オサキ ヒロノブ
  尾崎 弘展
   所属   医学部 医学科
   職種   助教
論文種別 原著
言語種別 英語
査読の有無 査読あり
表題 Effects of stimulus spatial frequency, size, and luminance contrast on orientation tuning of neurons in the dorsal lateral geniculate nucleus of cat.
掲載誌名 正式名:Neuroscience research
略  称:Neurosci Res
ISSNコード:1872-8111(Electronic)0168-0102(Linking)
巻・号・頁 77(3),143-54頁
著者・共著者 Naito Tomoyuki, Okamoto Masahiro, Sadakane Osamu, Shimegi Satoshi, Osaki Hironobu, Hara Shin-Ichiro, Kimura Akihiro, Ishikawa Ayako, Suematsu Naofumi, Sato Hiromichi
発行年月 2013/11
概要 It is generally thought that orientation selectivity first appears in the primary visual cortex (V1), whereas neurons in the lateral geniculate nucleus (LGN), an input source for V1, are thought to be insensitive to stimulus orientation. Here we show that increasing both the spatial frequency and size of the grating stimuli beyond their respective optimal values strongly enhance the orientation tuning of LGN neurons. The resulting orientation tuning was clearly contrast-invariant. Furthermore, blocking intrathalamic inhibition by iontophoretically administering γ-aminobutyric acid (GABA)A receptor antagonists, such as bicuculline and GABAzine, slightly but significantly weakened the contrast invariance. Our results suggest that orientation tuning in the LGN is caused by an elliptical classical receptive field and orientation-tuned surround suppression, and that its contrast invariance is ensured by local GABAA inhibition. This contrast-invariant orientation tuning in LGN neurons may contribute to the contrast-invariant orientation tuning seen in V1 neurons.
DOI 10.1016/j.neures.2013.08.009
文献番号 24055599