Spontaneous, rhythmic potentials recorded from the vitreous cavity of urethane-anesthetized rats
Takahashi, T.; Tamai, A.; Saito, H.
Nippon Ganka Gakkai Zasshi 92(10): 1696-1704
1988
ISSN/ISBN: 0029-0203 PMID: 3213774 Document Number: 323887
We recorded the spontaneous, rhythmic potentials (SRPs) from 10 eyes of 10 urethane-anesthetized, adult rats using a glass microelectrode inserted into the vitreous cavity from the pars plana. The frequency ranges of the SRPs were 22-43 Hz, and their peak-to-peak intervals were constant in each rat. Simultaneously recorded, averaged SRPs and electroretinogram (ERG) responses revealed that changes of the intensity of the photic stimulation and background illumination had significant efect on the ERG responses, while they had little effect on the SRPs; the SRPs were suppressed and diminished transiently by the stimulus light, but they reappeared immediately following the descending part of the b-wave with a constant latency after the photic stimulation, if the stimulus intensities were strong enough. The closer the tip of th recording electrode approached the surface of the retina, the more clearly the SRPs were recorded. Moreover, the SRPs diminished transiently with intravitreal injection of 0.5% lidocaine hydrochloride. These results suggest that a "dyad or reciprocal synapase" involving the gangion cells in the inner plexiform layer is involved in the generation of the SRPs in the rat retina.