RESUMO
The stimulated expression of the c-fos gene was used in this study to characterize the residual vision of retinal degeneration (rd) mice. Conventional immunohistochemistry was employed to detect Fos-positive nuclei in the rd mouse retina and brain after monocular application of static and dynamic photic stimuli. Diffuse light induced Fos-positive nuclei in the inner nuclear and ganglion cell layers of the stimulated retina and in the contralateral pretectal olivary nucleus. On the other hand, Fos-positive nuclei were rarely detected in the rd mouse retina and brain after stimulation with a slowly displaced random-dot pattern. These results suggest that the residual vision of the rd mouse involves mainly the circuits that are related to the processing of static photic stimuli.
Assuntos
Encéfalo/metabolismo , Genes fos , Estimulação Luminosa/métodos , Retina/metabolismo , Degeneração Retiniana/metabolismo , Vias Visuais/fisiopatologia , Animais , Encéfalo/fisiopatologia , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Núcleo Olivar/metabolismo , Retina/fisiopatologia , Degeneração Retiniana/genética , Degeneração Retiniana/fisiopatologia , Células Ganglionares da Retina/metabolismo , Vias Visuais/metabolismoRESUMO
The effect of neural lesions upon the distribution of a neuronal nicotinic acetylcholine receptor subunit was investigated in the chick nervous system. Following unilateral retinal lesions, the neuropil staining with an antibody against the Beta2 receptor subunit was dramatically reduced or completely eliminated in all retinorecipient structures. Lesions of the lateral spiriform nucleus, a major Beta2 subunit-containing mesencephalic nucleus, produced a marked reduction of neuropil staining in the deeper layers of the tectum, which represent the main target of that nucleus. The present results indicate that the Beta2 subunit is transported in axonal systems, and might therefore constitute presynaptic receptors in some brain areas.