Microelectrode penetration of the wall of porcine retinal arterioles in vitro results in recordings from several cell types

• Published in: Acta ophthalmologica (Oxford, England) England), 2017-09, Vol.95 (S259), p.n/a
• Main Authors: Kudryavtseva, O., Aalkjaer, C., Bek, T.
• Format: Article
• Language: English
• Subjects: Arterioles; Depolarization; Immunoreactivity; Intracellular; Membrane potential; Microelectrodes; Polyvinyl chloride; Potassium chloride; Retina; Retinal cells; Smooth muscle
• ISSN: 1755-375X; 1755-3768
• DOI: 10.1111/j.1755-3768.2017.0F069

Purpose A novel population of perivascular cells (PVC) is located immediately external to the vascular smooth muscle cells of retinal arterioles, express immunoreactivity to the pericyte marker NG2 and give rise to processes that extend into the retina. This suggests that PVCs could play a role in neurovascular coupling. However, the anatomical basis for the connection of PVC processes to the surrounding retina has not been characterized in detail. The aim of the present study was to establish a method for electrophysiological characterization of cells in the perivascular retina for the study of neurovascular coupling. Methods First order porcine retinal arterioles with preserved perivascular retinal tissue were mounted in a wire myograph. A glass microelectrode (WPI, USA) with a tip resistance of 30 ‐ 100 MOhm filled with 3M KCl solution was inserted into cells in the perivascular retina using an electronic micromanipulator. The microelectrode was connected to an amplifier (Electrometer 773 Duo, WPI, USA) and the intracellular membrane potential was recorded at resting conditions and after addition of 40mM KCl or solvent. Results Recordings from thirty perivascular retinal cells from eight arterioles showed membrane potentials ranging from ‐100 to ‐40 mV (mean ‐68± 3 mV). The most frequent membrane potential was ‐80 mV (30% of the cells). 40mM KCl produced a significant depolarization of the cells of 13 ± 3 mV (p=0.03, n=10), whereas solvent induced no significant change in the membrane potential (p=0.6, n=10). Conclusions Cells in the retinal arteriolar wall can be penetrated with microelectrodes for measurement of the membrane potential. The recordings suggest the existence of multiple cell types with distinct membrane potentials. The anatomical basis for these different cell types should be characterized further by intracellular dye injection.