Developmental genetic profiles of glutamate receptor system, neuromodulator system, protector of normal tissue and mitochondria, and reelin in marmoset cortex: potential molecular mechanisms of pruning phase of spines in primate synaptic formation process during the end of infancy and prepuberty (II).
This is the second report of a series paper, which reports molecular mechanisms underlying the occurrence of pruning spine phase after rapid spinogenesis phase in neonates and young infant in the primate brain. We performed microarray analysis between the peak of spine numbers [postnatal 3 months (M)] and spine pruning (postnatal 6M) in prefrontal, inferior temporal, and primary visual cortices of the common marmoset (Callithrix jacchus). The pruning phase is not clearly defined in rodents but is in primates including the marmoset. The differentially expressed genes between 3M and 6M in all three cortical areas were selected by two-way analysis of variance. The list of selected genes was analyzed by canonical pathway analysis using "Ingenuity Pathway Analysis of complex omics data" (IPA; Ingenuity Systems, Qiagen, Hilden, Germany). In this report, we discuss these lists of genes for the glutamate receptor system, G-protein-coupled neuromodulator system, protector of normal tissue and mitochondria, and reelin. (1) Glutamate is a common neurotransmitter. Its receptors AMPA1, GRIK1, and their scaffold protein DLG4 decreased as spine numbers decreased. Instead, GRIN3 (NMDA receptor) increased, suggesting that strong NMDA excitatory currents may be required for a single neuron to receive sufficient net synaptic activity in order to compensate for the decrease in synapse. (2) Most of the G protein-coupled receptor genes (e.g., ADRA1D, HTR2A, HTR4, and DRD1) in the selected list were upregulated at 6M. The downstream gene ROCK2 in these receptor systems plays a role of decreasing synapses, and ROCK2 decreased at 6M. (3) Synaptic phagosytosis by microglia with complement and other cytokines could cause damage to normal tissue and mitochondria. SOD1, XIAP, CD46, and CD55, which play protective roles in normal tissue and mitochondria, showed higher expression at 6M than at 3M, suggesting that normal brain tissue is more protected at 6M. (4) Reelin has an important role in cortical layer formation. In addition, RELN and three different pathways of reelin were expressed at 6M, suggesting that new synapse formation decreased at that age. Moreover, if new synapses were formed, their positions were free and probably dependent on activity.
Department of Ultrastructural Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan.
Tetsuya
T
Sasaki
Department of Ultrastructural Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan; Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka 560-8531, Japan.
Tomofumi
T
Oga
Department of Ultrastructural Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan.
Keiko
K
Nakagaki
Department of Ultrastructural Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan.
Kazuhisa
K
Sakai
Environmental Health Science Laboratory, Sumitomo Chemical Co., Ltd., 3-1-98 Kasugade-naka, Konohana-ku, Osaka 554-8558, Japan.
Kayo
K
Sumida
Preclinical Research Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 3-1-98 Kasugade-naka, Konohana-ku, Osaka 554-0022, Japan.
Kohei
K
Hoshino
Preclinical Research Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 3-1-98 Kasugade-naka, Konohana-ku, Osaka 554-0022, Japan.
Izuru
I
Miyawaki
Environmental Health Science Laboratory, Sumitomo Chemical Co., Ltd., 3-1-98 Kasugade-naka, Konohana-ku, Osaka 554-8558, Japan.
Koichi
K
Saito
Department of Ultrastructural Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan.
Fumikazu
F
Suto
Department of Ultrastructural Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan. Electronic address: nichino@ncnp.go.jp.
Noritaka
N
Ichinohe
D000818:Animals; D000831:Animals, Newborn; D002144:Callithrix; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism*; D002540:Cerebral Cortex / Q000254:growth & development / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D008928:Mitochondria / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D017470:Receptors, Glutamate / Q000235:genetics*; D000091042:Reelin Protein; D012697:Serine Endopeptidases / Q000378:metabolism*; D012741:Sexual Maturation; D013569:Synapses
D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D009419:Nerve Tissue Proteins; D018377:Neurotransmitter Agents; D017470:Receptors, Glutamate; D000091042:Reelin Protein; D012697:Serine Endopeptidases
G-protein coupling receptor; Glutatmate receptor; Primate; Reelin; Superoexide; Synapse formation; Synaptic pruning