title: Fostering itself increases nicotine self-administration in young adult male rats.
abstract: BACKGROUND
  In gestational exposure studies, a fostered group is frequently used to control for drug-induced maternal effects. However, fostering itself has varying effects depending on the parameters under investigation
  
  
  OBJECTIVE
  This study was designed to assess whether maternal behavior contributed to enhanced acquisition (higher number of bar presses compared to controls) of nicotine self-administration (SA) displayed by offspring with gestational nicotine and ethanol (Nic+EtOH) exposure.
  
  
  METHODS
  Offspring were exposed to Nic+EtOH throughout full gestation, that is, gestational days (GD) GD2-20 and during postnatal days 2-12 (PN2-12), the rodent third trimester equivalent of human gestation during which rapid brain growth and synaptogenesis occur. Young adult (PN60) male offspring acquired operant nicotine SA, using a model of unlimited (i.e., 23 h) access to nicotine.
  
  
  RESULTS
  Gestational drug treatments did not alter litter parameters (body weight, volume distribution, crown-rump length, and brain weight) or postnatal growth of the offspring. Fostering increased locomotor activity to a novel environment on PN45 regardless of gestational treatment group. Surprisingly, fostering per se significantly increased the SA behavior of drug-naïve pair-fed controls, so that their drug-taking behavior resembled the enhanced nicotine SA observed in non-fostered offspring exposed to Nic+EtOH during gestation. In contrast, fostering did not change the SA behavior of the Nic+EtOH group.
  
  
  CONCLUSIONS
  Fostering is shown to be its own experimental variable, ultimately increasing the acquisition of nicotine SA in control, drug-naïve offspring. As such, the current dogma that fostering is required for our gestationally drug-exposed offspring is contraindicated.
authors.affiliation: Department of Pharmacology, University of Tennessee Health Science Center, 115 Crowe Research Building, 874 Union Ave., Memphis, TN 38163, USA. eroguski@uthsc.edu
authors.forename: Emily E
authors.initials: EE
authors.lastname: Roguski
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.forename: Burt M
authors.initials: BM
authors.lastname: Sharp
authors.forename: Shannon G
authors.initials: SG
authors.lastname: Matta
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D002492:Central Nervous System Depressants / Q000009:adverse effects*; D000431:Ethanol / Q000009:adverse effects*; D005260:Female; D005581:Foster Home Care; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009538:Nicotine / Q000008:administration & dosage / Q000009:adverse effects; D018722:Nicotinic Agonists / Q000008:administration & dosage* / Q000009:adverse effects; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012646:Self Administration
chemical_list: D002492:Central Nervous System Depressants; D018722:Nicotinic Agonists; D000431:Ethanol; D009538:Nicotine