Progress in FY2015 includes the following: In order to study the specific cells, sites, tissues, and transmitters by which BRS-3 acts, we have generated floxed Brs3 mouse. The floxed mice allow determination of necessity of Brs3 in the particular cells. We are in the process of using this mouse by breeding with germline cre-expressing mice and by injection of cre-expressing virus into specific brain nuclei. These allow knockout of Brs3 in cells defined by their cre expression pattern or by location within the brain. Similarly, we have generated loxTB-Brs3 mice. The loxTB-Brs3 mice allow determination of sufficiency of Brs3 in the particular cells. We have achieved germline transmission and are expanding the line and in the process of proving that the mice have the expected characteristics. These mice allow expression of Brs3 only in cells defined by their cre expression pattern and by location within the brain. Finally we have generated Brs3-T2A-CreERT2 mice, in which cre is expressed as a fusion mRNA with the endogenous Brs3 mRNA, leading to cre protein expression expected to be at similar level as Brs3. We have now shown that these mice do express cre in a tamoxifen-dependent manner and in the reported distribution pattern of Brs3. We are expanding the line.