caa a22 4500 606202056 CHVBK 20210128100951.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00429-014-0722-z doi (NATIONALLICENCE)springer-10.1007/s00429-014-0722-z Distinct and simultaneously active plasticity mechanisms in mouse hippocampus during different phases of Morris water maze training [Elektronische Daten] [Annelies Laeremans, Victor Sabanov, Tariq Ahmed, Julie Nys, Babs Van de Plas, Kasper Vinken, Daniel Woolley, Ilse Gantois, Rudi D'Hooge, Lutgarde Arckens, Detlef Balschun] Although the Morris water maze (MWM) is the most frequently used protocol to examine hippocampus-dependent learning in mice, not much is known about the spatio-temporal dynamics of underlying plasticity processes. Here, we studied molecular and cellular hippocampal plasticity mechanisms during early and late phases of spatial learning in the MWM. Quantitative in situ hybridization for the immediate early genes zif268 and Homer1a (H1a) revealed phase-dependent differences in their expression between areas CA1 and CA3. During the initial learning phase, CA1 expression levels of the molecular plasticity marker H1a, but not of the activity reporter gene zif268, were related to task proficiency; whereas no learning-specific changes could be detected in CA3. Simultaneously, the ratio of surface-expressed NMDAR subunits NR2A and NR2B was downregulated as measured by acute slice biotinylation assay, while the total number of surface NMDARs was unaltered. When intrinsic ‘somatic' and synaptic plasticity in the CA1-region of hippocampal slices were examined, we found that early learning promotes intrinsic neuronal plasticity as manifested by a reduction of spike frequency adaptation and postburst afterhyperpolarization. At the synaptic level, however, maintenance of long-term potentiation (LTP) in all learning groups was impaired which is most likely due to ‘intrinsic' learning-induced LTP which occluded any further electrically induced LTP. Late learning, in contrast, was characterized by re-normalized H1a, NR2A and NR2B expression and neuronal firing, yet a further strengthening of learning-induced LTP. Together, our data support a precisely timed cascade of complex molecular and subcellular transformations occurring from early to late MWM learning. Springer-Verlag Berlin Heidelberg, 2014 Hippocampus nationallicence IEGs nationallicence Electrophysiology nationallicence NMDAR subunits nationallicence Synaptic plasticity nationallicence LTP nationallicence Laeremans Annelies Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Naamsestraat 59, 3000, Leuven, Belgium aut Sabanov Victor Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium aut Ahmed Tariq Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium aut Nys Julie Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Naamsestraat 59, 3000, Leuven, Belgium aut Van de Plas Babs Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Naamsestraat 59, 3000, Leuven, Belgium aut Vinken Kasper Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium aut Woolley Daniel Laboratory of Movement Control and Neuroplasticity, KU Leuven, Tervuursevest 101, 3001, Heverlee, Belgium aut Gantois Ilse Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium aut D'Hooge Rudi Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium aut Arckens Lutgarde Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Naamsestraat 59, 3000, Leuven, Belgium aut Balschun Detlef Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium aut Brain Structure and Function Springer Berlin Heidelberg 220/3(2015-05-01), 1273-1290 1863-2653 220:3<1273 2015 220 429 https://doi.org/10.1007/s00429-014-0722-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00429-014-0722-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Laeremans Annelies Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Naamsestraat 59, 3000, Leuven, Belgium aut NATIONALLICENCE 700 1- Sabanov Victor Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium aut NATIONALLICENCE 700 1- Ahmed Tariq Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium aut NATIONALLICENCE 700 1- Nys Julie Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Naamsestraat 59, 3000, Leuven, Belgium aut NATIONALLICENCE 700 1- Van de Plas Babs Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Naamsestraat 59, 3000, Leuven, Belgium aut NATIONALLICENCE 700 1- Vinken Kasper Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium aut NATIONALLICENCE 700 1- Woolley Daniel Laboratory of Movement Control and Neuroplasticity, KU Leuven, Tervuursevest 101, 3001, Heverlee, Belgium aut NATIONALLICENCE 700 1- Gantois Ilse Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium aut NATIONALLICENCE 700 1- D'Hooge Rudi Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium aut NATIONALLICENCE 700 1- Arckens Lutgarde Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Naamsestraat 59, 3000, Leuven, Belgium aut NATIONALLICENCE 700 1- Balschun Detlef Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium aut NATIONALLICENCE 773 0- Brain Structure and Function Springer Berlin Heidelberg 220/3(2015-05-01), 1273-1290 1863-2653 220:3<1273 2015 220 429