Can I extend display of new 2015 Retina Macbook Pro to my older 2009 Macbook pro?

Can I extend display of new 2015 Retina Macbook Pro to my older 2009 Macbook pro, which has Mini-display port, Firewire, and USB? Connect 2015 MBP Thunderbolt to 2009 MBP Mini-display? I've researched a lot and it seems that I could connect my 2015 MBP from its Thunderbolt port to Monitor using its Mini-Display port and have it work. I just can't find anything that specifically states if it will work between 2 macbook pros the same way. A friend suggested I could use the HDMI port of the 2015 MBP through an adapter to connect to the 2009 MBP Mini-display port. I haven't been able to get it to work. Since mini-display port connector is physically the same as the Thunderbolt connector, and Thunderbolt is based on mini-display port technology, couldn't it work? I'm trying to find out before I go start wasting money on cables that won't work.

It has been suggested that I try something like screenrecycler.com, but although it worked, it was slow and choppy - at least the trial version was. I've used Synergy to create a virtual KVM between my iMac and a PC at work, but nothing in its literature says anything about it being capable of extending the display of one computer to another computer with the exact same OS.

I can always fall back on something like screen recycler, but just wondering if there really is a better performing answer.

Thank you,