Types of bipolar cells in the mouse retina

Abstract

We studied the morphology of bipolar cells in fixed vertical tissue sections (slices) of the mouse retina by injecting the cells with Lucifer Yellow and Neurobiotin. Nine different cone bipolar cell types and one rod bipolar cell type were distinguished. The major criteria for classifying the cells were the branching pattern and stratification level of their axon terminals in the inner plexiform layer (IPL). To assess this, the IPL was subdivided into five strata of equal width. The slices were immunostained for calretinin, which labels three horizontal bands serving as a standard measure for the precise localization of the axon terminals. Immunostaining the retina with antibodies against the G-protein Ggamma13, a marker for ON-bipolar cells, made it possible to separate OFF- and ON-bipolar cells. At least two OFF-cone bipolar cells (Types 1 and 2) were immunolabeled with antibodies against the neurokinin 3 receptors (NK3R). A further OFF- and an ON-cone bipolar cell (Types 3 and 5) were immunostained with antibodies against the calcium-binding protein CaB5. The bipolar cell types described here were compared with previous schemes of rat and primate bipolar cells. Homologous types between the three species are discussed.

Two types of cone bipolar cells express voltage-gated Na+ channels in the rat retina

“…These CBCs, referred to as CB2 in this study, should undoubtedly correspond to type 3 CBCs that have been described both in rats (Euler & Wässle, 1995;Hartveit, 1997) and in mice (Ghosh et al, 2004;Pignatelli & Strettoi, 2004;Ivanova & Müller, 2006).…”

“…The existence of two subclasses of type 5 CBCs has recently been reported in the rat based on the differential immunohistochemical staining of HCN channels (Fyk-Kolodziej & Pourcho, 2007). In the mouse, morphological variability in type 5 CBCs has also been previously reported (Ghosh et al, 2004), suggesting the possibility of existing multiple subclasses of type 5 CBCs in the mouse. The results of this study, however, provide the first physiological evidence for the existence of two subclasses of type 5 CBCs in the rat, one of which expresses voltage-gated Na + channels.…”

Behavioural and physiological limits to vision in mammals

“…Further insights can be gained by comparing the processing of rod signals to that of cone signals. Cone signals immediately diverge to approximately 10 bipolar cell types [54][55][56][57][58]. This divergence establishes the parallel processing of visual information, a strategy that is carried forth throughout the brain.…”

Stratification of alpha ganglion cells and ON/OFF directionally selective ganglion cells in the rabbit retina

“…Haverkamp et al (2003) suggested that the primate IPL is thick enough to accommodate 20 sublayers. The number of cone bipolar cell types in the mammalian retina is usually given between 10 and 12, plus one for the rod bipolar cells (Haverkamp et al, 2003;Ghosh et al, 2004;MacNeil et al, 2004), and there is strong evidence that different bipolar cell types have different physiological properties, thus splitting the photoreceptor signals into different channels (DeVries, 2000). The number of ganglion cell types has been estimated as 13 or 14, but there is usually an unclassified remainder which could include a number of sparse or low-density cell types (Rockhill et al, 2002;Marc & Jones, 2002;Dacey et al, 2003;Yamada et al, 2005).…”

“…Each type branches at a characteristic depth in the IPL (Boycott & Wässle, 1991;Hartveit, 1997;Haverkamp et al, 2003;Ghosh et al, 2004;MacNeil et al, 2004) while the rod bipolar cells terminate in sublamina 5 (Young & Vaney, 1991;Massey & Mills, 1999). The division of the IPL is functional such that OFF bipolar cells terminate in the upper half, sublamina a, while ON bipolar cells, including the rod bipolar cell, terminate in sublamina b. Ganglion cells also obey these stratification rules so that OFF ganglion cells branch in sublamina a, ON ganglion cells branch in sublamina b, and ON/OFF ganglion cells are bistratified with branches in both a and b (Famiglietti & Kolb, 1976;Bloomfield & Miller, 1986;Amthor et al, 1989a,b).…”