Xylazine promotes axonal regeneration in the crushed optic nerve of adult rats

Abstract

Xylazine, an alpha-2 adrenergic agonist, activates the endogenous trophic factors and neuronal survival signaling. Here, we tested the regenerative effect of xylazine on damaged optic nerve axons in adult rats. After optic nerve crush, xylazine was intraperitoneally injected into three groups of rats: a single administration immediately after the crush, intermittent administration, and daily administration. On day 14, the regenerated axons were quantitatively evaluated by anterograde labeling. Everyday administration but neither single nor intermittent administration markedly increased the number of labeled axons beyond the crush site, with upregulation of growth-associated protein-43 in the ganglion cell layer and the regenerated axons. It was concluded that xylazine promotes axonal regeneration in damaged optic nerves of adult rats.

Axonal regeneration induced by repetitive electrical stimulation of crushed optic nerve in adult rats

“…The left ON was then exposed and crushed 2 mm behind the globe with jewelry forceps (Dumont #545, World Precision Instruments, Sarasota, FL, USA) for 10 s, as described previously. 15 Direct ophthalmoloscopy verifi ed that the retinal blood fl ow was not damaged.…”

“…CTB immunostaining was then performed as described. 15 After blocking, the sections were incubated in a solution of goat anti-CTB antibody (List Biological Laboratories) overnight at 4°C. After washing in PBS, the sections were incubated with a biotinylated rabbit anti-goat IgG antibody (Vector Laboratories, Burlingame, CA, USA) for 2 h at room temperature, followed by 1 : 400 Alexa 488-conjugated streptavidin (Molecular Probes, Eugene, OR, USA).…”

“…On day 12 after the ON crush, cholera toxin B subunit [CTB, 2.5 μg/μl in 2 μl phosphate-buffered saline (PBS); List Biological Laboratories, Campbell, CA, USA] was injected into the vitreous body to anterogradely label the RGC axons as described. 15 Two days after CTB application, the animals were transcardially perfused with 4% paraformaldehyde (PFA) in 0.1 M phosphate buffer (PB) and 16-μm-thick longitudinal cryosections of the ON were made. CTB immunostaining was then performed as described.…”

Tafluprost protects rat retinal ganglion cells from apoptosis in vitro and in vivo

“…After the left optic nerve sheath was exposed, the entire nerve was mechanically crushed 2 mm behind the eye with jewelry forceps (Dumont no. 545, World Precision Instruments, Tokyo, Japan) for 10 seconds as described previously [12], although the tip of the forceps was not seen. Normal retinal circulation was confirmed by ophthalmoscope.…”

P7C3 Suppresses Neuroinflammation and Protects Retinal Ganglion Cells of Rats from Optic Nerve Crush

“…The superior rectus muscle was incised to expose the left optic nerve, and the left optic nerve was crushed 2 mm behind the eye with forceps for 10 seconds. 18 Care was taken not to occlude the blood vessels and cause retinal ischemia. We confirmed that the retinal circulation was not blocked by indirect ophthalmoscopy and also verified this by demonstrating that the HIF-1a gene was not upregulated by real-time PCR.…”