Auditory Processing Remains Sensitive to Environmental Experience

This study induced transient hearing loss (HL) spanning adolescence in jirds to determine whether behavioral and neural maturation are disrupted. A total of 46 Mongolian jirds (24 females and 22 males) were used in the study. To determine whether auditory function is vulnerable during adolescence, transient HL was induced with earplugs at postnatal day 23 (P23), after a well-defined auditory cortex (AC) critical period ended. Normal hearing was restored by removing earplugs at P102, after the animals had passed through adolescence and reached sexual maturity. To confirm the time course of sexual maturation, testosterone levels were tracked across development, both in normal-hearing animals (n = 12) and littermates with transient auditory deprivation during adolescence (n = 14).

After transient HL and earplug removal at P102, jirds recovered for 21 days prior to behavioral training on the amplitude modulation depth detection task. All behavioral experiments were performed in a sound-attenuating booth and were observed through a closed-circuit video monitor. Following behavioral assessment, a subset of animals (Control: n = 7; HL: n = 9) were implanted with a multichannel electrode array in the primary AC. Auditory brainstem responses (ABRs) were collected from control (n = 12) and adolescent HL (n = 13) animals to determine whether the long duration of earplug insertion resulted in changes to the auditory periphery. In addition, a subset of animals (Control: n = 5; HL: n = 5) were used for in vitro AC recordings. The dataset contains behavioral, in vitro physiology, electrophysiology, hormonal, and ABR data.