Can I use a thunderbolt cable instead of Mini DisplayPort cable?

My iMac has a mini displayport input, and my MacBook air has a thunderbolt port.

ideally, I would connect the two using a Mini DisplayPort cable to use target display mode. But Mini DisplayPort cables are hard to come by, so can I use a thunderbolt cable instead?

tthunderbolt is supposed to be backward compatible with DisplayPort, hence my question. I know the reverse cannot be done.