TY - JOUR T1 - Contribution of Excitatory Chloride Conductance in the Determination of the Direction of Traveling Waves in an Olfactory Center JF - The Journal of Neuroscience JO - J. Neurosci. SP - 2932 LP - 2938 DO - 10.1523/JNEUROSCI.23-07-02932.2003 VL - 23 IS - 7 AU - Satoshi Watanabe AU - Tsuyoshi Inoue AU - Yutaka Kirino Y1 - 2003/04/01 UR - http://www.jneurosci.org/content/23/7/2932.abstract N2 - Traveling waves have been found in the CNS of vertebrates and invertebrates. In the olfactory center [procerebrum (PC)] of the terrestrial slug Limax, periodic waves travel from the apex to the base with a frequency of ∼0.7 Hz. The oscillation and propagation of waves have been thought to be mediated by the mutual connections of bursting neurons in the PC. The direction of the wave is Cl− dependent, because lowering the Cl− concentration in the medium reverses the direction. The bursting neurons have a Cl−channel-coupled glutamate receptor (GluClR), and, using a calcium imaging technique, the receptor was found to be excitatory. Activation of the GluClR with its selective agonist ibotenate resulted in an increased frequency of the oscillatory neural activity recorded as a periodic local field potential. Depletion of cytoplasmic Cl− with Cl−-free saline abolished all of the ibotenate-induced effects. Perforated-patch-clamp recording in single PC neurons revealed a spatial difference in the Cl−-dependent periodic depolarizations in the bursting neurons, with a higher amplitude in the apical region. These results suggest the involvement of excitatory GluClRs in the unidirectional propagation of waves in the PC. ER -