Effects of prenatal nicotine exposure on the age-related ventilatory response to hypercapnia in neonatal mice

Brzoza, Natalie

Effects of prenatal nicotine exposure on the age-related ventilatory response to hypercapnia in neonatal mice

Persistent URL

http://hdl.handle.net/10456/26349

Author(s)

Brzoza, Natalie

Date Issued

April 2, 2012

Abstract

Sudden Infant Death Syndrome (SIDS) is thought to result from an abnormality in ventilatory control that prevents an infant from regulating ventilation in the presence of an exogenous stressor during a critical period in development. Prenatal exposure to cigarette smoke, and particularly nicotine, is thought to impair development of peripheral and central chemoreceptors in the brainstem, resulting in the inability to properly regulate breathing. This study sought to determine the effects of prenatal nicotine exposure on the ventilatory response to prolonged, sustained increases in hypercapnia in neonatal mice. Ten mice pups served as controls and seven mice pups were prenatally exposed to 3 mg/kg of nicotine, which was administered to maternal mice through a drinking solution throughout gestation and the testing period. Pressure plethysmography was used to measure the ventilatory responses of the control and nicotine litters in response to 3 min exposures to 2 % step-wise increases in hypercapnia from 0 to 6 % CO2 on postnatal days 1, 2, 3, 5, 8, and 11. Ventilatory parameters of frequency, tidal volume, and minute ventilation were analyzed and represented as functions of % CO2 to determine the sensitivity of the mice to CO2. The results of this study found that mice prenatally exposed to nicotine exhibited apneas and a blunted ventilatory response to hypercapnia; however, they were found to demonstrate both lower or higher sensitivities to CO2 than controls. These results suggest that even a low dose of nicotine can elicit impairments in ventilation.

Honors

Neuroscience, 2012

First Reader(s)

Coates, E. Lee