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In the NYTimes' ScienceTimes section on 3/6/07, there was an interesting short that caught my eye because it involves the two bio classes I'm currently taking--this course and developmental biology.According to researchers at Cornell, in embryonic zebra fish, neurons the ventral side of the developing spinal cord fire when the fish is swimming slowly, while neurons on the dorsal side fire when swimming quickly.  When zebra fish swim slowly, only the tail muscles are active, but while swimming quickly, the entire body is involved.For the developmental biologist, these studies have shown that different proteins are released from the dorsal and ventral sides of the spinal cord, and create concentration gradients which help in the differentiation of nerve cells.  From this information, it sounds like the cord secretes morphogens.  Knowing how cells become specified is quite important to the developmental biologist.For the neurobiologist, these patterns in firing look like they could have something to with central pattern generation.  But in order to say for sure, you would need to see the order of the neural firing--whether they're all firing at the same time or in a pattern like in the crayfish example, and if certain neurons are removed, what sort of effect does that have.It would be interesting to know how early these sorts of movement patterns develop.  This could give us information on how quickly the motorneurons are able to function in a zebra fish embryo.  Also, what are the other properties of these proteins secreted by the spinal cord? Are they only made during development or do they have another purpose in the grand-sceme of the zebra fish lifecycle?  One last question. If you somehow made a mutant that wouldn't be able to create the spinal cord proteins, how would that effect the neural firing and movement of the embryo?The wiring in the nervous system from zebra fish to humans is completely dependent upon the development of the particular organism.  We can change the neural connections in our brains by listening to a lecture and learning the material, but we wouldn't have any wiring to change if development hadn't proceded as planned.  (That's not to say that development is the same between all humans, there is infinite room for variations, as we've already covered).  I guess my point is that as we move forward in the course, I would like to explore neural development on a behavioral level.