Tyrosine-Hydroxylase-Immunoreactive Neurons in Retinal Transplants in the Rat

Abstract

Embryonic rat retinae were transplanted to the brains of newborn rats, and the distribution of catecholaminergic neurons in the retinal tissue was studied 1–2 months after transplantation, using the tyrosine hydroxylase (TH) immunohistochemical method. The results showed that distinct TH-positive cells were identified in all retinal transplants examined. The somata of the majority of these TH-immunoreactive cells were located along the inner margin of the inner nuclear layer in the retinal transplants; the processes of these cells were distributed mainly in the outer portion of the inner plexiform layer. This pattern is comparable to that observed in retinae of normal and host rats, suggesting that the organization of the catecholaminergic neurons in the transplant is largely similar to that in the normal retina. However, a reduction of the immunoreactivity in the plexiform layers and subpopulations of TH-positive cells with somatic diameter smaller than 8 µm or larger than 18 µm was observed in most of the retinal transplants studied. This implies that the organization of the catecholaminergic system in the transplant may not be as intact as in the normal retina.

Acute and chronic effects of intravitreally injected β-amyloid on the neurotransmitter system in the retina

“…Both injected and un-injected eyes were dissected out, the cornea and lens removed, and then immersed in the same fixative overnight before they were processed for frozen sectioning at 20 μm thickness. Serial alternate sections collected were processed for immmunohistochemistry, as described elsewhere (Guo et al, 1990, 1991, 1992, Bresciani et al, 2002; Jen et al, 1998; Walsh et al, 2002, 2005; Yang et al, 1992). In brief, alternate sections were incubated in a solution containing monoclonal or polyclonal antibodies for a number of glial or neuronal markers, including, ChAT ((1:20), Boehringer Manheim), GABA ((1:8000), Sigma, UK), glial fibrillary acidic protein (GFAP, 1:600, Sigma), tyrosine hydroxylase (TH, 1:1000, Sigma, UK), and tryptophan hydroxylase (TryptH, 1:1000, Sigma).…”

Differential effects of interleukin-1β and S100B on amyloid precursor protein in rat retinal neurons

“…This is a potentially useful model because retinal ganglion cells (RGC) constitutively express APP (Morin et al 1993) and the closed nature of the system means that the injected substances remain in situ rather than being rapidly cleared, giving them the opportunity to act locally. Furthermore, the retina contains most of the nerve cells that express AD-associated molecules, all the major neurotransmitter-producing neurons and most of the glial populations found in the brain (Guo et al 1991, 1992a, 1992b; Yang et al 1992; Chen et al 1996; Bresciani et al 2002; Walsh et al 2005; Watts et al 2007), thus enabling us to study the interplay of these cytokines within a central nervous system setting.…”