Terence Smith: imaging complex neuronal behavior in the enteric nervous system

I went to a fascinating seminar today at UCL given by Terence Smith of the University of Nevada. He was talking about his work on the enteric nervous system. Turnout was low - most of us are not that excited by anything without "hippocampus" in the title! But I was glad I went. Prof Smith described this fine mesh of ganglia and interconnecting fibres sitting between the smooth muscle layers of the gut. Did you know that the ENS has as many neurons as the spinal cord?! And what a fascinating array of neuron types - sensory, excitatory motor, inhibitory motor, pacemaker and many varieties of interneuron. All talking to each other by means of strange and unfamiliar (at least to me) neurotransmitters - 5HT, acetyl choline, ATP, NO and suchlike. Prof Smith and his lab have been using calcium sensitive dyes to track patterns of neuronal activation. The nice thing about the ENS is that it is a mammalian system that is also a tractable problem - at least compared with brain areas like the hippocampus. A relatively simple circuit producing a relatively small repertoire of "behaviours" - it should be possible to get to the bottom of this in the next few decades. Which is more than we could hope for with the hippocampus for example....