GABAc feedback pathway modulates the amplitude and kinetics of ERG b-wave in a mammalian retina in vivo.
The electroretinogram b-wave is generally believed to reflect mainly light-induced activity of ON-center bipolar cells and Muller cells. Recently, there is increasing evidence that third-order retinal neurons can also contribute significantly to the b-wave. In a previous study (Vis. Res. 40 (2000) 579) we proposed that the GABAc feedback from amacrine cells to bipolar cells can affect both the amplitude and kinetics of the b-wave. Here we show that blocking this feedback has profound effects on b-wave amplitude and kinetics. These results demonstrate that feedback to bipolar cells is an important mechanism through which amacrine cells contribute to b-wave generation. Our results also provide functional evidence that the feedback may be involved in temporal processing in the mammalian retina.
Dong
Cun-Jian
CJ
Department of Biological Sciences, Allergan Pharmaceuticals, RD-2C Allergan Inc., 2525 Dupont Drive, Irvine, CA 92612, USA. dong_james@allergan.com
Hare
William A
WA
D025042:Amacrine Cells / Q000502:physiology; D000818:Animals; D004596:Electroretinography / Q000187:drug effects; D025461:Feedback, Physiological / Q000502:physiology; D018756:GABA Antagonists / Q000494:pharmacology; D011817:Rabbits; D018079:Receptors, GABA / Q000502:physiology*; D012160:Retina / Q000502:physiology*
D018756:GABA Antagonists; C087200:GABA-C receptor; D018079:Receptors, GABA