Although the role of hippocampus in memory processing is well assessed, an association of experience-dependent behavioural modifications with hippocampal neuron morphological and biochemical changes deserves further characterisation. Here, we present evidence of dendritic alterations together with rapid accumulation of EphrinB2, a factor known to influence cell plasticity, in pyramidal neurons of the CA1 area of mouse hippocampus, during the formation of recent contextual fear memory. Male C57BL/6N mice exhibited a robust fear response 24 h after contextual and cued fear conditioning. At this time and in the absence of the memory test, conditioned mice showed morphological alterations in hippocampal and lateral amygdala neurons. Western blot analysis of extracts from conditioned but not pseudoconditioned or naive mice showed a specific increase in the amount of EphrinB2 in the hippocampus but not the cortex. However, levels of EphA4 receptor, known to interact trans-synaptically with EphrinB2, did not change upon conditioning in extracts from the same structures. Finally, immunohistochemical analysis of the hippocampus and amygdala of conditioned mice showed increased levels of EphrinB2 in pyramidal neurons of the CM area, when compared to pseudoconditioned and control mice. Such increase was not observed in other hippocampal areas or the amygdala. These results suggest that rapid accumulation of EphrinB2 in hippocampal CA1 neurons is involved in the behavioural and cellular modifications induced by contextual fear conditioning. A similar mechanism does not appear to occur in lateral amygdala neurons, in spite of the robust behavioural and cellular modifications induced in such structure by cued fear conditioning. (C) 2011 Elsevier B.V. All rights reserved.

Contextual learning increases dendrite complexity and EphrinB2 levels in hippocampal mouse neurons / Trabalza, Antonio; Colazingari, Sandra; Carmelo, Sgobio; Bevilacqua, Arturo. - In: BEHAVIOURAL BRAIN RESEARCH. - ISSN 0166-4328. - STAMPA. - 227:1(2012), pp. 175-183. [10.1016/j.bbr.2011.11.008]

Contextual learning increases dendrite complexity and EphrinB2 levels in hippocampal mouse neurons

TRABALZA, ANTONIO;COLAZINGARI, SANDRA;BEVILACQUA, Arturo
2012

Abstract

Although the role of hippocampus in memory processing is well assessed, an association of experience-dependent behavioural modifications with hippocampal neuron morphological and biochemical changes deserves further characterisation. Here, we present evidence of dendritic alterations together with rapid accumulation of EphrinB2, a factor known to influence cell plasticity, in pyramidal neurons of the CA1 area of mouse hippocampus, during the formation of recent contextual fear memory. Male C57BL/6N mice exhibited a robust fear response 24 h after contextual and cued fear conditioning. At this time and in the absence of the memory test, conditioned mice showed morphological alterations in hippocampal and lateral amygdala neurons. Western blot analysis of extracts from conditioned but not pseudoconditioned or naive mice showed a specific increase in the amount of EphrinB2 in the hippocampus but not the cortex. However, levels of EphA4 receptor, known to interact trans-synaptically with EphrinB2, did not change upon conditioning in extracts from the same structures. Finally, immunohistochemical analysis of the hippocampus and amygdala of conditioned mice showed increased levels of EphrinB2 in pyramidal neurons of the CM area, when compared to pseudoconditioned and control mice. Such increase was not observed in other hippocampal areas or the amygdala. These results suggest that rapid accumulation of EphrinB2 in hippocampal CA1 neurons is involved in the behavioural and cellular modifications induced by contextual fear conditioning. A similar mechanism does not appear to occur in lateral amygdala neurons, in spite of the robust behavioural and cellular modifications induced in such structure by cued fear conditioning. (C) 2011 Elsevier B.V. All rights reserved.
2012
amygdala; cued fear conditioning; mouse; contextual fear conditioning; dendritic spines; dendritic nodes; pyramidal neurons; ephrinb2; hippocampus; fear conditioning
01 Pubblicazione su rivista::01a Articolo in rivista
Contextual learning increases dendrite complexity and EphrinB2 levels in hippocampal mouse neurons / Trabalza, Antonio; Colazingari, Sandra; Carmelo, Sgobio; Bevilacqua, Arturo. - In: BEHAVIOURAL BRAIN RESEARCH. - ISSN 0166-4328. - STAMPA. - 227:1(2012), pp. 175-183. [10.1016/j.bbr.2011.11.008]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/378994
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