Date Thesis Awarded

5-2017

Access Type

Honors Thesis -- Access Restricted On-Campus Only

Degree Name

Bachelors of Science (BS)

Department

Chemistry

Advisor

Christopher Del Negro

Committee Members

Randolph Coleman

Dana Lashley

Douglas Young

Abstract

The preBötzinger complex (preBötC) is the central pattern generator for inspiratory behaviors. Previous studies on perinatal mice and in vitro suggest that Dbx1-derived neurons within the preBötC form the core oscillator. Here, we provide support for the Dbx1 core hypothesis and show that Dbx1-derived neurons are essential for respiratory rhythmogenesis in adult mice. Using optogenetic strategies, we transiently hyperpolarized Dbx1 neurons of the preBötC in vitro and in adult mice. In both cases, the inspiratory rhythm was disrupted. It is possible that axons from Dbx1 neurons projecting into the preBötC were also hyperpolarized, leading to disfacilitation. To determine if this is the case, we conducted a second optogenetic study targeting the preBötC in its entirety. Hyperpolarization of the preBötC in sedated mice resulted in results like those seen from only hyperpolarizing Dbx1 preBötC neurons. Thus, we conclude the disruption of inspiratory rhythm is attributed to the hyperpolarization of Dbx1 preBötC neurons and not disfacilitation.

Recommended Citation

Pham, Francis D., "Optogenetic Investigations of the PreBötzinger Complex: Support for the Dbx1 Core Hypothesis" (2017). Undergraduate Honors Theses. William & Mary. Paper 1034.
https://scholarworks.wm.edu/honorstheses/1034