Ontogeny of the neutral amino acid transporter SAT1/ATA1 in rat brain.
The glutamine-glutamate/GABA cycle is critical for the developing brain as glutamatergic neurotransmission is important for neuronal survival and drives synaptogenesis and activity-dependent synaptic plasticity. GABAergic transmission may be essential for the formation of neural circuits. Recently a cDNA encoding a brain-enriched System A transporter (SAT1/ATA1), has been identified which may provide glutamine to neurons for the biosynthesis of neurotransmitters glutamate and gamma-aminobutyric acid (GABA). In this study, we have examined the developmental expression pattern of SAT1/ATA1 protein in rat brain by immunohistochemistry. We find that SAT1/ATA1 was present in the developing rat brain at all gestational ages examined including prenatal days 17 and 19 and postnatal days 2, 10, 14, and adult. SAT1/ATA1 immunoreactivity was seen in the neocortex, hippocampus, and neuroepithelium at the earliest time point examined, prenatal day 17. SAT1/ATA1 was prominent in the striatum, the hippocampus and the cortex in the postnatal animals. In adults, SAT1/ATA1 was limited to the cell body region while in developing animals SAT1/ATA1 protein was found in neuronal processes. These results contribute to our understanding of the relationship between the cycling of glutamate and glutamine between astrocytes and glia and the pathophysiological conditions that occur in hypoxic ischemic encephalopathy.
Weiss
Michael D
MD
Department of Pediatrics, PO Box 100296, University of Florida, Gainesville, FL 32610-0296, USA. weissmd@peds.ufl.edu
Derazi
Shag
S
Rossignol
Candace
C
Varoqui
Helene
H
Erickson
Jeffrey D
JD
Kilberg
Michael S
MS
Anderson
Kevin J
KJ
D026924:Amino Acid Transport System A / Q000096:biosynthesis / Q000235:genetics*; D026921:Amino Acid Transport Systems, Neutral; D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000196:embryology* / Q000378:metabolism*; D004622:Embryo, Mammalian; D018507:Gene Expression Regulation, Developmental; D018698:Glutamic Acid / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D015151:Immunoblotting; D007150:Immunohistochemistry; D026901:Membrane Transport Proteins / Q000096:biosynthesis / Q000235:genetics; D009474:Neurons / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D026924:Amino Acid Transport System A; D026921:Amino Acid Transport Systems, Neutral; D026901:Membrane Transport Proteins; C486716:Slc38a1 protein, rat; C403222:system N protein 1; D005973:Glutamine; D018698:Glutamic Acid