title: Behavioral and pharmacological investigation of anxiety and maternal responsiveness of postpartum female rats in a pup elevated plus maze.
abstract: The present study investigated the validity of a novel pup-based repeated elevated plus maze task to detect reduced anxiety and increased maternal responsiveness in postpartum female rats and explored the roles of dopamine D2, serotonin transporter and GABA/benzodiazepine receptors in the mediation of these processes. Sprague-Dawley postpartum or nulliparous female rats were tested 4 times every other day on postpartum days 4, 6 and 8 in an elevated plus maze with 4 pups or 4 pup-size erasers placed on each end of the two open arms. When tested with erasers, untreated postpartum mother rats entered the open arms proportionally more than nulliparous rats. They also tended to spend more time in the open arms, indicating reduced anxiety. When tested with pups, postpartum rats retrieved pups into the closed arms, entered the open arms and closed arms more and had a higher moving speed than nulliparous rats, indicating increased maternal responsiveness. Both haloperidol (0.1 or 0.2 mg/kg, sc) and fluoxetine (5 or 10 mg/kg, ip) dose- and time-dependently decreased the percentage of time spent in the open arms and speed, but did not affect the percentage of open arm entries. Diazepam (1.0 or 2.0 mg/kg, ip) did not affect pup retrieval, open arm time/entry in lactating rats. Thus, the percentage of open arm entries appears to be the most sensitive measure of anxiety in postpartum female rats, while speed could be used to index maternal responsiveness to pups, which are likely mediated by the dopamine D2 and serotonin transporter systems.
authors.affiliation: Key Laboratory of Cognition and Personality (Southwest University), Ministry of Education, China; Faculty of Psychology, Southwest University, Chongqing, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Key Laboratory of Cognition and Personality (Southwest University), Ministry of Education, China; Faculty of Psychology, Southwest University, Chongqing, China.
authors.forename: Jingxue
authors.initials: J
authors.lastname: Qin
authors.affiliation: Key Laboratory of Cognition and Personality (Southwest University), Ministry of Education, China; Faculty of Psychology, Southwest University, Chongqing, China.
authors.forename: Weihai
authors.initials: W
authors.lastname: Chen
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Sui
authors.affiliation: Key Laboratory of Cognition and Personality (Southwest University), Ministry of Education, China; Faculty of Psychology, Southwest University, Chongqing, China. Electronic address: chenhg@swu.edu.cn.
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE 68588-0308, USA. Electronic address: mli2@unl.edu.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000008:administration & dosage*; D001007:Anxiety; D003975:Diazepam / Q000008:administration & dosage; D065127:Dopamine D2 Receptor Antagonists / Q000008:administration & dosage; D005260:Female; D005473:Fluoxetine / Q000008:administration & dosage; D006220:Haloperidol / Q000008:administration & dosage; D008425:Maternal Behavior / Q000187:drug effects; D018782:Maze Learning / Q000187:drug effects; D009042:Motivation / Q000187:drug effects; D049590:Postpartum Period; D051381:Rats; D017207:Rats, Sprague-Dawley; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage
chemical_list: D014151:Anti-Anxiety Agents; D003975:Diazepam; D065127:Dopamine D2 Receptor Antagonists; D005473:Fluoxetine; D006220:Haloperidol; D017367:Selective Serotonin Reuptake Inhibitors
keywords: Diazepam; Elevated plus maze; Fluoxetine; Haloperidol; Maternal responsiveness; Postpartum anxiety