T-type Calcium Channel Regulation of Neural Tube Closure and EphrinA/EPHA Expression

Cell Rep. 2015 Oct 27;13(4):829-839. doi: 10.1016/j.celrep.2015.09.035. Epub 2015 Oct 17.


A major class of human birth defects arise from aberrations during neural tube closure (NTC). We report on a NTC signaling pathway requiring T-type calcium channels (TTCCs) that is conserved between primitive chordates (Ciona) and Xenopus. With loss of TTCCs, there is a failure to seal the anterior neural folds. Accompanying loss of TTCCs is an upregulation of EphrinA effectors. Ephrin signaling is known to be important in NTC, and ephrins can affect both cell adhesion and repulsion. In Ciona, ephrinA-d expression is downregulated at the end of neurulation, whereas, with loss of TTCC, ephrinA-d remains elevated. Accordingly, overexpression of ephrinA-d phenocopied TTCC loss of function, while overexpression of a dominant-negative Ephrin receptor was able to rescue NTC in a Ciona TTCC mutant. We hypothesize that signaling through TTCCs is necessary for proper anterior NTC through downregulation of ephrins, and possibly elimination of a repulsive signal.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Calcium Channels, T-Type / genetics
  • Calcium Channels, T-Type / metabolism*
  • Cell Adhesion / genetics
  • Cell Adhesion / physiology
  • Chordata
  • Ephrins / genetics
  • Ephrins / metabolism*
  • Neural Tube / cytology
  • Neural Tube / metabolism*
  • Signal Transduction / genetics
  • Signal Transduction / physiology
  • Xenopus


  • Calcium Channels, T-Type
  • Ephrins