The Journal of Neuroscience, January 1, 1998, 18(1):319-327
Postnatal Expression of Hu-Bcl-2 Gene in
Lurcher Mutant Mice Fails to Rescue Purkinje Cells but
Protects Inferior Olivary Neurons from Target-Related Cell Death
H. S.
Zanjani1, 2,
M. W.
Vogel4,
J. C.
Martinou3,
N.
Delhaye-Bouchaud1, and
J.
Mariani1
1 Laboratoire de Neurobiologie du Développement,
Institut des Neurosciences et Unité de Recherche Associée,
Centre National de la Recherche Scientifique 1488, Université
Pierre et Marie Curie, 75005 Paris, France, 2 Physiological
Science Department, University of California at Los Angeles, Los
Angeles, California 90095-1527, 3 Geneva Biomedical
Research Institute, Glaxo Wellcome Research and Development SA, 1228 Plan-les-Ouates, Geneva, Switzerland, and 4 Maryland
Psychiatric Research Center, University of Maryland Medical School,
Baltimore, Maryland 21228
The Lurcher mutant has been extensively studied as a
model for cell-autonomous and target-related cell death, yet there are still many unknowns concerning the mechanisms of neuronal degeneration in this mutant. As a key regulator of apoptosis, a bcl-2
transgene has been overexpressed in the heterozygous
Lurcher mutant to investigate the effects of BCL-2 on
two types of in vivo neuronal cell loss in
Lurcher: cell-autonomous Purkinje cell degeneration and
target-related olivary neuron death. Six adult +/Lc
mutants expressing a human bcl-2 transgene
(Hu-bcl-2) were generated by crossing
+/Lc mutants with NSE71 Hu-bcl-2
transgenic mice. Analysis of these brains showed that
bcl-2 overexpression did not prevent +/Lc
Purkinje cell degeneration, but it did rescue most olivary neurons from target-related cell death. Although the number of olivary neurons was
equivalent to wild-type numbers, the inferior olive nucleus was
significantly shorter in its rostrocaudal extent, suggesting that
olivary neurons are atrophied. We propose that Lurcher
gene action causes Purkinje cell degeneration independently of a
BCL-2-mediated pathway. Furthermore, although bcl-2
overexpression rescues olivary neurons from target-related cell death,
it does not prevent the atrophy associated with the loss of
target-related trophic support.
Key words:
olivary neurons; Purkinje cells; BCL-2; Lurcher mutant; programmed cell death; cerebellar
mutants
Copyright © 1998 Society for Neuroscience 0270-6474/98/181319-09$05.00/0