Nomeclature regarding AAV constructs

Q:  "On UNC vector core website (and DREADD wiki pages), I found two types, AAV2/5/8-CAMIIKa-HA-HM3Dq-IRES-mCitrine or AAV8-hsyn-HM3Dq-mCherry.

My question is, which one is better? and can I know the difference between them, in the aspect of expression level or anatomical specificity?

A:  The nomneclature gives the answer:


This is available in three serotypes (AAV2, AAV5 and AAV8)=we recommend starting with AAV8 serotypes 

CAMKIIka=the promotor. In this case the promotor is selective for neurons which express CAMIIKa (e.g. glutamatergic neurons in general)

HA=Hemagluttinin tag


IRES=internal ribosome entry site

mCitrene=GFP variant which is quite bright and more resistant to photobleaching than GFP

hSyn=human synapsin promotor which in this case specifies neuronal expression

M3Dq-mCherry=Gq DREADD as mCherry fusion protein

Thus, both will express Gq DREADD in neurons but one will specify excitatory neurons.