A Metabotropic Glutamate Receptor Mediates Synaptic Transmission from Blue-Sensitive Cones to ON-Bipolar Cells in Carp Retina

  • Hiroshi Joho
  • Richard Shiells
  • Masahiro Yamada
Conference paper
Part of the Keio University International Symposia for Life Sciences and Medicine book series (KEIO, volume 11)


Glutamate receptors mediate synaptic transmission from photoreceptors to bipolar cells in the vertebrate retina. L-2-amino-4-phosphonobutyrate (L-APB), a group III metabotropic glutamate receptor (mGluR) agonist, was used to identify mGluR6, which mediates rod synaptic input to ON-bipolar cells. A presynaptic mGluR has been similarly identified on red-sensitive cone synaptic terminals [1]. Whether a post-synaptic mGluR is involved in signaling from red-, green-, or blue-sensitive cones to ON-bipolar cells has not, however, been determined in the teleost retina. To characterize the postsynaptic glutamate receptor, electroretinogram (ERG) b-waves (a measure of ON-bipolar cell activity) and intracellular responses from cones to trichromatic stimuli (blue, 455 nm; green, 549 nm; and red, 694 nm) were recorded from light-adapted isolated carp retina.

Key words

mGluR Blue-sensitive cones ON-bipolar cells 


  1. 1.
    Hirasawa H, Shiells R, Yamada M (2002) A metabotropic glutamate receptor regulates transmitter release from cone presynaptic terminals in carp retinal slices. J Gen Physiol 119: 55–68PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Tokyo 2003

Authors and Affiliations

  • Hiroshi Joho
    • 1
    • 2
  • Richard Shiells
    • 3
  • Masahiro Yamada
    • 1
  1. 1.Tokyo Metropolitan Institute of TechnologyHinoTokyoJapan
  2. 2.Yamanouchi Pharmaceutical Co. LtdItahashiTokyoJapan
  3. 3.Physiology DepartmentUniversity College LondonLondonUK

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