Premium
Insulin‐like growth factor 1 is essential for normal dendritic growth
Author(s) -
Cheng Clara M.,
Mervis Ronald F.,
Niu ShuiLin,
Salem Norman,
Witters Lee A.,
Tseng Victor,
Reinhardt Rickey,
Bondy Carolyn A.
Publication year - 2003
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.10634
Subject(s) - synaptogenesis , dendritic spine , biology , soma , endocrinology , neuron , neurogenesis , dendrite (mathematics) , medicine , golgi apparatus , synapse , microbiology and biotechnology , neuroscience , geometry , endoplasmic reticulum , mathematics , hippocampal formation
This study evaluated somatic and dendritic growth of neurons in the frontoparietal cortex of Igf1 –/– brains. Pyramidal neuron density was increased by ∼25% ( P = .005) and soma size reduced by ∼10% ( P < .001). Golgi staining revealed that cortical layer II–III neurons exhibited a significant reduction in dendritic length and complexity in Igf1 null mice. Dendritic spine density and presumably synaptic contacts were reduced by 16% ( P = .002). Similar findings were obtained for cortical layer V and piriform cortex pyramids. Supporting a reduction in synapses, synaptotagmin levels were reduced by 30% ( P < .02) in the Igf1 null brain. Investigation of factors critically involved in dendritic growth and synaptogenesis showed an ∼50% reduction in cortical CDC42 protein expression ( P < .001) and an ∼10% reduction in brain cholesterol levels ( P < .01) in Igf1 null mice. Evidence is presented that Igf1 deletion causes disruptions in lipid and microtubule metabolism, leading to impaired neuronal somatic and dendritic growth. Published 2003 Wiley‐Liss, Inc.