Short Communication Ethanol prevents NMDA receptor reduction by maternal separation in neonatal rat hippocampus Frederick P. Bellinger ⁎ , Mark S. Davidson, Kuldip S. Bedi 1 , Peter A. Wilce University of Queensland, Brisbane, QLD 4072, Australia ARTICLE INFO ABSTRACT Article history: Accepted 29 September 2005 Available online 15 December 2005 We measured the effects of ethanol on glutamate receptor levels in the hippocampus of neonatal Wistar rats using a vapor chamber model. Two control groups were used; a normal suckle group and a maternal separation group. Levels of NMDA receptors were not significantly altered in ethanol-treated animals compared to the normal suckle control group, as shown by [ 3 H]MK-801 binding and Western blot analysis. However, MK-801 binding and NR1 subunit immunoreactivity were greatly reduced in the hippocampus of separation control animals. Neither ethanol treatment nor maternal separation altered levels of GluR1 or GluR2(4). These results have serious implications for the importance of maternal contact for normal brain development. © 2005 Elsevier B.V. All rights reserved. Theme: Disorders of the nervous system Topic: Developmental disorders Keywords: Fetal alcohol syndrome FAS AMPA receptor MK-801 Fetal alcohol syndrome (FAS) is the term for a pattern of physiological and psychological impairments resulting from ethanol consumption during pregnancy (Clarren and Smith, 1978). One model used for third trimester ethanol adminis- tration uses an ethanol vapor chamber (Davidson et al., 1998). This model is less invasive than other models such as artificial rearing (Ryabinin et al., 1995). However, as neonatal animals must be separated from their mothers during ethanol administration, a separation control group must be used. This is problematic as many studies indicate impairments arising in neonatal animals from maternal separation (Leh- mann and Feldon, 2000). In this report, we look at the effects of ethanol and maternal separation on glutamate receptor expression in the hippocampus. Prior approval for all procedures was obtained from the UQ Animal Experimentation Ethics Committee (AEEC). Litters of Wistar rats with dams were obtained from the Central Animal Breeding House, University of Queensland, at postnatal day (PND) 1–2. Neonatal rat litters were “scrambled” into random groups and returned to mothers, with no more than 8 animals/ litter. Animals were raised in a normal light/dark cycle at 20 °C with food and water given to mothers ad libitum. From PND 4– 9, pups were removed from mothers and placed in an ethanol vapor chamber described previously (Bellinger et al., 1999; Davidson et al., 1998). Exposure to 40–50 mg/L ethanol vapor for 3 h each day resulted in blood alcohol levels of 343 ± 34 mg/ dL, consistent with previous findings (Bellinger et al., 1999, 2002; Davidson et al., 1998). Separation control animals were BRAIN RESEARCH 1067 (2006) 154 – 157 ⁎ Corresponding author. University of Hawaii, Honolulu, HI 96822, USA. E-mail address: rikkugon@pbrc.hawaii.edu (F.P. Bellinger). 1 Current address: Bold University, Gold Coast, QLD 4229, Australia. 0006-8993/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.brainres.2005.09.067 available at www.sciencedirect.com www.elsevier.com/locate/brainres