Fig. 7: An intrinsic GABAergic circuit within the subregions of the LS regulates aggression in female Wistar rats.

a–d Example average z-projects showing pERK (Alexa594) immunostaining in Venus-VGAT females after exposure to the female intruder test (FIT). a dorsal LS (dLS) of a group-housed (GH), i.e., low-aggressive female, b dLS of an isolated and trained (IST), i.e., high-aggressive female, c ventral LS (vLS) of a GH female, d vLS of an IST female (LV lateral ventricle, VGAT vesicular GABA transporter). e–h Neuronal activity in the LS reflected by pERK staining after FIT exposure: e In the dLS of IST females less pERK-positive cells (two-tailed Student’s t test t₍₉₎ = 4.20, p = 0.0023) and fewer pERK/VGAT co-localized cells were found (t₍₉₎ = 3.75, p = 0.004). f Aggression negatively correlated with the number of pERK/VGAT-positive cells in the dLS (Pearson’s correlation r = −0.746, p = 0.008). g In the vLS of IST females a tendency of more pERK-positive cells (t₍₉₎ = 2.07, p = 0.068) and a higher number of pERK/VGAT-positive cells was found (T₍₉₎ = 2.28, p = 0.049). h Aggression did not correlate with the number of pERK/VGAT-positive cells in the vLS (r = 0.4915, p = 0.1247). i Infusion of muscimol (10 ng/0.5 µl) into the dLS increased total aggression (t₍₁₂₎ = 2.52, p = 0.027) and threat (Mann–Whitney U test U = 5.00, p = 0.011) in GH rats. j Inhibition of the dLS also enhanced the percentage of rats showing attacks (Fisher exact test, p < 0.0001). k Muscimol in the vLS decreased total aggression (t₍₁₃₎ = 3.191, p = 0.0071) and tended to decrease threat behavior (t₍₁₃₎ = 1.832, p = 0.090). l Inhibition of the vLS also reduced the percentage of rats showing attacks (p < 0.0001). Data are shown as mean+SEM. ^#p < 0.05, ^##p < 0.01 vs GH^{; *}p < 0.05, ^**p < 0.01^{, ***}p < 0.0001 vs vehicle. Neural activity: GH n = 6 and IST n = 5; muscimol: dLS: n = 7 vLS: n = 8 and 7.