Related Experiment Videos
Deafness-induced plasticity in the mature central auditory system
S C Bledsoe1, S Nagase, J M Miller
1Department of Otolaryngology, University of Michigan, Ann Arbor 48109-0506, USA.
Neuroreport
|December 29, 1995
Summary
Deafness alters brain plasticity by reducing inhibitory neurotransmitter release, specifically gamma-aminobutyric acid (GABA), in the central auditory system. This impacts neuronal responsiveness and may explain central nervous system adaptations to sensory loss.
Area of Science:
- Neuroscience
- Auditory System Research
- Neuroplasticity
Background:
- Local changes in inhibitory neurotransmitters are implicated in deafness-induced plasticity within the mature central auditory system.
- Sensory deafferentation can induce plastic changes in the central nervous system.
Purpose of the Study:
- To investigate the role of inhibitory neurotransmitters in central auditory system plasticity following deafness.
- To examine changes in neuronal responsiveness and neurotransmitter release in the central nucleus of the inferior colliculus (CIC) after induced deafness.
Main Methods:
- Electrophysiological recordings and Fos-immunoreactivity in rats and guinea pigs.
- In vivo microdialysis to measure neurotransmitter release in the CIC.
- Induction of bilateral deafness for 21 days.
Main Results:
- Bilateral deafness increased evoked Fos-immunoreactive neurons in the CIC in response to contralateral cochlear stimulation.
- A significant reduction in CIC neurons responding with suppressed activity was observed in deafened animals.
- In vivo microdialysis showed a marked decrease in gamma-aminobutyric acid (GABA) release from CIC cells in deafened animals.
Conclusions:
- Local decreases in GABA release contribute to central auditory system plasticity following deafness.
- These findings suggest GABAergic system alterations are key to neuroplasticity induced by sensory deafferentation.