Comparative Anatomical Aspects of the Mammalian Brain Stem and the Cord: Volumes I and II

Neurology ◽  
1971 ◽  
Vol 21 (12) ◽  
pp. 1262-1262
Author(s):  
M. B. CARPENTER
Keyword(s):  
Brain Stem ◽  
Mammalian Brain

Role of gap junctions in CO2 chemoreception and respiratory control

2002 ◽  
Vol 283 (4) ◽  
pp. L665-L670 ◽  
Author(s):  
Jay B. Dean ◽  
David Ballantyne ◽  
Daniel L. Cardone ◽  
Joseph S. Erlichman ◽  
Irene C. Solomon
Keyword(s):  
Gap Junctions ◽  
Brain Stem ◽  
Ionic Current ◽  
Respiratory Control ◽  
Mammalian Brain ◽  
Future Research ◽  
Cell Coupling ◽  
Respiratory Rhythmogenesis ◽  
Cell Cell

Gap junctions are composed of connexins, which are organized into intercellular channels that form transmembrane pathways between neurons (cell-cell coupling), and in some cases, neurons and glia, for exchange of ions and small molecules (metabolic coupling) and ionic current (electrical coupling). Cell-cell coupling via gap junctions has been identified in brain stem neurons that function in CO2/H+ chemoreception and respiratory rhythmogenesis; however, the exact roles of gap junctions in respiratory control are undetermined. Here we review the methods commonly used to study gap junctions in the mammalian brain stem under in vitro and in vivo conditions and briefly summarize the anatomical, pharmacological, and electrophysiological evidence to date supporting roles for cell-cell coupling in respiratory rhythmogenesis and central chemoreception. Specific research questions related to the role of gap junctions in respiratory control are suggested for future research.

scholarly journals Spatial and Functional Architecture of the Mammalian Brain Stem Respiratory Network: A Hierarchy of Three Oscillatory Mechanisms

2007 ◽  
Vol 98 (6) ◽  
pp. 3370-3387 ◽  
Author(s):  
J. C. Smith ◽  
A. P. L. Abdala ◽  
H. Koizumi ◽  
I. A. Rybak ◽  
J. F. R. Paton
Keyword(s):  
Brain Stem ◽  
Sodium Current ◽  
Respiratory Rhythm ◽  
Central Pattern Generators ◽  
Respiratory Neurons ◽  
Mammalian Brain ◽  
Two Phase ◽  
Respiratory Network ◽  
Three Phase ◽  
The One

Mammalian central pattern generators (CPGs) producing rhythmic movements exhibit extremely robust and flexible behavior. Network architectures that enable these features are not well understood. Here we studied organization of the brain stem respiratory CPG. By sequential rostral to caudal transections through the pontine-medullary respiratory network within an in situ perfused rat brain stem–spinal cord preparation, we showed that network dynamics reorganized and new rhythmogenic mechanisms emerged. The normal three-phase respiratory rhythm transformed to a two-phase and then to a one-phase rhythm as the network was reduced. Expression of the three-phase rhythm required the presence of the pons, generation of the two-phase rhythm depended on the integrity of Bötzinger and pre-Bötzinger complexes and interactions between them, and the one-phase rhythm was generated within the pre-Bötzinger complex. Transformation from the three-phase to a two-phase pattern also occurred in intact preparations when chloride-mediated synaptic inhibition was reduced. In contrast to the three-phase and two-phase rhythms, the one-phase rhythm was abolished by blockade of persistent sodium current ( INaP). A model of the respiratory network was developed to reproduce and explain these observations. The model incorporated interacting populations of respiratory neurons within spatially organized brain stem compartments. Our simulations reproduced the respiratory patterns recorded from intact and sequentially reduced preparations. Our results suggest that the three-phase and two-phase rhythms involve inhibitory network interactions, whereas the one-phase rhythm depends on INaP. We conclude that the respiratory network has rhythmogenic capabilities at multiple levels of network organization, allowing expression of motor patterns specific for various physiological and pathophysiological respiratory behaviors.

