The origins of the a- and b-wave of the @entity69868 were studied using simultaneous recordings made across the receptor layer and the full thickness of a piece of isolated albino @entity35 retina. An inwardly directed current flowing across the rod outer segments was eliminated from the recording when postsynaptic activity was blocked with @entity1953 or when current source density measurements were made along the length of the outer segments. Rod photovoltages were inferred by removing extraneous field potentials from the recordings made across the photoreceptor layer. The spatial properties of the photovoltage indicates the responses came from an area about 100 microm in diameter. The @entity2227 analog. APB, which blocks depolarizing bipolar cells, eliminated the b-wave but left the a-wave unaffected. The @entity69868 component due to depolarizing bipolar cells was inferred by subtracting recordings obtained before and after APB. After treatment with APB a slow component remained. This component was completely blocked by barium (200 microM), which blocks @entity972 channels on M  ller cells. Barium had virtually no effect on low-intensity photovoltages but did affect the amplitude and shape of the saturated responses. Barium increased the amplitude of the component of the @entity69868 which underlies the b-wave. It was concluded that the depolarizing bipolar cells directly generate the b-wave of the @entity69868 .

A dissection of the electroretinogram from the isolated XXXX retina with microelectrodes and drugs.

@entity2227 :: ('CHEBI:29987', 'Chemical') :: ['glutamate'] @entity69868 :: ('170909(Tax:10116)', 'Gene') :: ['ERG'] @entity972 :: ('MESH:D011188', 'Chemical') :: ['potassium'] @entity35 :: ('10116', 'Species') :: ['rat'] @entity1953 :: ('MESH:D003035', 'Chemical') :: ['cobalt']
@entity35 :: (10116,Species) :: ['rat']
