TY - JOUR
T1 - Neonatal isolation accelerates the developmental switch in the signalling cascades for long-term potentiation induction
AU - Huang, Chiung Chun
AU - Chou, Pei Hsuan
AU - Yang, Chih Hao
AU - Hsu, Kuei Sen
PY - 2005/12/15
Y1 - 2005/12/15
N2 - The molecular mechanisms underlying long-term potentiation (LTP) in the CA1 region of the hippocampus are known to vary with developmental age. The physiological factors regulating this developmental change, however, have not yet been elucidated. Here we show that mild neonatal isolation accelerates the developmental switch in the signalling cascades for hippocampal CA1 LTP induction from a cyclic AMP-dependent protein kinase (PKA)- to a Ca2+/calmodulin-dependent protein kinase II (CaMKII)-dependent pattern via the activation of the corticotrophin-releasing factor (CRF) system. Furthermore, this action appears to be mediated through an increased transcription of the α isoform of the CaMKII (CaMKIIα) gene. We also demonstrate that application of CRF to cultured hippocampal neurones significantly increases the expression of CaMKIIα, which is blocked by the non-specific CRF receptor antagonist astressin, the specific CRF receptor 1 antagonist NBI 27911, and the PKA inhibitor KT5720, but not by the CRF receptor 2 antagonist K 41498, or the protein kinase C inhibitor, bisindolylmaleimide I. CRF signalling also mediates the normal maturation of LTP. These results suggest a novel role for CRF in regulating early developmental events in the hippocampus, and indicate that, although maternal deprivation is stressful for the neonate, appropriate neonatal isolation can serve to promote an endocrine state that fosters the rate of maturation of the signalling cascades underlying the induction of LTP in the developing hippocampus.
AB - The molecular mechanisms underlying long-term potentiation (LTP) in the CA1 region of the hippocampus are known to vary with developmental age. The physiological factors regulating this developmental change, however, have not yet been elucidated. Here we show that mild neonatal isolation accelerates the developmental switch in the signalling cascades for hippocampal CA1 LTP induction from a cyclic AMP-dependent protein kinase (PKA)- to a Ca2+/calmodulin-dependent protein kinase II (CaMKII)-dependent pattern via the activation of the corticotrophin-releasing factor (CRF) system. Furthermore, this action appears to be mediated through an increased transcription of the α isoform of the CaMKII (CaMKIIα) gene. We also demonstrate that application of CRF to cultured hippocampal neurones significantly increases the expression of CaMKIIα, which is blocked by the non-specific CRF receptor antagonist astressin, the specific CRF receptor 1 antagonist NBI 27911, and the PKA inhibitor KT5720, but not by the CRF receptor 2 antagonist K 41498, or the protein kinase C inhibitor, bisindolylmaleimide I. CRF signalling also mediates the normal maturation of LTP. These results suggest a novel role for CRF in regulating early developmental events in the hippocampus, and indicate that, although maternal deprivation is stressful for the neonate, appropriate neonatal isolation can serve to promote an endocrine state that fosters the rate of maturation of the signalling cascades underlying the induction of LTP in the developing hippocampus.
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U2 - 10.1113/jphysiol.2005.098160
DO - 10.1113/jphysiol.2005.098160
M3 - Article
C2 - 16223759
AN - SCOPUS:29244469096
SN - 0022-3751
VL - 569
SP - 789
EP - 799
JO - Journal of Physiology
JF - Journal of Physiology
IS - 3
ER -