Department of Cellular Neurophysiology
Laboratory of Molecular Neurophysiology
By employing a complex of electrophysiological, video-imaging and molecular biological techniques, we seek to identify the main receptors responsible for calcium signalling pathways and localise the intracellular signalling cascades. Further, we work to develop a complex understanding of information processing in neuronal-glial circuits, thus contributing to a more inclusive theory of brain function, which emphasizes a continuous interplay of discreet neuronal networks with the reticular and internally continuous astroglial web.
Diversity of synaptic contacts between neural cells.
In the grey matter synapses may include (1) classic “tripartite” neuronal-neuronal contacts, enwrapped by an astroglial membrane; (2) neuronal glial synapses (which have already been shown for neuronal-astroglial (Jabs and others 2005) or neuronal-NG2 cell contacts (Lin and Bergles, 2004); (3) astroglial-neuronal synapses (which are yet to be discovered); and (4) astroglial-astroglial synapses, which may exist as electrical/gap junctional or chemical contacts. In the white matter astrocytes may act as presynaptic elements in astroglial-oligodendroglial synapses (5).
Glutamate mediated neuronal-glial signalling.
Synaptically released glutamate activates glial ionotropic (AMPA and NMDA) and metabotropic receptors. Activation of group I metabotropic receptors initiates phospholipase C-dependent synthesis of InsP3, which, in turn, triggers Ca2+ release from the endoplasmic reticulum (ER) Ca2+ store. The majority (~ 80%) of glutamate released during synaptic transmission is taken up by astroglial Na+/glutamate transporters; subsequently glutamate is converted into glutamine, which is transported back to neurones, where it acts as a main source of newly synthesised glutamate (“glutamate-glutamine shuttle”).
Membrane properties of GFP-labeled primary embryonic stem cells during differentiation.
(A) Green fluorescent protein (GFP)-labeled primary embryonic stem cells (D6/GFP) express the typical neuronal markers βIII-tubulin, MAP-2 and DCX (doublecortin), six days after in vitro differentiation. (B) A typical current pattern of D6/GFP-derived neuron-like cells.
