Neural control of feeding

Because the buccal ganglia have only about 400 cells, but control much of feeding, snails' feeding behaviour has been extensively studied. The buccal ganglia have nerves which run over the buccal muscles and innervate the oral cavity. thie biggest neurons innervate the buccal muscle which control rasping at the food (eg. lettuce). Here are two views of the buccal ganglia of Lymnaea stagnalis, which has yellow-orange colored neurons
 
Picture of the buccal ganglia
Picture of the buccal ganglia with one neuron stained
Picture of the buccal ganglia, showing some of the 400 neurons: click the picture for more details, including a partial map  Picture of the buccal ganglia, using a blue laser to illuminate just one of the neurons (glowing yellow). You can also see the micropipettes (black) used to record from the neurons, and to fill one of them with the fluorescent dye Lucifer yellow
Picture of a B2 motoneuron Picture of the B2 motoneuron of the left buccal ganglion of Lymnaea stagnalis, filled with the fluorescent dye Lucifer yellow by Thomas Patchett on work experience. The cell shines brightly illuminated with blue light; the rest of the ganglion is dark as the orange pigment has been removed by fixing the dye to proteins using formaldyehyde and then dehydrateing the ganglion with ethanola nd placing it in methyl salicylate. Note the bright axon running left and upwards into the oesophagus, and the branches (dendrites) where it makes contact with other feeding neurons. 

Click the picture for a larger view

 
Read On: More about the buccal ganglia

Page edited by Chris Elliott, 06 nov 2003