Bipolar Cell Type 2 (BC2) are one of five OFF bipolar cells in the retina. They stratify in the OFF sublamina in the inner plexiform layer (IPL). BC2s are in contact with at least one or two cone pedicles, and They can be distinguished from other bipolar cells with their expression of recoverin and a type II cadherin, cdh8 (Havercamp et al., 2003, Duan et al., 2014).
There are several markers and transgenes that can be used to label BC2s, although not all of them are selective. Both BC1s and BC2s are immunoreactive for Neurokinin-3 receptor (NK3R) (Havercamp et al., 2003). Bipolar cells in sublamina 1 and 2 of the IPL express a synaptic vesicle associated protein called synaptotagmin 2 (Syt 2), including BC2s (Fox and Sanes, 2007, Wassle et al., 2009). Recoverin, a neuronal calcium binding protein, is selectively expressed by BC2s (Havercamp et al., 2003). Recently, it was found that a type II cadherin, cdh8, is also selectively expressed in BC2s (Duan et al., 2014). The transgenic mouse, Clm12, one of the mouse lines that express Clomeleon under the control of the thy-1 promoter, is known to label BC2s and BC6s (Wassle et al., 2009).