Figure 4. Ablation of aromatase+ MeApd neurons reduces specific components of maternal aggression.
(A) Experimental strategy to ablate Cre-expressing aromatase+ MeApd neurons and test for behavioral deficits. AAV encoding Cre-dependent caspase-3 was injected into the MeA of separate cohorts of aroCre/IPIN and aro+/IPIN females for testing performance in mating and maternal behaviors.
(B) No difference in fraction of mounts that were accepted or rejected and no difference in receptivity index (# intromissions/# mounts) between aroCre/IPIN and aro+/IPIN females.
(C) Vast majority of aroCre/IPIN and aro+/IPIN females retrieved all pups to the nest, and they did so with similar latencies.
(D) Comparable percent of aroCre/IPIN and aro+/IPIN females sniff and attack a WT intruder male. Significant decrease in number of attacks directed to intruder male by aroCre/IPIN females.
(E) A WT male intruder was inserted into the cage of a resident male or lactating female for 15 min. Mothers have a longer latency to sniff the intruder and, unlike resident males, can attack the intruder prior to chemoinvestigation. The duration of individual attacks as well as total duration of attacks initiated by mothers is significantly shorter. Mothers spend significantly less time chasing or wrestling with the intruder male. No boxing was observed in attacks initiated by mothers. Mothers bite the intruder significantly more on the head or anogenital region compared to resident males. Resident males bite the intruder significantly more on the back and flank compared to mothers. Data for these behavioral comparisons is taken from animals used to generate data for panels in Figures 2C, 4D, S1B, and S4D.
Mean ± SEM; n > 14 aro+/IPIN and n > 7 aroCre/IPIN for tests of sexual and maternal behaviors each (A–D); n = 7 aro+/IPIN males and 6 aro+/IPIN mothers (E); *p < 0.05, **p < 0.01, ***p < 0.005; OVX, ovaries surgically removed. See also Figure S4.