Semyanov Research Unit

We use electrophysiological and imaging techniques to reveal the functions of extrasynaptic interactions in the brain. This involves studying release and uptake of extrasynaptic signalling molecules, their diffusion in the extracellular space, and localisation and properties of their receptors.

Research Subjects

• Role of astrocytes in synaptic transmission and extrasynaptic signaling (Yulia Debbitskaya)
• Tonic activation of extrasynaptic GABA receptors in neurons (Yulia Dembitskaya)
• Functional role of cell compartment specific activation of extrasynaptic NMDA receptors (Maxim Doronin)
• Regulation of glutamate transporter function in astrocytes (Maxim Doronin)

Publications

1. Wu Y-W, Grebenyuk S, McHugh TJ, Rusakov DA, Semyanov A.:
   "Backpropagating action potentials enable detection of extrasynaptic glutamate by NMDA receptors "
   Cell Reports 2012, V.1, pp. 495-505, doi:10.1016/j.celrep.2012.03.007
2. Semyanov, A., Walker, M.C., Kullmann, D.M., and Silver, R.A.:
   "Tonically active GABAA receptors: modulating gain and maintaining the tone"
   Trends in Neurosciences, 27 262-269 (2004).
3. Semyanov, A., Walker, M.C., and Kullmann, D.M.:
   "GABA uptake regulates cortical excitability via cell type-specific tonic inhibition"
   Nature Neurosci., 6 484-490 (2003).
4. Semyanov, A. and Kullmann, D.M.:
   "Kainate receptor-dependent axonal depolarization and action potential initiation in interneurons"
   Nature Neurosci., 4, 718-723 (2001).
5. Semyanov, A. and Kullmann, D.M.:
   "Modulation of GABAergic signaling among interneurons by metabotropic glutamate receptors"
   Neuron, 25, 663-672 (2000).
6. Semyanov, A.:
   "Can diffuse extrasynaptic signaling form a guiding template"
   Neurochem Int. 2008 Jan;52(1-2):31-3
7. Rama S, Vetrivel L, and Semyanov A.:
   "Second-harmonic generation voltage imaging at subcellular resolution in rat hippocampal slices"
   J Biophotonics, 3(12), 784-90 (2010)
8. Mika Tanaka, Pei-Yu Shih, Hiroshi Gomi, Takamasa Yoshida, Junichi Nakai, Reiko Ando, Teiichi Furuichi, Katsuhiko Mikoshiba, Alexey Semyanov*, Shigeyoshi Itohara*:
   "Astrocytic Ca2+ signals are required for the functional integrity of tripartite synapses"
   Molecular Brain 2013, 6:6 doi: 10.1186/1756-6606-6-6.
9. Pavlov I, Savtchenko L, Kullmann DK, Semyanov A, Walker MC.:
   "Outwardly rectifying tonically active GABAA receptors in pyramidal cells modulate neuronal offset, not gain"
   J.Neurosci. 2009, 29(48):15341-15350
10. Song I, Savtchenko L, and Semyanov A.:
    "Tonic excitation or inhibition is set by GABA(A) conductance in hippocampal interneurons"
    Nat Commun, 2, 376 (2011)