Photoreceptors ganglion cells

In addition to its presence in the RPE, ABCA1 has been found to be localized in the neural retina, particularly in the ganglion cell layer and rod photoreceptor inner segments (Tserentsoodol et al., 2006a), suggesting it may be involved in carotenoid transport throughout the retina. 

Figure 14.1 Schematic diagram of the blood-retinal barrier (BRB). The retinal cell layers seen histologically consist of retinal pigment epithelium (RPE) photoreceptor outer segments (POS) outer limiting membrane (OLM) outer nuclear layer (ONL) outer plexiform layer (OPL) inner nuclear layer (INL) inner plexiform layer (IPL) ganglion cell layer (GCL) nerve fiber layer (NFL) inner limiting membrane (ILM).

The Na" channel has a receptor site for cyclic GMP when cyclic GMP is bound, the channel is closed. This leads to a decrease in the intracellular Na ion concentration, resulting in hyperpolarisation of the cell membrane. This decreases the release of the neurotransmitter glutamate into the synapse that connects the photoreceptor cell to the bipolar neurones. In this specific case, a decrease in the neurotransmitter concentration in the synapse is a signal that results in depolarisation of the bipolar cell. The action potential in the bipolar cells communicate with ganglion cells, the axons of which form the optic nerve. Thus action potentials are generated in the axons which are... 

Weit A large number of ganglion cells in the retina are probably clock cells and have cryptochrome on that basis alone. Again, it is this issue of how to distinguish a photoreceptor role from a clock role. 

Poster Whether or not Pos induction is a marker of a photoreceptor or not is an open question. It is a marker of a depolarized ganglion cell. 

The retina extends forward to the sclera as a globe-shaped wineglass almost external to the skull. That part of the sclera devoid of retina is the pars planar, which is used as an access point for injection or for close delivery to the iris and ciliary body (ICB). When stripped from its basement membrane and opened out, the collapsed retina is a circular disk approximately 42 mm in diameter and 0.5 mm in thickness. The organization of the retina is based on a three-neuron chain (photoreceptor cell-bipolar cell-ganglion cell) and accompanying cells (horizontal, amacrine, and Muller cells)... 

Glutamate is the major excitatory neurotransmitter in the retina where it is released by photoreceptors, bipolar, and ganglion cells (Yang, 2004). 

In the rodent brain, D4 mRNA has a relatively restricted pattern of expression, being localized in the frontal cortex, in the olfactory bulb, hypothalamus and thalamus in the retina, D4 mRNA is expressed in the photoreceptor cell layer and in the inner nuclear and ganglion cell layers (Cohen et al., 1992 O Malley et al., 1992). 

Keywords Amacrine cell Bipolar cell Cone Fovea Horizontal cell Muller cells Photoreceptor Retina Retinal ganglion cell Rod... 

Figure 11.2. The five major retinal cell types (photoreceptors, bipolai cells, horizontal cells, amacrine cells, and ganglion cells) and tlieir synaptic connections.

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