Undersized Dendritic Arborizations in Retinal Ganglion Cells of the rd1 Mutant Mouse: A Paradigm of Early Onset Photoreceptor Degeneration

This paper by Devid Damiani, Elena Novelli, Francesca Mazzoni and Enrica Strettoi documents continued negative plasticity in retina by examining ganglion cells in the rd1 mouse.  The rd1 mouse is one of many models of retinal degenerative disease, in this case as an autosomal recessive retinal degenerative disease.  This work gets at the remodeling issue in retinal degenerative diseaseby examining the last cells in the chain of retinal cells that process information before sending it out to the brain and other CNS centers for further processing.   Continue reading “Undersized Dendritic Arborizations in Retinal Ganglion Cells of the rd1 Mutant Mouse: A Paradigm of Early Onset Photoreceptor Degeneration”

Age-Related Changes In The Daily Rhythm of Photoreceptor Functioning And Circuitry In A Melatonin-Proficient Mouse Strain

This is an interesting study in PLoS One examining the involvement of melatonin in the retina, particularly in the survival of retinal neurons through aging studies in CH3-f+/+ mice, a melatonin proficient mouse strain.  As expected, certain physiological measures (a and b waves) are lost during aging, and in particular, the daily circadian rhythms of those measures.  However, the authors, Kenkichi Baba, Francesca Mazzoni, Sharon Owino, Susana Contreras-Alcantara, Enrica Strettoi and Gianluca Tosini did something really interesting and added exogenous melatonin to their assay and concluded that responsiveness of exogenous melatonin is also reduced during aging.

Notable Paper: Localization of Melatonin Receptor 1 in Mouse Retina and Its Role in the Circadian Regulation of the Electroretinogram and Dopamine Levels

I’ve watched the development of the circadian rhythm research starting with Joe Takahashi‘s work discovering CLOCK in the mammalian SCN back in 1994.  Since then there has been an explosion of circadian rhythm biology work including an I suppose, unsurprising amount of research in the retina proper.

This paper by Anamika Sengupta, Kenkichi Baba, Francesca Mazzoni, Nikita V. Pozdeyev, Enrica StrettoiP. Michael Iuvone, and Gianluca Tosini describes the localization of type 1 melatonin receptors in the mouse retina that has interesting potential implications for additional circadian mechanisms in the retina.

Continue reading “Notable Paper: Localization of Melatonin Receptor 1 in Mouse Retina and Its Role in the Circadian Regulation of the Electroretinogram and Dopamine Levels”