Fig. 6

Absence of microgliosis and preserved response to stimuli of hippocampal microglia from VPA animal. a CA3 hippocampal region from control and VPA animals immunostained for Iba1. At PND3, qualitative analysis of microglia showed a similar immunostaining pattern in both groups. At PND35, b Iba1 relative immunoreactive area and c number of Iba1 (+) cells were conserved in the VPA group. d Cell schematic representation shows microglia morphology classification employed. No statistical differences were observed between groups when number of ramified and unramified cells was counted related to total number of Iba1 (+) cells. e Microglia isolated from VPA animals and cultured in the absence of neurons showed preserved size and internal complexity when analyzed by flow cytometry. f Representation of cell morphology in culture and its associated circularity, indicative of cell reactivity. g Hippocampal microglia cultures isolated from control and VPA animals and immunolabeled for Iba1 in basal conditions and after LPS stimulus. h Similar reactivity profile (circularity values) was observed in both groups in basal conditions; both groups responded to LPS by increasing its circularity i with no changes in average cell area. j Cultured hippocampal microglia isolated from control and VPA animals and immunolabeled for Iba1 in basal conditions and after exposure to hippocampal synaptosomes (ST). k No statistical changes in circularity were observed after exposure to ST in control and VPA groups. l After ST exposure, microglial cells from both experimental groups responded by decreasing the average cell area. Results are expressed as mean values (± SD; b–d control n = 4–5 animals, VPA n = 5–6 animals; e a representative experiment run by triplicate; h–l 30–35 photomicrographs per group from two independent cultures). b–e: ns: non-significant between bars by Student’s t test; h–l ns: non-significant; #p < 0.05; ##p < 0.01 between groups by Kruskal–Wallis Test. Scale bar: 50 µm. pyr: soma of CA3 pyramidal neurons