Visualizing the connectivity of newly generated neurons in the adult dentate gyrus.

LOMBARDI GABRIELA; SCHINDER ALEJANDRO

Debrecen, Hungria

Workshop; Modern technologies in gene expression detection and data integration; 2006

HHMI y Clinical Genomics Center, University of Debrecen

Neural progenitor cells are highly abundant in the adult mammalian brain yet they give rise to neurons only in the so-called neurogenic regions: the subventricular zone of the lateral ventricles and the subgranular zone of the hippocampal dentate gyrus (DG). We and other have recently shown that neurons born in the adult hippocampus become integrated in the existing networks, supporting a functional role for neurogenesis in adult hippocampal function. While we have demonstrated that adult newborn granule cells develop for more than 6 weeks and receive functional GABAergic and glutamatergic afferents similar to those of DG cells generated during development, their output has never been studied. To label pairs of connected pre- postsynaptic neurons we will take advantage of wheat-germ agglutinin (WGA) a marker that, when expressed by a neuron, is transported anterogradely through the axon and jumps from the terminals to the postsynaptic dendrites of active synapses and labels postsynaptic neurons. WGA will be retrovirally expressed in dividing progenitor cells as a GFP fusion protein under the strong promoter. Retroviral constructs will be injected in the DG of adult mice. Upon differentiation, transduced neurons will therefore exhibit green fluorescence. With this methodology we will be analyze the synaptic connectivity.