaptic structure and function.
Area of Science:
- Neuroscience
- Sensory Biology
- Molecular Biology
Background:
- The function of cannabinoid receptor 2 (CNR2) in sensory epithelia is not well understood.
- Sensory hair cells (HCs) in the inner ear and lateral line (LL) are critical for detecting environmental stimuli.
Purpose of the Study:
- To investigate the role of CNR2 in the development and function of sensory synapses in HCs.
- To explore the impact of CNR2 on mechanotransduction and larval sensory behaviors.
Main Methods:
- Analysis of cnr2 expression in inner ear and LL hair cells.
- Examination of synaptic structure (presynaptic ribbons, CaV1.3 channels, PSDs) in cnr2-deficient larvae.
- Assessment of vesicular trafficking and larval swimming behaviors in response to auditory and light stimuli.
Main Results:
- Strong cnr2 expression was observed in HCs of the inner ear and LL.
- Loss of cnr2 led to severe perturbations in HC sensory synapses, including altered presynaptic ribbon and CaV1.3 channel distribution.
- Vesicular trafficking and mechanotransduction in HCs were disrupted, suggesting retrograde endocannabinoid system (ECS) modulation via CNR2.
- Similar synaptic defects were found in retinal ribbon synapses.
- Mutant larvae exhibited altered swimming behaviors following sound and light stimulation.
Conclusions:
- CNR2 plays a critical role in maintaining sensory synapse integrity and function in developing larvae.
- The endocannabinoid system, acting through CNR2, modulates HC mechanotransduction.
- CNR2 is essential for the processing of sensory information in the developing larval auditory and visual systems.
More Related Videos
11:45Postsynaptic Recordings at Afferent Dendrites Contacting Cochlear Inner Hair Cells: Monitoring Multivesicular Release at a Ribbon Synapse
Published on: February 10, 2011
09:24High-Resolution Quantitative Immunogold Analysis of Membrane Receptors at Retinal Ribbon Synapses
Published on: February 18, 2016
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