Fig. 2
Pharmacological analysis of caffeine-assisted oscillation elicited by intra-cortical stimulation in the OSC, focusing on GABAB receptors. An optical recording method was applied. All recordings were performed in caffeine-containing medium. A Optical image acquired at a time latency of 310.8 ms is superimposed on the slice illustration. The image includes a high-activity area during one course of oscillation (as shown in B). Note that the high-activity area that emerged repeatedly is considered the origin of oscillatory activities. The location of oscillatory origin was thus confirmed to be in the upper layer of the somatosensory cortex, as indicated by the indicated by the arrow. B One time-course response of the optical signal obtained at the oscillatory origin (as shown in A). Note that the local area shown in A with the asterisk generated the wave with the asterisk in B. C Time-course response after application of baclofen in caffeine-containing medium. Note that the oscillatory phase completely disappeared, but the initial phase did not. The initial slope and peak amplitude of the initial wave were slightly decreased as compared with those before the application of baclofen, and slight depolarization continued during the later phase. D Time-course response after further application of CNQX in medium containing both caffeine and baclofen. Note that most of the initial wave disappeared. E The 3 time-course responses shown in B–D are superimposed, and the temporal axis is expanded