Cannabinoid receptor type 1 expression during postnatal development of the rat retina

Abstract

Cannabinoid receptor type 1 (CB1R) participates in developmental processes in the central nervous system (CNS). The rodent retina represents an interesting and valuable model for studying CNS development, because it contains well-identified cell types with clearly established and distinct developmental timelines. Very little is known about the distribution or function of CB1R in the developing retina. In this study, we investigated the expression pattern of CB1R in the rat retina during all stages of postnatal development. Western blots were performed on retinal tissue at different time points between P1 and adulthood. In order to identify the cells expressing the receptor and the age at which this expression started, immunohistochemical co-staining was carried out for CB1R and markers of the different cell types comprising the retina. CB1R was already present at P1 in various cell types, i.e., ganglion, amacrine, horizontal, and mitotic cells. In the course of development, it appeared in cone photoreceptors and bipolar cells. For some cell types (bipolar, Müller, and some amacrine cells), CB1R was transiently expressed, suggesting a potential role of this receptor in developmental processes, such as migration, morphological changes, sub-identity acquisition, and patterned retinal spontaneous activity. Our results also indicated that CB1R is largely expressed in the adult retina (cone photoreceptors and horizontal, most amacrine, and retinal ganglion cells), and may therefore contribute to retinal functions. Overall these results indicate that, as shown in other structures of the brain, CB1R could play an instrumental role in the development and function of the retina.

The Endocannabinoid System in the Vervet Monkey Retina

“…These results summarize results published in several articles [43,49,50,[55][56][57]. OS, photoreceptor outer segments; IS, photoreceptor inner segments; ONL, outer nuclear layer; ONL, outer plexiform layer; INL, inner nuclear layer; IPL, inner plexiform layer; GCL, ganglion cell layer.…”

Chemoarchitecture of glial fibrillary acidic protein (GFAP) and glutamine synthetase in the rat optic nerve: An immunohistochemical study

“…The staining obtained with the two antibodies in the rat was similar to that previously reported in the mouse 6,27,30) and rat 11,31) .…”

Cannabinoid receptor agonists modulate calcium channels in rat retinal müller cells

“…Firstly, although cannabinoid receptor mRNAs and proteins are expressed in rat Mu¨ller cells (Buckley et al, 1998;Porcella et al, 1998) (Fig. 7), the density of the receptors is lower in adult animals (Zabouri et al, 2011). It seems likely that the effects by activation of these receptors could not be detected.…”

“…By activating the specific cannabinoid receptors, mainly the CB1 receptor (CB1R), eCBs, such as anandamide (AEA) and 2-arachi donoylglycerol (2-AG), and CB1R agonist WIN55212-2 modulate the voltage-gated K + and Ca 2+ channels in a variety of retinal neurons (Straiker et al, 1999a;Yazulla et al, 2000;Fan and Yazulla, 2003;Straiker and Sullivan, 2003;Lalonde et al, 2006). In regard to Mu¨ller cells, it is reported that CB1Rs are expressed in the cells of goldfish (Yazulla et al, 2000) and Long-Evans rats (Zabouri et al, 2011). However, it has not been clearly established whether cannabinoid agonists may modulate the Ca 2+ channels of Mu¨ller cells.…”

“…These results suggest that elevation of [Ca 2+ ] i may be involved in the induction of Mu¨ller cell gliosis under pathological conditions. Endocannabinoid (eCB) system, extensively distributed in the vertebrate retina, regulates the multiple retinal neuronal functions and participates in visual information processing (Straiker et al, 1999a,b;Yazulla et al, 1999Yazulla et al, , 2000Straiker and Sullivan, 2003;Yazulla, 2008;Zabouri et al, 2011). By activating the specific cannabinoid receptors, mainly the CB1 receptor (CB1R), eCBs, such as anandamide (AEA) and 2-arachi donoylglycerol (2-AG), and CB1R agonist WIN55212-2 modulate the voltage-gated K + and Ca 2+ channels in a variety of retinal neurons (Straiker et al, 1999a;Yazulla et al, 2000;Fan and Yazulla, 2003;Straiker and Sullivan, 2003;Lalonde et al, 2006).…”