Pyramidal neurons structure in hippocampal primary cultures. (a) Photomicrograph illustrating positive Thy1-Enhanced Green Fluorescent Protein (EGFP) pyramidal neurons from wild type (WT) and TgCHRNA5/A3/B4 (Tg) cultures exposed to medium alone (Control, Ct) or containing nicotine (Nic, 3.25 μm) for 48 h, Scale bar 25 μm. (b) Sholl analysis revealed reduced number dendritic complexity in neurons from Tg cultures, as compared to WT. Chronic exposure to nicotine rescued the reduced dendritic complexity in Tg cultures. In contrast, in WT cultures the same treatment reduced the dendritic arborisation. (c) Photomicrograph illustrating dendritic spines in EGFP transfected neurons from the experimental conditions indicated, Scale bar 2 μm. (d) Quantification of spines per 10 μm of dendrite length showed no differences among groups. Quantification of the number of (e) VGLUT1 and (f) VGAT puncta per 10 μm of dendrite length in cultures from the experimental conditions indicated. No differences in VGLUT1 puncta were detected among groups. Instead, VGAT puncta were reduced in Tg, as compared to WT cultures. Nicotine treatment reduced VGAT inputs only in WT but not in Tg cultures (n = 4-5 cells/culture; 3 - 4 cultures/condition from ≥ 3 experiments). *p ≤ 0.05, **p ≤ 0.01.