Dopaminergic and GABAergic retinal cell populations in mammals

Dopaminergic and GABAergic amacrine cells are direct targets of melatonin: Immunocytochemical study of mt1 melatonin receptor in guinea pig retina

“…3C. The type 2CA cells, characterized by a small cell body and weak TH immunoreactivity (Nguyen-Legros et al, 1997), were occasionally found to be mt 1 positive (Figs. 3C and 3D), but 60% of this cell type was negative for the mt 1 receptor (Table 1).…”

“…3A-3D, Table 1). The type 1CA cells, characterized by a large cell body and intense TH immunoreactivity (Nguyen-Legros et al, 1997), were always immunoreactive for the mt 1 receptor (Table 1). Although mt 1 immunoreactivity in this cell type was weak, it was diffusely distributed throughout the cell body as typically shown in Fig.…”

rho1 GABAC receptors are expressed in fibrous and cartilaginous layers of chick sclera and located on sclera fibroblasts and chondrocytes

“…As for the muscarinic system where the functional role of the non-neuronal receptors is unclear (McBrien et al 2009), the functional role of rho 1 GABA C receptors in sclera is similarly unexplored. In the retina the receptors are inhibitory and can regulate the release of neurotransmitters such as dopamine, melatonin (Kazula et al 1993;Nguyen-Legros et al 1997) and acetylcholine (Massey et al 1997;Chebib et al 2009); More is known on the function of other receptor types, for example melatonin receptors; melatonin receptors have been identified in the choroid and sclera of chicks (Wiechmann and Rada 2003) and these receptors may drive a mechanism by which melatonin more generally regulates ocular diurnal rhythms (Rada and Wiechmann 2006). Given there is some evidence of GABA C receptors involvement in (Arnaud et al 2001), and evidence for interactions between melatonin and GABA C receptors (Prada et al 2005) an untested possibility is these systems interact to control scleral physiologic oscillations (Nickla et al 1999).…”

Expression of the γ-Aminobutyric Acid (GABA) Plasma Membrane Transporter-1 in Monkey and Human Retina

“…In addition, the presence of GAT-1 was tested in two distinct subpopulations of GABAergic neurons, such as the VIP-and TH-immunoreactive amacrine cells. 62,63 Finally, because there are reports of GABA immunoreactivity in primate bipolar cells, 64 -69 double labeling with GAT-1 and Mab115A10 antibodies was performed to assess the possible expression of GAT-1 immunoreactivity by bipolar cells.…”