AUTOIMMUNE ENCEPHALOMYELITIS IS ACCOMPANIED BY THE INJURY OF HIPPOCAMPAL NEURONS

• Published in: Acta neurobiologiae experimentalis Vol. 69; no. 3; p. 321
• Main Authors: Kurkowska-Jastrzebska, I, Zaremba, M, Cudna, A, Piechal, A, Swiatkiewicz, M, Czlonkowska, A, Oderfeld-Nowak, B
• Format: Journal Article
• Language: English
• Published: 01.01.2009
• ISSN: 0065-1400

Multiple sclerosis (MS) is associated with cognitive deficits, developing independently from motor disorders. These deficits may be associated with brain neuronal damage. In this study, using the experimental model for MS - autoimmune encephalomyelitis (EAE), we investigated whether EAE will result in the damage of hippocampal neurons and selective deficits in learning and memory, and whether there may be a correlation between the two phenomena. Lewis rats 3 months old were injected with 4 millions of anti-MBP CD4+ T cells to evoke EAE. Animals suffered from tail and hind limb paresis and recovered after 10 dpi. T cells infiltrated spinal cord and many brain regions including hippocampus. We demonstrated the decrease of pyramidal neurons in CA4 region by about 20%, as evaluated by stereological measurements, at 21 dpi. This was preceded by prolonged glial activation as well as by a rise of the pro-inflammatory cytokine mRNA expression (IL-1 beta , IL-6 and TNF alpha ). However, no differences in the water maze test were detected between the EAE and control groups, on 21 dpi and on 90 dpi. In conclusion, anti-MBP CD4+ T cells are capable of injuring hippocampal pyramidal neurons during EAE, probably, through the secretion of pro-inflammatory cytokines. However, in the studied conditions, hippocampal neurodegeneration caused by T cells did not result in memory disturbances.