Faculty Collaboration Database

Subtype composition and responses of respiratory neurons in the pre-botzinger region to pulmonary afferent inputs in dogs. J Neurophysiol 2005 May;93(5):2674-87

Date

12/17/2004

Pubmed ID

15601729

DOI

10.1152/jn.01206.2003

Scopus ID

2-s2.0-17644375473 (requires institutional sign-in at Scopus site)   27 Citations

Abstract

The brain stem pre-Botzinger complex (pre-BC) plays an important role in respiratory rhythm generation. However, it is not clear what function each subpopulation of neurons in the pre-BC serves. The purpose of the present studies was to identify neuronal subpopulations of the canine pre-BC and to characterize the neuronal responses of subpopulations to experimentally imposed changes in inspiratory (I) and expiratory (E) phase durations. Lung inflations and electrical stimulation of the cervical vagus nerve were used to produce changes in respiratory phase timing via the Hering-Breuer reflex. Multibarrel micropipettes were used to record neuronal activity and for pressure microejection in decerebrate, paralyzed, ventilated dogs. The pre-BC region was functionally identified by eliciting tachypneic phrenic neural responses to localized microejections of DL-homocysteic acid. Antidromic stimulation and spike-triggered averaging techniques were used to identify bulbospinal and cranial motoneurons, respectively. The results indicate that the canine pre-BC region consists of a heterogeneous mixture of propriobulbar I and E neuron subpopulations. The neuronal responses to ipsi-, contra-, and bilateral pulmonary afferent inputs indicated that I and E neurons with decrementing patterns were the only neurons with responses consistently related to phase duration. Late-I neurons were excited, but most other types of I neurons were inhibited or unresponsive. E neurons with augmenting or parabolic discharge patters were inhibited by ipsilateral inputs but excited by contra- and bilateral inputs. Late-E neurons were more frequently encountered and were inhibited by ipsi- and bilateral inputs, but excited by contralateral inputs. The results suggest that only a limited number of neuron subpopulations may be involved in rhythmogenesis, whereas many neuron types may be involved in motor pattern generation.

Author List

Krolo M, Tonkovic-Capin V, Stucke AG, Stuth EA, Hopp FA, Dean C, Zuperku EJ

Authors

Astrid G. Stucke MD Professor in the Anesthesiology department at Medical College of Wisconsin
Eckehard A. Stuth MD Professor in the Anesthesiology department at Medical College of Wisconsin
Edward J. Zuperku PhD Professor in the Anesthesiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Afferent Pathways
Animals
Brain Stem
Cell Count
Chi-Square Distribution
Dogs
Dose-Response Relationship, Radiation
Electric Stimulation
Evoked Potentials, Motor
Female
Functional Laterality
History, Ancient
Homocysteine
Lung
Male
Neural Inhibition
Neurons
Reaction Time
Respiration
Vagus Nerve