ヤスヤマ コウジ   Kouji Yasuyama
  泰山 浩司
   所属   川崎医療福祉大学  リハビリテーション学部 言語聴覚療法学科
   職種   特任教授
論文種別 原著
言語種別 英語
査読の有無 査読あり
表題 Synaptic organization of the mushroom body calyx in Drosophila melanogaster.
掲載誌名 正式名:The Journal of comparative neurology
略  称:J Comp Neurol
ISSNコード:00219967/10969861
巻・号・頁 445(3),pp.211-226
著者・共著者 Yasuyama Kouji, Meinertzhagen Ian A., Schürmann Friedrich-Wilhelm
担当区分 筆頭著者
発行年月 2002/04
概要 The projection neurons connecting the calyx with the antennal lobe via the antennocerebral tract are the only source of cholinergic elements in the calyces. Their terminals establish an array of large boutons 2–7um in diameter throughout all calycal subdivisions. The GABA-ir extrinsic neurons, different in origin, form a network of fine fibers and boutons codistributed in all calycal regions with the cholinergic terminals and with tiny profiles, mainly Kenyon cell dendrites. We have investigated the synaptic circuits of these three neuron types using preembedding immunoelectron microscopy. All ChAT/VAChT-ir boutons form divergent synapses upon multitudinous surrounding Kenyon cell dendrites. GABA-ir elements also regularly contribute divergent synaptic input onto these dendrites, as well as occasional inputs to boutons of projection neurons. The same synaptic microcircuits involving these three neuron types are repeatedly established in glomeruli in all calycal regions. Each glomerulus comprises a large cholinergic bouton at its core, encircled by tiny vesicle-free Kenyon cell dendrites as well as by a number of GABAergic terminals. A single dendritic profile may thereby receive synaptic input from both cholinergic and GABAergic elements in close vicinity at presynaptic sites with T-bars typical of fly synapses. ChAT-ir boutons regularly have large extensions of the active zones. Thus, Kenyon cells may receive major excitatory input from cholinergic boutons and considerable postsynaptic inhibition from GABAergic terminals, as well as, more rarely, presynaptic inhibitory signaling. The calycal glomeruli of Drosophila are compared with the cerebellar glomeruli of vertebrates. The cholinergic boutons are the largest identified cholinergic synapses in the Drosophila brain and an eligible prospect for studying the genetic regulation of excitatory presynaptic function.
DOI 10.1002/cne.10155