WANG, J.H*; CAIN, S.D.; LOHMANN, K.J.: The identification and characterization of magnetically sensitive neurons in Tritonia diomedea

Numerous behavioral studies show that diverse organisms use the earth’s magnetic field for orientation and navigation. Despite over three decades of interest in this behavioral phenomenon, little is known about the neural mechanisms that underlie this ability. In previous studies, Tritonia diomedea was shown to detect the earth’s magnetic field and use it as a cue for orientation. Subsequent neurophysiological work determined that the bilaterally symmetric neurons, left pedal 5 (LPd5) and right pedal 5 (RPd5), in the brain of Tritonia increased their electrical activity in response to rotations of the magnetic field. In this study, we present evidence showing that the left and right pedal 6 (L and RPd6) and left and right pedal 7 (L and RPd7) neurons in Tritonia respond to changes of the magnetic field. During rotations of the magnetic field, L and RPd6 increased their spike firing frequencies while L and RPd7 decreased their spike firing rates. In addition, anatomical and electrophysiological data suggested that these neurons innervate the ipsilateral foot epithelium. These results indicate that the Pd6 and Pd7 neurons may play a locomotory role in the neural circuitry underlying magnetic orientation in Tritonia diomedea.