Affiliations: Department of Neuroscience, Neurosurgery, Uppsala
University, Uppsala University Hospital, Uppsala, Sweden | Department of Neuroscience, Developmental
Neuroscience, Uppsala University, Biomedical Center, Uppsala, Sweden | Department of Genetics and Pathology, Uppsala
University, Rudbeck Laboratory, Uppsala, Sweden
Note: [] Corresponding author: Anders Lewén, MD, PhD, Department of
Neuroscience, Neurosurgery, Uppsala University Hospital, SE-751 85 Uppsala,
Sweden. Tel.: +46 18 611 49 69; Fax: +46 18 55 86 17; E-mail:
[email protected]
Abstract: Purpose: Astroglial responses after traumatic brain injury are
difficult to detect with routine morphological methods. The aims for this study
were to compare the temporal and spatial expression pattern of vimentin- and
glial fibrillary acidic protein (GFAP) in a weight drop model of mild cerebral
contusion injury in the rat. We also wanted to study the vimentin response with
immunohistochemistry and vimentin mRNA RT-PCR analysis in severe cortical
contusion injury produced by the controlled cortical impact in the mouse. Methods: Vimentin and GFAP immunohistochemistry (1day, 3 days and 7 days)
combined with vimentin mRNA RT-PCR analysis (1 h, 4 h, 22 h, 3 days and 7 days)
were used after experimental traumatic brain injury in the rat and mouse. Results: Increases in post-traumatic vimentin mRNA levels in the cortex and in
the hippocampus appeared together with vimentin immunoreactivity in astrocytes
in the perimeter of the cortical lesion, in the subcortical white matter and in
the hippocampus starting at one day after severe trauma. GFAP immunostaining
revealed hypertrophic astrocytes peaking at day 3 in the perifocal cortical
region. There was no significant increase in GFAP immunoreactivity in the white
matter in the rat. However, in the mouse there was a slight increase in the
number of GFAP positive cells in this region, 3 days after trauma. Overall the
pattern of vimentin immunoreactivity was very similar in the rat and mouse. Conclusions: Vimentin immunoreactivity was more sensitive than the GFAP
staining method to demonstrate the distribution and time course of astrocyte
reactions after a contusion injury, especially in the white matter distant from
the cortical lesion.
Keywords: Traumatic brain injury, rat, mouse, astrocytes, gliosis
