New Articles by Hiramoto and Colleagues

These are a couple of the newer articles [Hiramoto et al., 2009: (http://www.ncbi.nlm.nih.gov/pubmed/19184072); Hiramoto, 2009: (http://www.ncbi.nlm.nih.gov/pubmed/19500182)] on the effects of ultraviolet radiation (UVR) on trigeminal ganglion neurons, etc. I just came across these today and haven't had a chance to look through them in detail. The one showing that optic nerve denervation blocks the effect of UVA is probably not actually showing that, and it may be that the fibers of ciliary ganglion neurons are being severed. There are articles discussing the difficulty in sparing or even seeing parts of the ciliary ganglia during operations in humans. There's no transmittance of UVA or UVB past the lens and iris. Well, I guess 1-2 percent in the UVA wavelengths can reach part of the vitreous humor [Sliney, 1997: (http://cat.inist.fr/?aModele=afficheN&cpsidt=2855724)], but there's no way that amount could reach the retina and produce biological effects, in my opinion. The articles showing immediate-early gene expression in parts of the retina, following UVR, are showing a polysynaptic effect of some kind, in my opinion, and I don't think there could be a "coherent" effect of something that could, by some fluke, reach those cells by diffusion from cells in the anterior chamber, etc. Another thing is that some ciliary ganglion neurons actually do innervate the corneas in rodents, and that may well account for the past research showing that ciliary ganglionectomy could antagonize the effects of UVR exposure. But the effects on the trigeminal ganglion neurons are likely to predominate, in my view.