Early-Life Stress Impairs Perception and Neural Encoding of Rapid Signals in the Auditory Pathway

In children, early ear infections are a risk factor for later speech perception deficits. This is likely because auditory deprivation during a developmental critical period (CP) induces long-lasting deficits in perception and ACx encoding of temporally-varying sounds. CPs also create susceptibility to early-life stress (ELS) in neural regions involved with cognition and anxiety. As CP mechanisms are shared by sensory cortices and higher neural regions, ACx and temporal encoding may also be susceptible to ELS. To examine the effects of ELS on temporal processing, we developed a model of ELS in the Mongolian gerbil, a well-established model for auditory processing. ELS induction impaired the behavioral detection of short gaps in sound, which are critical for speech perception. This was accompanied by reduced neural responses to gaps in ACx, the auditory periphery, and auditory brainstem. These ELS effects presumably degrade the fidelity of sensory representations available to higher regions, and could contribute to ELS-induced problems with cognition.