Fig 1.
Arrangement of electrodes and AEP waveforms recorded from different cortical areas.
A. Twelve straw electrodes were symmetrically placed over the frontal, parietal and occipital areas; one electrode was placed over the olfactory area as a reference electrode, and one electrode was placed over the cerebellum as a ground electrode. B. An expanded drawing of the area in the dashed box in the left figure. The waveforms represent the responses to the first sound recorded from different cortical areas in a waking rat. The arrows indicate the N1 component peaks, and the arrow heads indicate the peaks of the positive component (P1) before the N1 component.
Table 1.
N1 latencies, amplitudes of conditioning and test sounds and values of sensory gating (TAMP/CAMP) in different cortical areas in waking rats.
Fig 2.
Auditory sensory gating during waking, NREM sleep and REM sleep in different cortical areas.
A. The AEP waveforms to the Conditioning-testing paradigm sound stimuli during waking, NREM sleep and REM sleep in different cortical areas are shown. Blue and red AEP waveforms were evoked by the conditioning and test sounds, respectively; the dotted line indicates the start of the sound stimuli. The green rectangle indicates the substantial changes in the sensory gating and AEP waveforms in the frontal and parietal areas during NREM sleep. B. The T/C values of the left cortical areas during waking, NREM and REM sleep. The data indicate that auditory sensory gating was effected by vigilant states in the frontal and parietal areas (F1, F3, P1, and P3), but not in the occipital areas (O1 and O3). Moreover, auditory sensory gating recorded in NREM sleep, but not in REM sleep, was decreased (the ratio of T/C increased) from waking in the cortical areas F1,F3 and P1. The data are expressed as the mean ± SEM; “*” represents P<0.05, one-way repeated-measures ANOVA, with Bonferroni correction post hoc tests.
Fig 3.
Changes in the N1 latencies and amplitudes of the conditional and test sounds in different cortical areas during different vigilant states.
A,B. Latencies of the conditional sound (CLATs) (A) and test sound (TLATs) (B) in different cortical areas during waking, NREM sleep and REM sleep. C,D. Amplitudes of the conditional sound (CAMPs) and test sound (TAMPs) in different cortical areas during waking, NREM sleep and REM sleep. E. The percentages of increments in the TAMPs and CAMPs from waking to NREM sleep in different cortical areas. The data indicate that the CLAT, TLAT, CAMP and TAMP were affected by the vigilant state in the frontal and parietal areas (F1, F3, P1 and P3), but not in the occipital areas (O1 and O3). The data are expressed as the mean ± SEM; “*” represents P<0.05, “**” represents P<0.01, one-way repeated-measures ANOVA, with Bonferroni correction post hoc tests.