Different postischemic protein expression of the
GABA_{A} receptor α2 subunit and
the plasticity-associated protein MAP1B after treatment with BDNF versus G-CSF
in the rat brain
Affiliations: Division of Neuropathology, Bezirkskrankenhaus
Günzburg, Günzburg, Germany | Department of Neuropathology, University of Mainz,
Mainz, Germany | Laboratory of Neuropathology, University of Ulm, Ulm,
Germany | Department of Neurology, University of Heidelberg,
Heidelberg, Germany | Department of Neurology, University of Münster,
Münster, Germany
Note: [] Corresponding author: Clemens Sommer, MD, Department of
Neuropathology, Mainz University Medical Center, Langenbeckstrasse 1, D-55131
Mainz, Germany. Tel.: +49 6131 17 3213; Fax: +49 6131 17 6606; E-mail:
sommer@neuropatho.klinik.uni-mainz.de
Abstract: Purpose: Recent data indicate that both brain-derived neurotrophic
factor (BDNF) and granulocyte-colony stimulating factor (G-CSF) exert
substantial neuroregenerative effects and improve functional outcome after
ischemic stroke. In the present study, we checked for potential differences in
the postischemic modulation of various excitatory and inhibitory
neurotransmitter receptors as well as various marker molecules for structural
plasticity by BDNF versus G-CSF. Methods: Adult male Wistar rats were subjected to
photothrombotic ischemia and subsequently treated with NaCl, BDNF or G-CSF,
respectively. After 6 weeks, postischemic protein expression of the NR1, GluR1
and α2 subunit of the NMDA, AMPA and GABA_{A} receptor,
respectively, was semiquantitatively determined ipsi- and contralateral to the
ischemic lesion. Structural plasticity was further analyzed
immunohistochemically using antibodies against MAP1B, MAP2 and synaptophysin.
Results: Only BNDF caused a significantly reduced postischemic
protein expression of the GABA_{A} receptor α2 subunit and the NR1
subunit of the NMDA receptor in the hippocampus. Furthermore, BDNF compared to
G-CSF increased MAP1B protein expression in the periischemic regenerative
region. Conclusions: Although both BDNF and G-CSF have been shown to
improve postischemic functional outcome to a similar extent, exogenous
administration results in different underlying structural reorganization
processes suggesting specific modulations of plasticity-associated events by
these trophic factors.
