As reported earlier, I've now been working for a couple of days in Bill Kristan's lab at UCSD in La Jolla, California. The first few days I was practicing the dissection of the leech nervous system. I need to take the entire nervous system out of the animal, place it in a petri dish and then attach electrodes to the prepration to record the nervous activity as well as stimulate the nervous system electrically. Here's a video showing the reuslts of my first dissection  (actually, Bill did most of it, showing me the ropes):



By the middle of last week I had learned the dissection as well as how to record and stimulate using sucktion electrodes. This video shows one of the first recordings I made:



The to me really interesting and exciting thing was the spontaneous activity in this preparation (and with most others since then). With absolutely no stimulation whatsoever (remember, this is a completely isolated nervous system) the nervous system started initiating swimming activity just so! This is a really convincing example of the capacity of nervous systems to be active and initiate actions in the absence of any releasing stimuli. Besides responding to external stimuli, brains always actively initiate activity, regardless of the environment. I would even make the claim that responding to the environment is a secondary trait that evolved as a means to channel spontaneous activity into adaptive states. The video above provides some very nice anecdotal evidence supporting the published, peer-reviewed data.