Alexandra Kretz

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The retina is an easily accessible part of the CNS with a well-defined cytological architecture. It allows for detailed study of the regulation of neurogenesis, determinants of cell fate specification, and signals for cell survival versus programmed cellular death during development. Within the retina, retinal ganglion cells (RGCs) are the only neurons(More)
OBJECT To investigate the potential of a clinical 3 T scanner to perform MRI of small rodents. MATERIALS AND METHODS Different dedicated small animal coils and several imaging sequences were evaluated to optimize image quality with respect to SNR, contrast and spatial resolution. As an application, optimal grey-white-matter contrast and resolution were(More)
In the naïve adult rodent eye cell proliferation does not occur. The aim of this in vivo study was to evaluate if quiescent putative progenitor-like cells within the adult mouse eye can be activated by optic nerve (ON) injury. For a comprehensive analysis, three areas were assessed: the ON, the neural retina, and the ciliary body (CB). Two lesion types were(More)
Following transection of the optic nerve (ON) in the adult rat, retinal ganglion cells (RGCs) undergo degeneration, and within 14 days 85% of axotomized RGCs die by apoptosis. Adenoviral delivery of the mammalian caspase inhibitor X-chromosome-linked inhibitor of apoptosis (Ad.XIAP) to the ON stump leads to expression exclusively in RGCs and rescues 18.9%(More)
The development of the retino-tectal projection as part of the central visual pathway is accomplished around postnatal day (P) 10-14 in rodents, and trophic factors are important for topographic refinement of this projection. Emerging data indicate that GDNF may influence synaptic plasticity of this projection. To date, maturation-dependent kinetics of GDNF(More)
NF-κB is dually involved in neurogenesis and brain pathology. Here, we addressed its role in adult axoneogenesis by generating mutations of RelA (p65) and p50 (also known as NFKB1) heterodimers of canonical NF-κB. In addition to RelA activation in astrocytes, optic nerve axonotmesis caused a hitherto unrecognized induction of RelA in growth-inhibitory(More)
Traditionally, depiction of isolated CNS fiber tracts is achieved by histological post mortem studies. As a tracer-dependent strategy, the calcium analog manganese has proved valuable for in vivo imaging of CNS trajectories, particularly in rats. However, adequate protocols in mice are still rare. To take advantage of the numerous genetic mouse mutants that(More)
The regenerative potential of adult mammalian CNS neurons is limited. Recent data suggest that inactivation of major growth inhibitors may not suffice to induce robust regeneration from mature neurons unless the intrinsic growth state is modulated. To investigate a possible role of Bcl-XL for axon regeneration in the adult mammalian CNS, Bcl-XL was(More)
The rodent visual system encompasses retinal ganglion cells and their axons that form the optic nerve to enter thalamic and midbrain centers, and postsynaptic projections to the visual cortex. Based on its distinct anatomical structure and convenient accessibility, it has become the favored structure for studies on neuronal survival, axonal regeneration,(More)