This is a picture of a descending interneuron from the myenteric plexus of the guinea pig distal ileum that was impaled with an intracellular recording micropippette. The neuron was recorded from and then filled with a marker substance. The recordings were made while this neuron was responding to challenge of the gut with various chemical substances. Later processing of the tissue allowed the marker to be visualized with a microscope outfitted with a confocal scanning laser. The neuron's morphology was that of a Dogiel type I neuron with lamellar dendrites and a single axon (projecting off the bottom of the picture). These type of neurons are responsible for the continued flow of information about conditions in the upper gut to the regions below.

Read more about scary intestinal issues at The Why Files and see the scary neuron .