Generation of a mouse line expressing Cre recombinase in glycinergic interneurons.

In caudal regions of the CNS, glycine constitutes the major inhibitory neurotransmitter. Here, we describe a mouse line that expresses Cre recombinase under the control of a BAC transgenic glycine transporter 2 (GlyT2) promoter fragment. Mating of GlyT2-Cre mice with the Cre reporter mouse lines Rosa26/LacZ and Rosa26/YFP and analysis of double transgenic offsprings revealed strong transgene activity in caudal regions of the central nervous system, i.e., brain stem and spinal cord. Some additional Cre expression was observed in cortical and cerebellar regions. In brain stem and spinal cord, Cre expressing cells were identified as glycinergic interneurons by staining with GlyT2- and glycine-immunoreactive antibodies; here, >80% of the glycine-immunoreactive cells expressed the Cre reporter protein. These data indicate that GlyT2-Cre mice are a useful tool for the genetic manipulation of glycinergic interneurons.