LOCALIZATION AND FUNCTIONAL ORGANIZATION OF BULBAR AND PONTINE RESPIRATORY NEURONS IN THE RABBIT

Respiration ◽  
1981 ◽  
pp. 579-586
Author(s):  
T. Hukuhara ◽  
K. Goto ◽  
K. Takano ◽  
Y. Hattammaru
Keyword(s):  
Functional Organization ◽  
Respiratory Neurons

Intracellular recordings from different types of medullary respiratory neurons of the cat

1975 ◽  
Vol 38 (5) ◽  
pp. 1162-1171 ◽  
Author(s):  
D. W. Richter ◽  
F. Heyde ◽  
M. Gabriel
Keyword(s):  
Functional Organization ◽  
Silent Period ◽  
Membrane Conductance ◽  
Rhythmic Activity ◽  
Excitatory Input ◽  
Respiratory Neurons ◽  
Inhibitory Input ◽  
Different Types ◽  
Conductance Changes ◽  
Almost All

Respiratory neurons were recorded intracellularly within the lateral region of the lower brain stem of vagotomized and artificially ventilated cats. Bulbospinal, vagal, and antidromically nonresponsive types of neurons were distinguished by means of vagal and intraspinal stimulation. Almost all types of neurons discharged a burst of action potentials during one of the two phases of the central respiratory cycle, as indicated by phrenic nerve activity. The discharge pattern of the different types of neurons were described. The origin of the spntaneous changes of the membrane potential was investigated by measurements of the reversal potentials and membrane conductance changes. The results reveal that both inspiratory and expiratory types of neurons receive an excitatory input during their discharge period, and a reciprocal inhibitory input during their silent period. In addition, one type of neuron was described which receives inhibitory inputs during both inspiration and expiration. Recurrent inhibition, as indicated by hyperpolarizing postsynaptic potentials and membrane conductance changes following the antidromic action potential seems to exist only within the network of the vagal neurons. Suggestions are made about the functional organization of the neuronal network of the medullary respiratory system and the mechanism generating its rhythmic activity.

scholarly journals Characterization of respiratory neurons in the rostral ventrolateral medulla, an area critical for vocal production in songbirds

2013 ◽  
Vol 109 (4) ◽  
pp. 948-957 ◽  
Author(s):  
Judith McLean ◽  
Sarah Bricault ◽  
Marc F. Schmidt
Keyword(s):  
Functional Organization ◽  
Cell Types ◽  
Pattern Generation ◽  
Single Units ◽  
Respiratory Neurons ◽  
Ventrolateral Medulla ◽  
Neural Firing ◽  
Vocal Production ◽  
Ideal System ◽  
Discharge Patterns

Much is known about the neuronal cell types and circuitry of the mammalian respiratory brainstem and its role in normal, quiet breathing. Our understanding of the role of respiration in the context of vocal production, however, is very limited. Songbirds contain a well-defined neural circuit, known as the song system, which is necessary for song production and is strongly coupled to the respiratory system. A major target of this system is nucleus parambigualis (PAm) in the ventrolateral medulla, a structure that controls inspiration by way of its bulbospinal projections but is also an integral part of the song-pattern generation circuit by way of its “thalamocortical” projections to song-control nuclei in the telencephalon. We have mapped out PAm to characterize the cell types and its functional organization. Extracellular single units were obtained in anesthetized adult male zebra finches while measuring air sac pressure to monitor respiration. Single units were characterized by their discharge patterns and the phase of the activity in the respiratory cycle. Several classes of neurons were identified and were analogous to those reported for mammalian medullary respiratory neurons. The majority of the neurons in PAm was classified as inspiratory augmenting or preinspiratory, although other basic discharge patterns were observed as well. The well-characterized connectivity of PAm within the vocal motor circuit and the similarity of its neural firing patterns to the rostral ventral respiratory group and pre-Bötzinger complex of mammals make it an ideal system for investigating the integration of breathing and vocalization.

