Abrupt changes in pentobarbital sensitivity in preBötzinger complex region, hypoglossal motor nucleus, nucleus tractus solitarius, and cortex during rat transitional period (P10-P15)

Respir Physiol Neurobiol. 2015 Feb 1:207:61-71. doi: 10.1016/j.resp.2014.12.016. Epub 2014 Dec 27.

Abstract

On postnatal days P10-P15 in rat medulla, neurotransmitter receptor subunit composition shifts toward a more mature phenotype. Since medullary GABAARs regulate cardiorespiratory function, abrupt alterations in GABAergic synaptic inhibition could disrupt homeostasis. We hypothesized that GABAARs on medullary neurons become more resistant to positive allosteric modulation during P10-P15. Medullary and cortical slices from P10 to P20 rats were used to record spontaneous action potentials in pre-Botzinger Complex (preBötC-region), hypoglossal (XII) motor nucleus, nucleus tractus solitarius (NTS), and cortex during exposure to pentobarbital (positive allosteric modulator of GABAARs). On P14, pentobarbital resistance abruptly increased in preBötC-region and decreased in NTS, but these changes in pentobarbital resistance were not present on P15. Pentobarbital resistance decreased in XII motor nucleus during P11-P15 with a nadir at P14. Abrupt changes in pentobarbital resistance indicate changes in GABAergic receptor composition and function that may compensate for potential increased GABAergic inhibition and respiratory depression that occurs during this key developmental transitional period.

Keywords: Development; Hypoglossal; Nucleus tractus solitaries; Pentobarbital; preBotzinger complex.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects
  • Age Factors
  • Animals
  • Animals, Newborn
  • Cerebral Cortex* / cytology
  • Cerebral Cortex* / drug effects
  • Cerebral Cortex* / growth & development
  • Hypnotics and Sedatives / pharmacology*
  • In Vitro Techniques
  • Neural Pathways / drug effects
  • Neural Pathways / physiology
  • Neurons / drug effects*
  • Neurons / physiology
  • Pentobarbital / pharmacology*
  • Rats
  • Rats, Wistar
  • Respiratory Center* / cytology
  • Respiratory Center* / drug effects
  • Respiratory Center* / growth & development
  • Solitary Nucleus* / cytology
  • Solitary Nucleus* / drug effects
  • Solitary Nucleus* / growth & development
  • Time Factors

Substances

  • Hypnotics and Sedatives
  • Pentobarbital