Hi not sure about HSV. But, AAV with channelorhodopsin or halorhodopsin is widely used now. You can get the virus from north carolina university.

http://genetherapy.unc.edu/services.htm

you may need to sign the material transfer agreement. If you are injecting in the wild type, you may infect all the neurons (using AAV- Camk11 -channelo or halo-YFP)as a promoter. With the cre specific EF1a promoter (example., THCre mice), you can selectively infect the dopaminergic neurons. I think depends on the area of interest and type of neurons you can select the construct.

Thanks Anton, I will look up the NCU virology lab. I'm using HSV because I'm trying induce the expression retrogradely. But AAV does look promising.

Hi, yes you are right. AAV used for anterograde expression. perhaps, some monosynaptic rabbit virus based retrograde virus is available which is known for its short life span (6 weeks) and traveling up to one synapse backward (used for anatomy). But, i am not sure weather it has channelorhodopsin

Laura, thank you for your input. My understanding is that CamKII are expressed in those areas that I mentioned. I am considering looking into AAVs next.

Thank you Jonas.

There are two recent papers (and counting) using a HSV variant (LT-HSV) with a longer expression window before the onset of toxicity; it's made at the MIT viral vector core by Rachel Neve:

http://www.ncbi.nlm.nih.gov/pubmed/23515158

http://www.ncbi.nlm.nih.gov/pubmed/24267654

Also see the following reviews for overviews of the different flavors of opsins and viral options:

http://www.ncbi.nlm.nih.gov/pubmed/22179551

http://www.ncbi.nlm.nih.gov/pubmed/21745635

Good luck!

Lief Fenno

These are all great answers. I have had good luck with AAVs produced by UNC Chapel Hill as well. I recently worked for 2 years at MIT and heard mixed stories about the success of the LT-HSVs from Rachel Neve...I think this will be very dependent on the experimental context but is certainly worth trying out. It is worth noting that Ian Wickersham is also now running a group at MIT (Genetic Neuroengineering Group) and has expertise in Rabies tracing among other cutting-edge genetic labeling strategies. You should also look at the large catalog of AAVs for optogenetics research on the U Penn vector core site as a more cost effective way to get started:

http://www.med.upenn.edu/gtp/vectorcore/Catalogue.shtml

The EF1a promoter is most useful for Cre dependent expression strategies (e.g. DIO designs), whereas the CaMKIIa or hSyn1 will work well for direct expression in WT animals). Lief and Anton are quite the experts so it would be worth looking over their published work on the topic.