PMID- 25638314 OWN - NLM STAT- MEDLINE DCOM- 20160104 LR - 20191210 IS - 1879-291X (Electronic) IS - 0301-5629 (Linking) VI - 41 IP - 3 DP - 2015 Mar TI - Prenatal exposure to ultrasound affects learning and memory in young rats. PG - 644-53 LID - S0301-5629(14)00612-7 [pii] LID - 10.1016/j.ultrasmedbio.2014.09.015 [doi] AB - Prenatal exposure to ultrasound may cause cognitive impairments in experimental animals; however, the exact mechanisms remain unknown. In this study, we exposed pregnant rats (or sham-exposed controls) to different intensities of ultrasound repeatedly on days 6, 12 and 18 of pregnancy for 4 min (3.5 MHz, spatial peak time average intensity = 7.6 mW/cm(2), mechanical index = 0.1, thermal index bone = 0.1: 4-min group) or 20 min (3.5 MHz, spatial peak time average intensity = 106 mW/cm(2), mechanical index = 1.4, thermal index bone = 1.0: 20-min group). The Morris water maze was used to assess learning and memory function in pups at 2 mo of age. Noticeable deficits in behavior occurred in the group exposed to ultrasound for 20 min. Using real-time polymerase chain reaction and Western blot, we also determined that both the mRNA and protein expression levels of hippocampal N-methyl-D-aspartate (NMDA) receptor units 1 (NR1) and 2B (NR2B) and brain-derived neurotrophic factor (BDNF) were significantly lower in pups exposed to ultrasound for 20 min than in controls. Furthermore, the morphology of the synapses in the hippocampus was partially damaged. Compared with the control group, the 4-min group had better spatial learning and memory abilities, as well as higher mRNA and protein levels of NR1, NR2B and BDNF. Our study suggests that high-intensity ultrasound irradiation can decrease learning and memory abilities by reducing the expression of NR1, NR2B and BDNF in the hippocampal regions and damaging the structure of synapses. In contrast, low-intensity ultrasound irradiation can enhance the learning and memory abilities of the offspring rats by increasing the expression of NR1, NR2B and BDNF receptor in the hippocampal regions. CI - Copyright (c) 2015 World Federation for Ultrasound in Medicine & Biology. All rights reserved. FAU - Li, Ping AU - Li P AD - Department of Ultrasound, Tongji Hospital, Medical School of Tongji University, Putuo District, Shanghai, China. FAU - Wang, Pei-Jun AU - Wang PJ AD - Department of Ultrasound, Tongji Hospital, Medical School of Tongji University, Putuo District, Shanghai, China. Electronic address: wangpeijun_918@126.com. FAU - Zhang, Wei AU - Zhang W AD - Department of Ultrasound, Tongji Hospital, Medical School of Tongji University, Putuo District, Shanghai, China. LA - eng PT - Journal Article DEP - 20150128 PL - England TA - Ultrasound Med Biol JT - Ultrasound in medicine & biology JID - 0410553 RN - 0 (Brain-Derived Neurotrophic Factor) RN - 0 (NMDA receptor A1) RN - 0 (NR2B NMDA receptor) RN - 0 (Receptors, N-Methyl-D-Aspartate) SB - IM EIN - Ultrasound Med Biol. 2015 Oct;41(10):2784 MH - Animals MH - Blotting, Western MH - Brain-Derived Neurotrophic Factor/metabolism MH - Female MH - Hippocampus/metabolism MH - Humans MH - Infant, Newborn MH - Learning Disabilities/*etiology MH - Male MH - Maze Learning MH - Memory Disorders/*etiology MH - Pregnancy MH - *Prenatal Exposure Delayed Effects MH - Rats MH - Rats, Sprague-Dawley MH - Real-Time Polymerase Chain Reaction MH - Receptors, N-Methyl-D-Aspartate/metabolism MH - Ultrasonography, Prenatal/*adverse effects OTO - NOTNLM OT - Brain-derived neurotrophic factor OT - Hippocampus OT - Learning and memory OT - Morris water maze OT - N-methyl-D-aspartate OT - Receptor OT - Synapses OT - Ultrasound EDAT- 2015/02/02 06:00 MHDA- 2016/01/05 06:00 CRDT- 2015/02/02 06:00 PHST- 2014/02/09 00:00 [received] PHST- 2014/08/23 00:00 [revised] PHST- 2014/09/02 00:00 [accepted] PHST- 2015/02/02 06:00 [entrez] PHST- 2015/02/02 06:00 [pubmed] PHST- 2016/01/05 06:00 [medline] AID - S0301-5629(14)00612-7 [pii] AID - 10.1016/j.ultrasmedbio.2014.09.015 [doi] PST - ppublish SO - Ultrasound Med Biol. 2015 Mar;41(3):644-53. doi: 10.1016/j.ultrasmedbio.2014.09.015. Epub 2015 Jan 28.