1: Eur J Neurosci. 2003 Sep;18(5):1265-78. 

Erratum in:
    Eur J Neurosci. 2003 Sep;18(6):1717.

Plasma membrane and vesicular glutamate transporter mRNAs/proteins in
hypothalamic neurons that regulate body weight.

Collin M, Backberg M, Ovesjo ML, Fisone G, Edwards RH, Fujiyama F, Meister B.

Department of Neuroscience, Karolinska Institutet, Retzius vag 8, B3, 5th Floor,
Room 514, SE-171 77 Stockholm, Sweden.

After synaptic release, glutamate is taken up by the nerve terminal via a plasma
membrane-associated protein termed excitatory amino acid transporter 3 (EAAT3).
Following entry into the nerve terminal, glutamate is pumped into synaptic
vesicles by a vesicular transport system. Three different vesicular glutamate
transporter proteins (VGLUT1-3) representing unique markers for glutamatergic
neurons were recently characterized. The presence of EAAT3, glutaminase and
VGLUT1-3 was examined in mouse, rat and rabbit species at mRNA and protein
levels in hypothalamic neurons which are involved in the regulation of body
weight using in situ hybridization and immunohistochemistry. EAAT3 and
glutaminase mRNAs were demonstrated in all parts of the arcuate nucleus in the
dorsomedial and ventromedial hypothalamic nuclei and lateral hypothalamic area.
VGLUT1 mRNA was present in the magnocellular lateral hypothalamic nucleus.
VGLUT2 mRNA was demonstrated in a subpopulation of neurons in the arcuate
nucleus and in the ventromedial and dorsomedial hypothalamic nuclei and lateral
hypothalamic area. Few VGLUT3 mRNA expressing neurons were scattered throughout
the medial and lateral hypothalamus. EAAT3-like immunoreactivity (-li) was
demonstrated in glutamate, neuropeptide Y (NPY), agouti-related peptide (AGRP),
pro-opiomelanocortin (POMC), cocaine and amphetamine-regulated transcript
(CART), melanin-concentrating hormone and orexin-immunoreactive (-ir) neurons.
VGLUT2-li could only be demonstrated in POMC- and CART-ir neurons of the
ventrolateral arcuate nucleus. The results show that key neurons involved in
regulation of energy balance are glutamatergic and/or densely innervated by
glutamatergic nerve terminals. Whereas orexigenic NPY/AGRP neurons situated in
the ventromedial part of the arcuate nucleus are mainly GABAergic, it is shown
that several anorexigenic POMC/CART neurons of the ventromedial arcuate nucleus
are most likely glutamatergic [corrected].

PMID: 12956725 [PubMed - indexed for MEDLINE]


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