Motherhood?induced gene expression in the mouse medial amygdala: Changes induced by pregnancy and lactation but not by pup stimuli

During lactation, adult female mice display aggressive responses toward male intruders, triggered by male-derived chemosensory signals. This behavior is not shown pup-sensitized virgin females sharing pup care with dams. The genetic mechanisms underlying the switch from attraction to aggression are unknown. In this work, we investigate differential gene expression in lactating expressing maternal compared medial amygdala (Me), a key neural structure integrating and hormonal information. results showed 197 genes upregulated dams, including encoding hormones such as prolactin, growth hormone, or follicle-stimulating neuropeptides galanin, oxytocin, pro-opiomelanocortin, related catecholaminergic cholinergic neurotransmission. contrast, 99 were downregulated among which find those for inhibins transcription factors of Fos early response families. set analysis revealed numerous Gene Ontology functional groups higher dams than females, regulation Jak/Stat cascade. Of note, number olfactory vomeronasal receptor was expressed Me, although without differences between virgins. For prolactin qPCR experiment comparing pup-sensitized, pup-naïve that levels both virgins, virgins showing intermediate levels. Altogether, show important changes may underlie some behavioral characterizing behavior.