Maternal aggression: new insights from Egr-1.
Lactating mice display fierce aggression towards novel, male mice. This study compares neuronal activity in the brains of aggression-tested (T) and -untested (U) mice using early growth response factor 1 (Egr-1; also known as Krox 24, NGFI-A, Zif268, Tis8, and ZENK) as a measure of neuronal activity. Animals were sampled 90 min after either a sham or real 7-min test with a male intruder, after which their brains were examined for immunoreactivity to Egr-1 (Egr-IR). Significant increases in Egr-IR in T mice were identified in 11 of 40 brain regions, including paraventricular nucleus of the hypothalamus; anterior and lateral hypothalamus (both posterior portion); ventromedial hypothalamus; lateral periaqueductal gray; and medial, central, and basolateral amygdala. Posterodorsal (MePD) and posteroventral medial amygdala were examined for the first time in association with maternal aggression. MePD, a region associated with both sexual and aggressive behaviors in rats, hamsters, and mice, showed increased Egr-IR in association with testing. Taken together, the results from this study provide new insights into the neural circuits regulating maternal behaviors.
Hasen
Nina S
NS
Department of Zoology, University of Wisconsin, Madison, 53706, USA. nshasen@wisc.edu
Gammie
Stephen C
SC
D000374:Aggression / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D051766:Early Growth Response Protein 1 / Q000378:metabolism*; D005260:Female; D008297:Male; D008425:Maternal Behavior / Q000502:physiology*; D051379:Mice; D009434:Neural Pathways / Q000033:anatomy & histology / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D012726:Sexual Behavior, Animal / Q000502:physiology
D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; D016760:Proto-Oncogene Proteins c-fos