title: Repetitive transcranial magnetic stimulation regulates L-type Ca(2+) channel activity inhibited by early sevoflurane exposure.
abstract: Sevoflurane might be harmful to the developing brain. Therefore, it is essential to reverse sevoflurane-induced brain injury.
  
  
  
  This study aimed to determine whether low-frequency repetitive transcranial magnetic stimulation (rTMS) can regulate L-type Ca(2+) channel activity, which is inhibited by early sevoflurane exposure.
  
  
  
  Rats were randomly divided into three groups: control, sevoflurane, and rTMS groups. A Whole-cell patch clamp technique was applied to record L-type Ca(2+) channel currents. The I-V curve, steady-state activation and inactivation curves were studied in rats of each group at different ages (1 week, 2 weeks, 3 weeks, 4 weeks and 5 weeks old).
  
  
  
  In the control group, L-type Ca(2+) channel current density significantly increased from week 2 to week 3. Compared with the control group, L-type Ca(2+) channel currents of rats in the sevoflurane group were significantly inhibited from week 1 to week 3. Activation curves of L-type Ca(2+) channel shifted significantly towards depolarization at week 1 and week 2. Moreover, steady-state inactivation curves shifted towards hyperpolarization from week 1 to week 3. Compared with the sevoflurane group, rTMS significantly increased L-type Ca(2+) channel currents at week 2 and week 3. Activation curves of L-type Ca(2+) channel significantly shifted towards hyperpolarization at week 2. Meanwhile, steady-state inactivation curves significantly shifted towards depolarization at week 2.
  
  
  
  The period between week 2 and week 3 is critical for the development of L-type Ca(2+) channels. Early sevoflurane exposure inhibits L-type Ca(2+) channel activity and rTMS can regulate L-type Ca(2+) channel activity inhibited by sevoflurane.
authors.affiliation: School of Biomedical Engineering, Tianjin Medical University, Tianjin, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Biomedical Engineering, Tianjin Medical University, Tianjin, China.
authors.forename: Huiyun
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China; Tianjin Research Institute of Anesthesiology, Tianjin, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Tang
authors.affiliation: School of Biomedical Engineering, Tianjin Medical University, Tianjin, China.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Bai
authors.affiliation: Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China; Tianjin Research Institute of Anesthesiology, Tianjin, China. Electronic address: wangguolinemail@126.com.
authors.forename: Guolin
authors.initials: G
authors.lastname: Wang
authors.affiliation: School of Biomedical Engineering, Tianjin Medical University, Tianjin, China. Electronic address: tianx@tijmu.edu.cn.
authors.forename: Xin
authors.initials: X
authors.lastname: Tian
mesh_terms: D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D000818:Animals; D056547:CA1 Region, Hippocampal / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D020746:Calcium Channels, L-Type / Q000502:physiology*; D005260:Female; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008738:Methyl Ethers / Q000008:administration & dosage*; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077149:Sevoflurane; D050781:Transcranial Magnetic Stimulation
chemical_list: D018685:Anesthetics, Inhalation; D020746:Calcium Channels, L-Type; D008738:Methyl Ethers; D000077149:Sevoflurane
keywords: Channel activity; Hippocampus; L-type ca(2+); Repetitive transcranial magnetic stimulation; Sevoflurane