BURSTING INDUCED BY EXCITATORY SYNAPTIC COUPLING IN THE PRE-BÖTZINGER COMPLEX

2012 ◽  
Vol 22 (05) ◽  
pp. 1250114 ◽  
Author(s):  
LIXIA DUAN ◽  
DEHONG ZHAI ◽  
XUHUI TANG
Keyword(s):  
Brain Stem ◽  
Bifurcation Analysis ◽  
Cell Model ◽  
Mammalian Brain ◽  
Synaptic Coupling ◽  
Model Network ◽  
Cell Network ◽  
Bötzinger Complex ◽  
Coupled Cells ◽  
Slow Decomposition

In this paper, we study and classify the bursting in a two-cell network of excitatory neuron within the pre-Bötzinger complex of the mammalian brain stem. We investigate the effects of parameters g Na and g K on the bursting generation and pattern transitions in the two-cell model network with synaptic coupling by the fast–slow decomposition and bifurcation analysis approach. Comparing the firing patterns of the uncoupled and coupled cells, we found that the bursting patterns are the same both for a single and two-cell model network with the parameter g Na changed, while they are different with the parameter g K changed. Our results are instructive for further understanding the dependence of the complex firing activities of the network on the firing activities of the single cell in the network.

Neural mechanisms generating locomotion studied in mammalian brain stem‐spinal cord in vitro

1988 ◽  
Vol 2 (7) ◽  
pp. 2283-2288 ◽  
Author(s):  
Jeffrey C. Smith ◽  
Jack L. Feldman ◽  
Brian J. Schmidt
Keyword(s):  
Spinal Cord ◽  
Brain Stem ◽  
Neural Mechanisms ◽  
Mammalian Brain

Development of Sound Localization Mechanisms in the Mongolian Gerbil Is Shaped by Early Acoustic Experience

2005 ◽  
Vol 94 (2) ◽  
pp. 1028-1036 ◽  
Author(s):  
Armin H. Seidl ◽  
Benedikt Grothe
Keyword(s):  
Brain Stem ◽  
Sound Localization ◽  
Low Frequency ◽  
Mammalian Brain ◽  
Medial Superior Olive ◽  
Visual Inputs ◽  
Auditory Brain Stem ◽  
Barn Owls ◽  
Neuronal Representation ◽  
Acoustic Experience

Sound localization is one of the most important tasks performed by the auditory system. Differences in the arrival time of sound at the two ears are the main cue to localize low-frequency sound in the azimuth. In the mammalian brain, such interaural time differences (ITDs) are encoded in the auditory brain stem; first by the medial superior olive (MSO) and then transferred to higher centers, such as the dorsal nucleus of the lateral lemniscus (DNLL), a brain stem nucleus that gets a direct input from the MSO. Here we demonstrate for the first time that ITD sensitivity in gerbils undergoes a developmental maturation after hearing onset. We further show that this development can be disrupted by altering the animal's acoustic experience during a critical period. In animals that had been exposed to omnidirectional white noise during a restricted time period right after hearing onset, ITD tuning did not develop normally. Instead, it was similar to that of juvenile animals 3 days after hearing onset, with the ITD functions not adjusted to the physiological range. Animals that had been exposed to omnidirectional noise as adults did not show equivalent abnormal ITD tuning. The development presented here is in contrast to that of the development of neuronal representation of ITDs in the midbrain of barn owls and interaural intensity differences in ferrets, where the representations are adjusted by an interaction of auditory and visual inputs. The development of ITD tuning presented here most likely depends on normal acoustic experience and may be related to the maturation of inhibitory inputs to the ITD detector itself.

Permeability of the microcirculation in area postrema of rat

1988 ◽  
Vol 46 ◽  
pp. 348-349
Author(s):  
Shams M. Ghoneim ◽  
Frank M. Faraci ◽  
Gary L. Baumbach
Keyword(s):  
Brain Stem ◽  
Area Postrema ◽  
Upper Body ◽  
Sprague Dawley ◽  
Sodium Cacodylate ◽  
Acute Hypertension ◽  
Sprague Dawley Rats ◽  
Ultrastructural Characteristics ◽  
The Brain ◽  
Adjacent Brain

The area postrema is a circumventricular organ in the brain stem and is one of the regions in the brain that lacks a fully functional blood-brain barrier. Recently, we found that disruption of the microcirculation during acute hypertension is greater in area postrema than in the adjacent brain stem. In contrast, hyperosmolar disruption of the microcirculation is greater in brain stem. The objective of this study was to compare ultrastructural characteristics of the microcirculation in area postrema and adjacent brain stem.We studied 5 Sprague-Dawley rats. Horseradish peroxidase was injected intravenously and allowed to circulate for 1, 5 or 15 minutes. Following perfusion of the upper body with 2.25% glutaraldehyde in 0.1 M sodium cacodylate, the brain stem was removed, embedded in agar, and chopped into 50-70 μm sections with a TC-Sorvall tissue chopper. Sections of brain stem were incubated for 1 hour in a solution of 3,3' diaminobenzidine tetrahydrochloride (0.05%) in 0.05M Tris buffer with 1% H2O2.

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