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Published on: August 18, 2020
The precise temporal pattern of prehearing spontaneous activity is necessary for tonotopic map refinement
Amanda Clause1, Gunsoo Kim2, Mandy Sonntag3
1Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Center for the Neural Basis of Cognition, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
Spontaneous activity patterns in the developing auditory system are crucial for establishing precise tonotopy. Blocking cholinergic neurotransmission impaired synaptic development and axonal pruning in knockout mice.
Area of Science:
- Neuroscience
- Auditory System Development
- Sensory Pathway Development
Background:
- Patterned spontaneous activity is essential in developing sensory systems.
- Rhythmic bursts in cochlear hair cells travel through auditory pathways.
- The role of this activity in central auditory circuit development is unclear.
Purpose of the Study:
- To investigate the role of efferent cholinergic neurotransmission in shaping spontaneous activity patterns.
- To determine the impact of altered activity patterns on the development of central auditory circuits.
Main Methods:
- Utilized alpha9 nicotinic acetylcholine receptor knockout (α9 KO) mice.
- Blocked efferent cholinergic neurotransmission to developing hair cells.
- Assessed functional and structural changes in the inhibitory tonotopic map.
Main Results:
- α9 KO mice exhibited altered temporal fine structure of spontaneous activity.
- Significant impairments in synaptic strengthening and silencing of connections were observed.
- Axonal pruning was notably absent in KO mice, indicating developmental deficits.
Conclusions:
- Precise temporal patterns of spontaneous activity are critical before hearing onset.
- This activity is essential for establishing tonotopy in central auditory pathways.
- Cholinergic pathways play a key role in auditory map refinement.
