| Autor: |
De Faveri, F., Ceriani, F., Marcotti, W. |
| Předmět: |
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| Zdroj: |
Journal of Hearing Science; Sep2024, Vol. 14 Issue 3, p130-130, 1/2p |
| Abstrakt: |
Introduction: Sensory-independent calcium activity regulates the development of mammalian sensory systems. Our current understanding of the origin and modulation of these calcium signals comes from ex vivo experimental work, which cannot replicate the sophisticated anatomy, innervation and physiology of the intact mammalian cochlea. We have developed surgical and microscopy approaches that, combined with transgenic animals expressing fluorescent indicators, allow us to study how mammalian sensory hair cells operate in vivo. Using this approach, we investigated the dynamics of spontaneous calcium activity in the prehearing cochlea of live mice at the cellular level. Material and methods: Mice (P3-P10) expressing the genetically encoded calcium indicator GCaMP6f in either the hair cells or the supporting cells were anaesthetised using isoflu-rane and their body temperature maintained with a heat mat. The surgical procedure only led to a very small opening in the apical coil of the cochlear bone, leaving the cochlear canals intact and unopened. The mouse was then transferred on the stage of a two-photon microscope equipped with long working distance water immersion objectives for imaging. Results: This approach allowed us to record from the same cochlear region spanning 15-30 IHCs. We found that IHCs and supporting cells displayed spontaneous calcium activity in vivo throughout the age-range investigated. IHC activity mostly appeared in bursts and some IHCs appeared to transition between quiescent periods and periods of prolonged spontaneous activity. Nearby IHCs displayed both independent and coordinated activity, which was compatible with the modulation on IHC excitability by calcium waves from the supporting cells. Conclusions: Our approach provides significant insights into the nature of spontaneous cochlear activity in prehear-ing mice. These findings provide the first in vivo physiological recordings of spontaneous calcium activity occurring in the mouse pre-hearing cochlea. The application of two-photon imaging to study cochlear activity in vivo offers a promising avenue for future research. [ABSTRACT FROM AUTHOR] |
| Databáze: |
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