Differential effects of charybdotoxin on the activity of retinal ganglion cells in the dark- and light-adapted mouse retina.
Patch-clamp recordings were made from retinal ganglion cells in the mouse retina. Under dark adaptation, blockage of BK(Ca) channels increases the spontaneous excitatory postsynaptic currents (EPSCs) and light-evoked On-EPSCs, while it decreases the light-evoked Off inhibitory postsynaptic currents (IPSCs). However, under light adaptation it decreases the light-evoked On-EPSCs, the spontaneous IPSCs and the light-evoked On- and Off-IPSCs. Blockage of BK(Ca) channels significantly altered the outputs of RGCs by changing their light-evoked responses into a bursting pattern and increasing the light-evoked depolarization of the membrane potentials, while it did not significantly change the peak firing rates of light-evoked responses.
Nemargut
Joseph P
JP
Department of Structural and Cellular Biology, School of Medicine, Tulane University, New Orleans, LA 70112, USA.
Zhu
Junling
J
Savoie
Brian T
BT
Wang
Guo-Yong
GY
D000221:Adaptation, Ocular / Q000502:physiology*; D000818:Animals; D018999:Charybdotoxin / Q000494:pharmacology*; D003623:Dark Adaptation / Q000502:physiology; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018408:Patch-Clamp Techniques; D010775:Photic Stimulation / Q000379:methods; D026902:Potassium Channel Blockers / Q000494:pharmacology*; D012165:Retinal Ganglion Cells / Q000187:drug effects* / Q000502:physiology; D055366:Synaptic Potentials / Q000187:drug effects
C530995:BKCa protein, mouse; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; D026902:Potassium Channel Blockers; D018999:Charybdotoxin