On the role of the auditory critical bands in effects of stimulus-specific adaptation in the activity of primary auditory cortex neurons in awake mice

The neurophysiological effects of stimulus-specific adaptation in the single neurons’ activity in the primary fields of the awake house mice auditory cortex were firstly studied. While adaptation of neuronal responses to sound sequences consisting of four identical tones, the time intervals between which were selected so as to be similar to the temporal structure of series of mouse pups wriggling call, adult females were stimulated by a fifth tone signal, the frequency of which differed from the frequency of the first four tone pulses in the series. The presentation of deviant tone led to a complete or partial neuronal responses recovery from adaptation in responses to the fifth component of the sequence, i.e. the response to the fifth tone was stronger than ones to the 2nd – 4th signals. Localization of the frequencies of main tonal sequence components and of the deviant one in two different non-overlapping critical bands of mouse hearing was followed by the most prominent effect of release from stimulus-specific adaptation. Thus, the critical band mechanism is involved in facilitating of the novelty responses of auditory neurons in the midbrain and auditory cortex.