Dissociated Muller (glial) cells from the neotenous tiger salamander retina respond electrogenically and rheogenically to three putative catecholamine (CA) neurotransmitters, epinephrine, norepinephrine and dopamine. All 3 CAs stimulate a net inward current and an increase in input resistance (Rn). The Muller cell response to the CAs is concentration dependent. At high concentrations ascorbate, an antioxidant used to protect the CAs from oxidation, stimulated a net outward current and a decrease in Rn. When the effects of ascorbate were considered, the CA response at 1 mM was no larger than the response at 100 μM, indicating that 100 μM CA maximally stimulated the Muller cell response.
- Muller cell
- Whole-cell recording