TY - JOUR
T1 - Expression of insulin‐like growth factor binding protein‐4 and ‐5 mRNAs in adult rat forebrain
AU - Stenvers, Kaye L.
AU - Zimmermann, Ellen M.
AU - Gallagher, Michela
AU - Lund, P. Kay
PY - 1994/1/1
Y1 - 1994/1/1
N2 - Accumulating evidence indicates that the insulin‐like growth factors (IGFs) can act as neurotrophic factors. A family of at least six IGF binding proteins (IGFBPs) has been characterized. The IGFBPs prolong the half‐life of IGFs in plasma and may modulate IGF action in a cell‐ or tissue‐specific fashion. Two recently characterized IGFBPs, IGFBP‐4 and ‐5, have been shown by northern blot hybridization to be expressed in rat brain, but their cellular sites of synthesis are poorly characterized. Because IGFBP‐4 and IGFBP‐5 could potentially modulate IGF actions in the brain, we used in situ hybridization histochemistry and 35S‐labeled IGFBP‐4 and IGFBP‐5 riboprobes to localize sites of IGFBP‐4 and ‐5 mRNA expression in adult rat brain. The two IGFBP mRNAs are abundantly expressed within discrete regions of brain. The expression patterns of the two genes are largely nonoverlapping. Notably, IGFBP‐4 mRNA is highly expressed within hippocampal and cortical areas, whereas IGFBP‐5 mRNA is not detected above background in these areas. Within the hippocampus, abundant IGFBP‐4 mRNA expression is detected in pyramidal neurons of the subfields of Ammon's horn and the subiculum and in the granule cell layer of the anterior hippocampal continuation. In the cortex, IGFBP‐4 mRNA is widely expressed in most areas and layers. In contrast, IGFBP‐5, but not IGFBP‐4, mRNA is detected within thalamic nuclei, leptomeninges, and perivascular sheaths. The distinct expression patterns of IGFBP‐4 and ‐5 mRNAs within the brain suggest that these IGFBPs may modulate paracrine/autocrine actions of the IGFs in discrete brain regions or compartmentalization of the IGFs within the brain. © 1994 Wiley‐Liss, Inc.
AB - Accumulating evidence indicates that the insulin‐like growth factors (IGFs) can act as neurotrophic factors. A family of at least six IGF binding proteins (IGFBPs) has been characterized. The IGFBPs prolong the half‐life of IGFs in plasma and may modulate IGF action in a cell‐ or tissue‐specific fashion. Two recently characterized IGFBPs, IGFBP‐4 and ‐5, have been shown by northern blot hybridization to be expressed in rat brain, but their cellular sites of synthesis are poorly characterized. Because IGFBP‐4 and IGFBP‐5 could potentially modulate IGF actions in the brain, we used in situ hybridization histochemistry and 35S‐labeled IGFBP‐4 and IGFBP‐5 riboprobes to localize sites of IGFBP‐4 and ‐5 mRNA expression in adult rat brain. The two IGFBP mRNAs are abundantly expressed within discrete regions of brain. The expression patterns of the two genes are largely nonoverlapping. Notably, IGFBP‐4 mRNA is highly expressed within hippocampal and cortical areas, whereas IGFBP‐5 mRNA is not detected above background in these areas. Within the hippocampus, abundant IGFBP‐4 mRNA expression is detected in pyramidal neurons of the subfields of Ammon's horn and the subiculum and in the granule cell layer of the anterior hippocampal continuation. In the cortex, IGFBP‐4 mRNA is widely expressed in most areas and layers. In contrast, IGFBP‐5, but not IGFBP‐4, mRNA is detected within thalamic nuclei, leptomeninges, and perivascular sheaths. The distinct expression patterns of IGFBP‐4 and ‐5 mRNAs within the brain suggest that these IGFBPs may modulate paracrine/autocrine actions of the IGFs in discrete brain regions or compartmentalization of the IGFs within the brain. © 1994 Wiley‐Liss, Inc.
KW - cortex
KW - hippocampus
KW - in situ hybridization
KW - leptomeninges
KW - thalamus
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U2 - 10.1002/cne.903390109
DO - 10.1002/cne.903390109
M3 - Article
C2 - 7508953
AN - SCOPUS:0028366497
SN - 0021-9967
VL - 339
SP - 91
EP - 105
JO - Journal of Comparative Neurology
JF - Journal of Comparative Neurology
IS - 1
ER -