Reorganization of pontine rhythmogenic neuronal networks in Krox-20 knockout mice

Neuron. 1996 Oct;17(4):747-58. doi: 10.1016/s0896-6273(00)80206-8.


We have shown previously that the inactivation of the zinc finger gene Krox-20 affects hindbrain segmentation, resulting in the elimination of rhombomeres 3 and 5. We demonstrate here that Krox-20 homozygous mutant mice exhibit abnormally slow respiratory and jaw opening rhythms, indicating that a modification of hindbrain segmentation influences the function of neuronal networks after birth. Central neuronal networks that control respiratory frequency are made predominantly depressant by the elimination of a previously undescribed rhythm-promoting system. Recordings of rhythmic activity from the isolated hindbrain following progressive tissue transections indicate that the reorganization takes place in the caudal pontine reticular formation. The newborn (PO) Krox-20-/- mice, in which apneas are ten times longer than in wild-type animals, may be a valuable model for the study of life-threatening apneas during early infancy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Brain Stem / physiology
  • Cerebellum / physiology
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology*
  • Early Growth Response Protein 2
  • Female
  • Humans
  • In Vitro Techniques
  • Infant, Newborn
  • Mice
  • Naloxone / pharmacology
  • Nerve Net / physiology*
  • Neurons / physiology*
  • Placenta / physiology
  • Plethysmography
  • Pons / physiology*
  • Pregnancy
  • Respiration / drug effects
  • Respiration / physiology
  • Respiratory Distress Syndrome, Newborn
  • Spinal Cord / physiology
  • Transcription Factors / genetics
  • Transcription Factors / physiology*
  • Yolk Sac / physiology
  • Zinc Fingers


  • DNA-Binding Proteins
  • EGR2 protein, human
  • Early Growth Response Protein 2
  • Egr2 protein, mouse
  • Transcription Factors
  • Naloxone