Georg Hafner

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Georg Hafner
Ort Göttingen
Position PhD Student
Tel. +49-(0)551/39-7072
georg.hafner@med.uni-goettingen.de

Publikationen

    • 2017
    • Subcellular Targeting of VIP Boutons in Mouse Barrel Cortex is Layer-Dependent and not Restricted to Interneurons.
      Zhou,X.; Rickmann,M.; Hafner,G.; Staiger,J.F..
      Cerebral Cortex 27(11):5353-5368, 2017.
      abstract link

      Neocortical vasoactive intestinal polypeptide (VIP) expressing cells are a diverse subpopulation of GABAergic interneurons issuing distinct axonal projections. They are known to inhibit other types of interneurons as well as excitatory principal neurons and possess a disinhibitory net effect in cortical circuits. In order to elucidate their targeting specificity, the output connectivity of VIP interneurons was studied at the subcellular level in barrel cortex of interneuron-specific Cre-driver mice, using pre- and postembedding electron microscopy. Systematically sampling VIP boutons across all layers, we found a substantial proportion of the innervated subcellular structures were dendrites (80%), with somata (13%), and spines (7%) being much less targeted. In layer VI, a high proportion of axosomatic synapses was found (39%). GABA-immunopositive ratio was quantified among the targets using statistically validated thresholds: only 37% of the dendrites, 7% of the spines, and 26% of the somata showed above-threshold immunogold labeling. For the main target structure "dendrite", a higher proportion of GABAergic subcellular profiles existed in deep than in superficial layers. In conclusion, VIP interneurons innervate non-GABAergic excitatory neurons and interneurons at their subcellular domains with layer-dependent specificity. This suggests a diverse output of VIP interneurons, which predicts multiple functionality in cortical circuitry beyond disinhibition