Differentiation of short-wavelength-sensitive cones by NADPH diaphorase histochemistry.

AUTOR(ES)

Petry, H M

RESUMO

NADPH diaphorase (NADPH dehydrogenase; EC 1.6.99.1) histochemistry labels neurons that synthesize the neurotransmitter nitric oxide (NO). In retina, it has been demonstrated that NO can affect the metabolism of cGMP in rod photoreceptors. To investigate potential involvement of NO in cone photoreceptor activity, we utilized NADPH diaphorase histochemistry to study the cone-dominated retina of the tree shrew (Tupaia belangeri). Unexpectedly, our results revealed different NADPH diaphorase activity in the cellular subcompartments of the spectral classes of cone photoreceptors. Although all cones showed intense labeling of inner segment ellipsoids, the short-wavelength-sensitive (SWS or "blue-sensitive") cones and the rods displayed intense staining of the myoid inner segment subcompartment as well. Furthermore, only SWS cones and rods displayed surface labeling of their nuclei. These findings indicate a manner in which SWS cones differ biochemically from other cone types and in which they are more similar to rods. Such differences may underlie some of the unusual functional properties of the SWS cone system, which have been attributed to postreceptoral processes.

Documentos Relacionados

• Histochemistry. Theoretical and Applied
• Human photopic vision with only short wavelength cones: post-receptoral properties.
• Features of the aperiodic microfibrils associated with mouse dental basement membrane demonstrated by ultrastructural histochemistry.
• Pseudoexfoliative disease of the lens: a study in electron microscopy and histochemistry.
• Molecular and cellular responses of islets during perturbations of glucose homeostasis determined by in situ hybridization histochemistry.