Glial and neuronal connexin expression patterns in the rat spinal cord during development and following injury

TY - JOUR

T1 - Glial and neuronal connexin expression patterns in the rat spinal cord during development and following injury

AU - Lee, I. Hui

AU - Lindqvist, Eva

AU - Kiehn, Ole

AU - Widenfalk, Johan

AU - Olson, Lars

PY - 2005/8/15

Y1 - 2005/8/15

N2 - Spinal cord injury induces a complex cascade of degenerative and remodeling events evolving over time. The possible roles of changed intercellular communication via gap junctions after spinal cord injury (SCI) have remained relatively unexplored. We investigated the temporospatial expression patterns of gap junctional genes and proteins, connexin 43 (Cx43), Cx36, and Cx32, by in situ hybridization and immunohistochemistry in the rat neonatal, adult normal, and adult injured spinal cord. Cx36 was strongly expressed in immature neurons, and levels declined markedly during development, whereas Cx43 and Cx32 persisted throughout adulthood. After a complete transection of the adult spinal cord, the levels of Cx43 mRNA and protein were up-regulated within hours, especially in gray matter rostral to the lesion, reaching over three times normal levels at 4 weeks postinjury. Cx43 immunoreactivity was seen primarily in astrocytes and rarely in microglia. In contrast, Cx36 and Cx32 mRNA and proteins were relatively sparse and unchanged after spinal cord injury along the entire axis of the spinal cord. Cx43 is the most abundant gap junctional protein in the adult CNS and has been shown to form channels between astrocytes as well as between astrocytes and oligodendrocytes. Long-term up-regulation of Cx43 in reactive astrocytes may be one critical component in the rearrangement of the local astroglial network following SCI.

AB - Spinal cord injury induces a complex cascade of degenerative and remodeling events evolving over time. The possible roles of changed intercellular communication via gap junctions after spinal cord injury (SCI) have remained relatively unexplored. We investigated the temporospatial expression patterns of gap junctional genes and proteins, connexin 43 (Cx43), Cx36, and Cx32, by in situ hybridization and immunohistochemistry in the rat neonatal, adult normal, and adult injured spinal cord. Cx36 was strongly expressed in immature neurons, and levels declined markedly during development, whereas Cx43 and Cx32 persisted throughout adulthood. After a complete transection of the adult spinal cord, the levels of Cx43 mRNA and protein were up-regulated within hours, especially in gray matter rostral to the lesion, reaching over three times normal levels at 4 weeks postinjury. Cx43 immunoreactivity was seen primarily in astrocytes and rarely in microglia. In contrast, Cx36 and Cx32 mRNA and proteins were relatively sparse and unchanged after spinal cord injury along the entire axis of the spinal cord. Cx43 is the most abundant gap junctional protein in the adult CNS and has been shown to form channels between astrocytes as well as between astrocytes and oligodendrocytes. Long-term up-regulation of Cx43 in reactive astrocytes may be one critical component in the rearrangement of the local astroglial network following SCI.

KW - Astrocyte

KW - Gap junction

KW - Microglia

KW - Neuron

KW - Oligodendrocyte

UR - http://www.scopus.com/inward/record.url?scp=21644484590&partnerID=8YFLogxK

U2 - 10.1002/cne.20567

DO - 10.1002/cne.20567

M3 - Journal article

C2 - 15977163

AN - SCOPUS:21644484590

SN - 0021-9967

VL - 489

SP - 1

EP - 10

JO - Journal of Comparative Neurology

JF - Journal of Comparative Neurology

IS - 1

ER -