The Rothlab (http://pdsp.med.unc.edu/rothlab/) has received feedback from users regarding various DIO DREADD-based IRES constructs (e.g. DIO-hSyn-DREADD-IRES-YFP). Our sense is that because of the large size of the insert, AAV-based packaging is suboptimal leading to low transduction efficiency.
Accordingly we are no longer offering AAV viral stocks of these vectors.
If users wish to obtain the cDNAs they will soon be available via addgene: