Cellular and Molecular Neurobiology
Author: Javier Hernán Fotti | email: jfotti@fmed.uba.ar
Javier Hernán Fotti 1°, Paola Mattei 1°, Ana Paula Sieben Samek 1°, Agostina Stahl 1°, Juan Emilio Belforte 1°, Germán La Iacona 1°, Valeria Della Maggiore 1°, Lorena Rela 1°
1° Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Universidad de Buenos Aires y CONICET
Experience-dependent plasticity of neural circuits involves remodeling of glial cells in addition to neuronal structures. Astrocytes become hypertrophic and more closely associated with synapses after exposing animals to stimuli that promote synaptic plasticity. Most behavioral paradigms assessing experience-dependent astrocytic structural plasticity involve several days. Here we aimed at investigating whether astrocytic structural plasticity occurs after a short-lasting learning paradigm. For this, we trained two groups of mice in an accelerated or constant speed rotarod task (learning group and active control, respectively) and sacrificed them 24 hs post-training. Then, we immunostained brain sections for GFAP and S100B to assess morphological changes in astrocytes of different brain regions. Our results show an increased GFAP staining intensity in the hippocampus of the learning group when compared to the active control group (28±3 versus 20±3 AU, t-test, p=0.0492), as well as a tendency to a greater complexity, evaluated by sholl analysis (17% increase in median critical value, Mann-Whitney, p=0.0666). Furthermore, a significant astrocytic soma volume reduction was observed in the learning group, when compared to the active control group (46% reduction, Mann-Whitney, p=0.0208). These data indicate that astrocytic structural plasticity can be observed shortly after learning and support the hypothesis that astrocytes contribute to learning-induced synaptic plasticity.