Reversal of Age-Related Changes in Cortical Sound-Azimuth Selectivity with Training

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Aging Research

Background:

• Aging impairs speech perception and sound localization.
• Age-related deficits in cortical neural timing, linked to speech perception, are partially reversible with auditory training.
• The impact of training on age-related cortical changes in spatial processing remains unstudied.

Purpose of the Study:

• To investigate if auditory training can reverse age-related deficits in cortical spatial processing.
• To examine the effects of a sound-azimuth discrimination task on spatial tuning in aged rats.

Main Methods:

• ~21-month-old rats were trained on a sound-azimuth discrimination task for 1 month.
• Cortical spatial processing and inhibitory interneuron populations were analyzed.
• A control group of age-matched untrained rats was used.
• A passive sound exposure group controlled for non-task-related sound effects.

Main Results:

• One month of auditory training significantly improved cortical sound-azimuth tuning in aged rats compared to untrained controls.
• Training led to increased cortical parvalbumin-labeled inhibitory interneurons.
• Passive sound exposure without task demands did not alter cortical spatial processing.

Conclusions:

• Behavioral training can reverse age-related declines in central neural processing related to spatial auditory perception.
• The findings highlight the plasticity of the aging brain and the potential for auditory training to mitigate hearing loss.
• This study provides a foundation for using behavioral interventions to enhance auditory function in aging populations.