Background
Mounting evidence suggests that neuronal voltage-gated CaV1.2 and CaV1.3 L-type calcium channels (LTCCs) can modulate mood and anxiety behaviors. In CaV1.2 dihydropyridine (DHP)-insensitive mice (CaV1.2DHP-/- mice), systemic application of the DHP channel activator BAYK 8644 induced pro-depression-like behavior providing evidence for a possible role of CaV1.3 channels in mood behavior. We therefore explored the role of CaV1.3 LTCCs in depression- and anxiety-like behaviors using CaV1.3-deficient mice (CaV1.3-/-). However, CaV1.3-/- mice are congenitally deaf and it is so far unclear how deafness affects emotional behavior in mice. We therefore used another mouse model suffering from congenital deafness, claudin 14-deficient mice (Cldn14-/-) as a control to address this question. As CaV1.3 channels are expressed in the retina we also investigated CaV1.3-/- mice for possible disturbances in retinal morphology and visual function that could interfere with behavioral analysis.