Photic stimulation of the suprachiasmatic nucleus via the non-visual optic system. A gene expression study in the blind Crx-/- mouse
| Autor: | Morten Møller, Louise Rovsing |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Melanopsin
Histology genetic structures Photic Stimulation Nerve Tissue Proteins Biology Blindness Retinal ganglion Pathology and Forensic Medicine Mice medicine Zeitgeber Animals Homeodomain Proteins Mice Knockout Neurons Retina Suprachiasmatic nucleus Cell Biology eye diseases medicine.anatomical_structure Gene Expression Regulation Hypothalamus Trans-Activators Suprachiasmatic Nucleus sense organs Neuroscience Retinohypothalamic tract |
| Zdroj: | Cell and tissue research. 358(1) |
| ISSN: | 1432-0878 |
| Popis: | The visual system of vertebrates consists of an image-forming and a non-image-forming optic system; the image-forming optic system involves the classic photoreceptors, the rods and cones, whereas the non-image-forming optic system involves the melanopsin-containing retinal ganglion cells. Both optic systems make direct neuroanatomical connections to the suprachiasmatic nucleus (SCN) in the hypothalamus in which the biological clock of vertebrates is located. The rhythmic output from SCN neurons is entrained by light via the retina and the retinohypothalamic tract. The response of exposure to light during the subjective night is an immediate expression of several early response genes in the SCN. We show, by quantitative real-time polymerase chain reaction, that the amount of melanopsin mRNA in the retinal ganglion cells is preserved in the blind Crx(-/-) mouse with degenerated classic photoreceptors. At zeitgeber time 16, the Crx(-/-) and wild-type mice were exposed to 1 h of light. This resulted in a strong up-regulation of the immediate early genes Nr4a1, Erg, and Rrad in the SCN of both genotypes. Light stimulation during the subjective night resulted in a strong up-regulation of c-fos in both genotypes with a significantly higher up-regulation in the blind Crx(-/-) mouse. Expression of Grp and Vip, the genes for two classic peptides located in the SCN, was not influenced by light stimulation. The data strongly indicate the involvement of the melanopsin-based non-visual optic system in the regulation of immediate early genes in the SCN. |
| Databáze: | OpenAIRE |
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