iMac doesn't see iPod

Hello, I'm using iTunes 11.2.2.(3) on an iMac running OS 10.6.8.

When I plug in my iPod (an antique 2G nano, 2nd generation I believe) via USB it doesn’t show up anywhere in iTunes (File/Devices doesn't see it), and it also doesn’t show up on the desktop like a CD or DVD would. Disc Utility doesn't see it.

I have tried restarting the iMac, both normally and in Safe Mode, and I've tried using different USB ports on the iMac.

How do I help the iMac see the iPod, so I can transfer stuff back and forth?

Thanks,

Ch.S.