title: Effects of repeated pup exposure on behavioral, neural, and adrenocortical responses to pups in male California mice (Peromyscus californicus).
abstract: In biparental mammals, the factors facilitating the onset of male parental behavior are not well understood. While hormonal changes in fathers may play a role, prior experience with pups has also been implicated. We evaluated effects of prior exposure to pups on paternal responsiveness in the biparental California mouse (Peromyscus californicus). We analyzed behavioral, neural, and corticosterone responses to pups in adult virgin males that were interacting with a pup for the first time, adult virgin males that had been exposed to pups 3 times for 20min each in the previous week, and new fathers. Control groups of virgins were similarly tested with a novel object (marble). Previous exposure to pups decreased virgins' latency to approach pups and initiate paternal care, and increased time spent in paternal care. Responses to pups did not differ between virgins with repeated exposure to pups and new fathers. In contrast, repeated exposure to a marble had no effects. Neither basal corticosterone levels nor corticosterone levels following acute pup or marble exposure differed among groups. Finally, Fos expression in the medial preoptic area, ventral and dorsal bed nucleus of the stria terminalis was higher following exposure to a pup than to a marble. Fos expression was not, however, affected by previous exposure to these stimuli. These results suggest that previous experience with pups can facilitate the onset of parental behavior in male California mice, similar to findings in female rodents, and that this effect is not associated with a general reduction in neophobia.
authors.affiliation: Graduate Program in Neuroscience, University of California, Riverside, United States; Department of Biology, University of California, Riverside, United States.
authors.forename: Nathan D
authors.initials: ND
authors.lastname: Horrell
authors.affiliation: Department of Biology, University of California, Riverside, United States; Evolution, Ecology, and Organismal Biology Graduate Program, University of California, Riverside, United States.
authors.forename: Juan P
authors.initials: JP
authors.lastname: Perea-Rodriguez
authors.affiliation: Department of Biological Sciences, Texas Tech University, United States.
authors.forename: Breanna N
authors.initials: BN
authors.lastname: Harris
authors.affiliation: Graduate Program in Neuroscience, University of California, Riverside, United States; Department of Biology, University of California, Riverside, United States; Evolution, Ecology, and Organismal Biology Graduate Program, University of California, Riverside, United States. Electronic address: Saltzman@ucr.edu.
authors.forename: Wendy
authors.initials: W
authors.lastname: Saltzman
mesh_terms: D000302:Adrenal Cortex / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal / Q000502:physiology; D059333:Central Nervous System Sensitization / Q000502:physiology*; D003345:Corticosterone / Q000378:metabolism*; D005220:Fathers / Q000523:psychology*; D005260:Female; D008297:Male; D009425:Nesting Behavior / Q000502:physiology*; D010332:Paternal Behavior / Q000502:physiology*; D010542:Peromyscus / Q000378:metabolism / Q000502:physiology / Q000523:psychology; D011301:Preoptic Area / Q000502:physiology; D012919:Social Behavior
chemical_list: D003345:Corticosterone
keywords: Bed nucleus of the stria terminalis; Biparental; California mouse; Corticosterone; Medial preoptic area; Parental care; Paternal care; Peromyscus californicus; Sensitization