Developmental nicotine exposure disrupts dendritic arborization patterns of hypoglossal motoneurons in the neonatal rat

Dev Neurobiol. 2016 Oct;76(10):1125-37. doi: 10.1002/dneu.22379. Epub 2016 Feb 8.

Abstract

Maternal smoking or use of other products containing nicotine during pregnancy can have significant adverse consequences for respiratory function in neonates. We have shown, in previous studies, that developmental nicotine exposure (DNE) in a model system compromises the normal function of respiratory circuits within the brainstem. The effects of DNE include alterations in the excitability and synaptic interactions of the hypoglossal motoneurons, which innervate muscles of the tongue. This study was undertaken to test the hypothesis that these functional consequences of DNE are accompanied by changes in the dendritic morphology of hypoglossal motoneurons. Hypoglossal motoneurons in brain stem slices were filled with neurobiotin during whole-cell patch clamp recordings and subjected to histological processing to reveal dendrites. Morphometric analysis, including the Sholl method, revealed significant effects of DNE on dendritic branching patterns. In particular, whereas within the first five postnatal days there was significant growth of the higher-order dendritic branches of motoneurons from control animals, the growth was compromised in motoneurons from neonates that were subjected to DNE. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 76: 1125-1137, 2016.

Keywords: dendrite; gestational; motor neuron; nicotine; tobacco.

Publication types

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

MeSH terms

  • Animals
  • Animals, Newborn
  • Brain Stem / drug effects
  • Brain Stem / growth & development*
  • Brain Stem / pathology
  • Brain Stem / physiopathology
  • Dendrites / drug effects
  • Dendrites / pathology
  • Dendrites / physiology
  • Disease Models, Animal
  • Female
  • Hypoglossal Nerve / drug effects
  • Hypoglossal Nerve / growth & development*
  • Hypoglossal Nerve / pathology
  • Hypoglossal Nerve / physiopathology
  • Motor Neurons / drug effects
  • Motor Neurons / pathology*
  • Motor Neurons / physiology
  • Neuroanatomical Tract-Tracing Techniques
  • Nicotine / toxicity*
  • Nicotinic Agonists / toxicity*
  • Patch-Clamp Techniques
  • Pregnancy
  • Prenatal Exposure Delayed Effects*
  • Rats, Sprague-Dawley
  • Synaptic Transmission
  • Tissue Culture Techniques

Substances

  • Nicotinic Agonists
  • Nicotine