Using an Artificial Neural Network to Identify an Interneuron in a Leech Sensory Circuit

OSCAR FILEVICH; ANTONIA MARIN BURGIN; LIDIA SZCZUPAK

Boston, Massachussets

Congreso; Boston Area Neuroscience Group; 1999

Boston Area Neuroscience Group (Society For Neuroscience)

The leech Hirudo Medicinalis is used as a model system to explore the mechanisms of serotoninergic modulation of the pathways involved in the collection of sensorial information and the execution of motor output. The two Retzius (Rz) cells in each body segment ganglion of the leech contain more than 50% of the total serotonin in this nervous system, and these cells are strongly depolarized via a polysinaptic pathway following stimulation of the pressure-sensitive (P) neurons. To identify the unknown interneurons involved in this pathway we trained an artificial neural network to the observed biological behavior, and found that some of the solutions obtained for the system included inhibitory components in the network. To further test this possibility, strychnine was applied to the bath in the biological preparation, and the stimulation protocol was repeated, for which a stronger depolarization was observed, favoring the hypothesis that inhibitory components are present in the P-Rz pathway.