Is a neuronal chain between the pineal body and the retina in rats and hamsters? Transneural tracing studies.

Neuronal chains between the retina and the pineal body were investigated. Transneuronal tracers, retrograde spreading pseudorabies virus (labeled with green fluorescent protein, memGreen-RV) and virus spreading in both ante- and retrograde directions (labeled with red fluorescent protein, Ka-VHS-mCherry-A-RV) were injected into the right eye of vitreous body of intact or bilaterally sympathectomized Wistar male rats. Intact golden hamsters also received memGreen-RV into the eye and Ka-VHS-mCherry-A-RV into the pineal body.

Peripheral autonomic nerves of human pineal organ terminate on vessels, their supposed role in the periodic secretion of pineal melatonin.

Nonvisual pineal and retinal photoreceptors are synchronizing circadian and circannual periodicity to the environmental light periods in the function of various organs. Melatonin of the pineal organ is secreted at night and represents an important factor of this periodic regulation. Night illumination suppressing melatonin secretion may result in pathological events like breast and colorectal cancer.

Visual pigment coexpression in all cones of two rodents, the Siberian hamster, and the pouched mouse.

Purpose: To decide whether the identical topography of short- and middle-wavelength cone photoreceptors in two species of rodents reflects the presence of both opsins in all cone cells.

Methods: Double-label immunocytochemistry using antibodies directed against short-wavelength (S)-and middle- to long-wavelength (M/L)-sensitive opsin were used to determine the presence of visual pigments in cones of two species of rodents, the Siberian hamster (Phodopus sungorus) and the pouched mouse (Saccostomus campestris) from South Africa. Topographical distribution was determined from retinal whole-mounts, and the colocalization of visual pigments was examined using confocal laser scanning microscopy.