Vesicular glutamate transporter VGLUT1 has a role in hippocampal long-term potentiation and spatial reversal learning.
Vesicular glutamate transporters 1 and 2 (VGLUT1, VGLUT2) show largely complementary distribution in the mature rodent brain and tend to segregate to synapses with different physiological properties. In the hippocampus, VGLUT1 is the dominate subtype in adult animals, whereas VGLUT2 is transiently expressed during early postnatal development. We generated and characterized VGLUT1 knockout mice in order to examine the functional contribution of this transporter to hippocampal synaptic plasticity and hippocampus-dependent spatial learning. Because complete deletion of VGLUT1 resulted in postnatal lethality, we used heterozygous animals for analysis. Here, we report that deletion of VGLUT1 resulted in impaired hippocampal long-term potentiation (LTP) in the CA1 region in vitro. In contrast, heterozygous VGLUT2 mice that were investigated for comparison did not show any changes in LTP. The reduced ability of VGLUT1-deficient mice to express LTP was accompanied by a specific deficit in spatial reversal learning in the water maze. Our data suggest a functional role of VGLUT1 in forms of hippocampal synaptic plasticity that are required to adapt and modify acquired spatial maps to external stimuli and changes.
Balschun
Detlef
D
Department of Psychology, Laboratory of Biological Psychology, Katholieke Universiteit Leuven, Tiensestraat 102, B-3000 Leuven, Belgium. detlef.balschun@psy.kuleuven.be
Moechars
Diederik
D
Callaerts-Vegh
Zsuzsanna
Z
Vermaercke
Ben
B
Van Acker
Nathalie
N
Andries
Luc
L
D'Hooge
Rudi
R
D000704:Analysis of Variance; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D001703:Biophysics; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism; D004558:Electric Stimulation / Q000379:methods; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D017774:Long-Term Potentiation / Q000235:genetics / Q000502:physiology*; D018782:Maze Learning / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018408:Patch-Clamp Techniques; D017966:Pyramidal Cells / Q000502:physiology; D013037:Spatial Behavior / Q000502:physiology*; D018709:Statistics, Nonparametric; D050598:Vesicular Glutamate Transport Protein 1 / Q000172:deficiency / Q000502:physiology*; D050599:Vesicular Glutamate Transport Protein 2 / Q000172:deficiency
C493477:Slc17a6 protein, mouse; C493465:Slc17a7 protein, mouse; D050598:Vesicular Glutamate Transport Protein 1; D050599:Vesicular Glutamate Transport Protein 2