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PubMed1985

Intracellular recording from single and double cone cells isolated from the fish retina (Tinca tinca).

Intracellular recording were obtained from isolated single and double cone cells of the tench retina. Photoresponses show features characteristic of other species and behave linearly with very dim illumination. The cells spectral sensitivity matches their pigment absorption spectrum measured by previous authors. The principal and accessory members of double cones show a maximal sensitivity peak at about 644 and 547 nm, respectively. In addition, each of the two action spectra shows a secondary inflection at the peak wavelength of the adjacent member, suggesting functional coupling between the two members of double cones.

Animals↗

PubMedDate not supplied

Appearance of cGMP-phosphodiesterase immunoreactivity parallels the morphological differentiation of photoreceptor outer segments in the rat retina.

We have investigated by immunofluorescence the appearance of immunoreactive guanosine 3'-5' cyclic monophosphate phosphodiesterase (cGMP-PDE) during the postnatal development of the retina of the pigmented rat. We show that a sudden increase in immunoreactivity takes place during postnatal day five (P5), when rod outer segments begin to form; immunoreactivity develops rapidly in the following days. Labeling is restricted to the developing photoreceptor outer segments, sparing other retinal cells, as confirmed by electron microscopy immunocytochemistry. In addition, cGMP-PDE immunoreactivity follows a center-to-periphery gradient paralleling photoreceptor differentiation. It appears that cGMP-PDE is expressed when the photoreceptor subcellular compartments are already formed, and represents a specific marker of late photoreceptor differentiation. The appearance of cGMP-PDE during development is temporally correlated with the appearance of other proteins of the phototransduction machinery.

3',5'-Cyclic-GMP Phosphodiesterases↗