[Abstract Title]. - Society for Neuroscience

CIHR
Title: Connexin32 expression is under hormonal control in the adult female mouse spinal cord
Authors: *A. C. MCLEAN 1 , S. A. L. BENNETT 2 ;
2 Dept. of Biochemistry, Microbiology and Immunol., 1 Univ. of Ottawa, Ottawa, ON, Canada
Abstract: Connexin32 (Cx32) is expressed by mature oligodendrocytes and a subset of early
oligodendrocyte progenitor cells in the adult murine central nervous system. Connexin
expression across various tissues has been proven to be under hormonal regulation by estrogen
and/or progesterone. Previously, we have demonstrated that Cx32 expression is under estrogenspecific
regulation within the hippocampus of the brain. Here we establish that Cx32 is under
hormonal control within the spinal cord in adult female C57BL/6 mice. To determine expression
levels over the estrous cycle, the T11-T13 region of spinal cord were dissected from females
during estrus, metestrus/diestrus, and proestrus. mRNA was quantified using qPCR. Perfused
tissue was sectioned and Cx32 was visualized by immunofluorescence. Cell types were
delineated by colabelling with antigenic lineage markers for mature oligodendrocytes and early
oligodendrocyte progenitors. Protein quantification was assessed by immunoprecipitation and
western blot analysis. Cx32 was visualized by immunofluorescence and colabeled with antigenic
lineage markers. To ensure specificity, congenic Cx32 null-mutant female mice were used as
negative controls. MULAN promoter analysis was performed to detect estrogen or progesterone
responsive elements in the Cx32 promoter. We have determined Cx32 mRNA and protein
expression levels are suppressed during proestrus when estrogen and progesterone levels are
highest and maximal during estrus when ovarian hormone levels are lowest. We show that Cx32
expression at both the mRNA and protein level fluctuates in the T11-T13 region of the spinal
cord over the course of estrous. These results demonstrate that Cx32 expression is under the
control of ovarian steroid hormones in the central nervous system of adult female mice.
Disclosures: A.C. McLean , None; S.A.L. Bennett, None.
Poster
241. Glial Neuronal Interactions
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 241.15/G9
Topic: B.11.b. Cell biology and signalling
Support: NMSS RG3669
NS 25304