PMID- 12853368
OWN - NLM
STAT- MEDLINE
DCOM- 20030903
LR  - 20190513
IS  - 1047-3211 (Print)
IS  - 1047-3211 (Linking)
VI  - 13
IP  - 8
DP  - 2003 Aug
TI  - Boutons containing vesicular zinc define a subpopulation of synapses with low 
      AMPAR content in rat hippocampus.
PG  - 823-9
AB  - Cortical regions of the brain stand out for their high content in synaptic zinc, 
      which may thus be involved in synaptic function. The relative number, chemical 
      nature and transmitter receptor profile of synapses that sequester vesicular zinc 
      are largely unknown. To address this, we combined pre-embedding zinc 
      histochemistry and post-embedding immunogold electron microscopy in rat 
      hippocampus. All giant mossy fibre (MF) terminals in the CA3 region and 
      approximately 45% of boutons making axospinous synapses in stratum radiatum in 
      CA1 contained synaptic vesicles that stained for zinc. Both types of 
      zinc-positive boutons selectively expressed the vesicular zinc transporter ZnT-3. 
      Zinc-positive boutons further immunoreacted to the vesicular glutamate 
      transporter VGLUT-1, but not to the transmitter gamma-aminobutyric acid. Most 
      dendritic spines in CA1 immunoreacted to 
      alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) 
      subunits GluR1-3 (approximately 80%) and to N-methyl-D-aspartate receptor (NMDAR) 
      subunits NR1 + NR2A/B (approximately 90%). Synapses made by zinc-positive boutons 
      contained 40% less AMPAR particles than those made by zinc-negative boutons, 
      whereas NMDAR counts were similar. Further analysis indicated that this was due 
      to the reduced synaptic expression of both GluR1 and GluR2 subunits. Hence, the 
      levels of postsynaptic AMPARs may vary according to the presence of vesicular 
      zinc in excitatory afferents to CA1. Zinc-positive and zinc-negative synapses may 
      represent two glutamatergic subpopulations with distinct synaptic signalling.
FAU - Sindreu, Carlos Balet
AU  - Sindreu CB
AD  - Departament de Biologia Cellular, Facultat de Biologia, Universitat de Barcelona, 
      ES-08071 Barcelona, Spain. carbalet@bio.ub.es
FAU - Varoqui, Helene
AU  - Varoqui H
FAU - Erickson, Jeffrey D
AU  - Erickson JD
FAU - Perez-Clausell, Jeus
AU  - Perez-Clausell J
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Cereb Cortex
JT  - Cerebral cortex (New York, N.Y. : 1991)
JID - 9110718
RN  - 0 (Receptors, AMPA)
RN  - J41CSQ7QDS (Zinc)
SB  - IM
MH  - Animals
MH  - Hippocampus/chemistry/*metabolism
MH  - Male
MH  - Presynaptic Terminals/chemistry/*metabolism
MH  - Rats
MH  - Rats, Wistar
MH  - Receptors, AMPA/*analysis/biosynthesis
MH  - Synapses/chemistry/*metabolism
MH  - Synaptic Vesicles/chemistry/*metabolism
MH  - Zinc/*analysis/physiology
EDAT- 2003/07/11 05:00
MHDA- 2003/09/04 05:00
CRDT- 2003/07/11 05:00
PHST- 2003/07/11 05:00 [pubmed]
PHST- 2003/09/04 05:00 [medline]
PHST- 2003/07/11 05:00 [entrez]
AID - 10.1093/cercor/13.8.823 [doi]
PST - ppublish
SO  - Cereb Cortex. 2003 Aug;13(8):823-9. doi: 10.1093/cercor/13.8.823.