Large-Scale Networks for Auditory Sensory Gating in the Awake Mouse.

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Sensory Processing

Background:

• Auditory sensory gating (ASG) reduces brain response to repeated sounds.
• ASG is altered in psychiatric conditions like schizophrenia.
• Mechanisms of ASG remain poorly understood, especially beyond early cortical responses.

Purpose of the Study:

• Investigate ASG mechanisms in awake mice across the brainstem-to-cortex pathway.
• Examine ASG at variable interstimulus intervals (ISIs) from 125 to 2000 ms.
• Clarify the duration of ASG and the stability of sensory-evoked brain states.

Main Methods:

• Utilized high-density electroencephalography (EEG) and intracerebral recordings in awake mice.
• Recorded brain responses to auditory stimuli (T1 and T2) at varying ISIs.
• Analyzed scalp EEG topographies and neural activity from brainstem to cortex.

Main Results:

• ASG was observed at ISIs from 125 ms to 2000 ms, persisting longer than previously assumed.
• First tone (T1) evoked stable brain states lasting ~350 ms, unaffected by the second tone (T2).
• ASG was present from the ventral cochlear nucleus (vCN) upwards, amplifying along the auditory pathway.

Conclusions:

• ASG has a longer duration and involves more extended brain state stability than previously recognized.
• Ongoing neural network activity, rather than just early evoked potentials, influences ASG.
• ASG generators are distributed from the brainstem to the cortex, with bottom-up amplification and potential top-down interactions.