scholarly journals Some effects of pentobarbital on the functional organization of respiratory neurons in the central respiratory mechanisms in the brain stem of the rabbit

1978 ◽  
Vol 28 ◽  
pp. 41
Author(s):  
Takehiko Hukuhara ◽  
Shigeru Kageyama ◽  
Yuriko Kiguchi ◽  
Kazutoshi Goto ◽  
Yoshinobu Nishikawa ◽  
...  
Keyword(s):  
Brain Stem ◽  
Functional Organization ◽  
Respiratory Neurons ◽  
The Brain

Organization of transcription and pre-mRNA splicing within the mammalian cell nucleus

1995 ◽  
Vol 53 ◽  
pp. 768-769
Author(s):  
D.L. Spector ◽  
S. Huang ◽  
S. Kaurin
Keyword(s):  
Rna Polymerase Ii ◽  
Cell Nucleus ◽  
Functional Organization ◽  
Mrna Splicing ◽  
Splicing Factors ◽  
Interchromatin Granule Clusters ◽  
Interchromatin Granule ◽  
Nuclear Regions ◽  
Relationship Of ◽  
Perichromatin Fibrils

We have been interested in the organization of RNA polymerase II transcription and pre-mRNA splicing within the cell nucleus. Several models have been proposed for the functional organization of RNA within the eukaryotic nucleus and for the relationship of this organization to the distribution of pre-mRNA splicing factors. One model suggests that RNAs which must be spliced are capable of recruiting splicing factors to the sites of transcription from storage and/or reassembly sites. When one examines the organization of splicing factors in the nucleus in comparison to the sites of chromatin it is clear that splicing factors are not localized in coincidence with heterochromatin (Fig. 1). Instead, they are distributed in a speckled pattern which is composed of both perichromatin fibrils and interchromatin granule clusters. The perichromatin fibrils are distributed on the periphery of heterochromatin and on the periphery of interchromatin granule clusters as well as being diffusely distributed throughout the nucleoplasm. These nuclear regions have been previously shown to represent initial sites of incorporation of 3H-uridine.

Immunolocalization of nuclear antigens in cryofixed cells which have been prepared by molecular distillation drying or freeze-substitution

1990 ◽  
Vol 48 (3) ◽  
pp. 898-899
Author(s):  
David L. Spector ◽  
Robert J. Derby
Keyword(s):  
Cell Nucleus ◽  
Molecular Distillation ◽  
Functional Organization ◽  
Freeze Substitution ◽  
3 Dimensional ◽  
Small Nuclear Ribonucleoprotein ◽  
Nuclear Antigens ◽  
Dimensional Reconstruction ◽  
Nuclear Regions ◽  
Immunoperoxidase Labeling

Studies in our laboratory are involved in evaluating the structural and functional organization of the mammalian cell nucleus. Since several major classes (U1, U2, U4/U6, U5) of small nuclear ribonucleoprotein particles (snRNPs) play a crucial role in the processing of pre-mRNA molecules, we have been interested in the localization of these particles within the cell nucleus. Using pre-embedding immunoperoxidase labeling combined with 3-dimensional reconstruction, we have recently shown that nuclear regions enriched in snRNPs form a reticular network within the nucleoplasm which extends between the nucleolar surface and the nuclear envelope. In the present study we were inte rested in extending these nuclear localizations using cell preparation techniques which avoid slow penetration of fixatives, chemical crosslinking of potential antigens and solvent extraction. CHOC 400 cells were cryofixed using a CF 100 ultra rapid cooling device (LifeCell Corp.). After cryofixation cells were molecular distillation dried, vapor osmicated, in filtra ted in 100% Spurr resin in vacuo and polymerized in molds a t 60°C. Using this procedure we were able to evaluate the distribution of snRNPs in resin embedded cells which had not been chemically fixed, incubated in cryoprotectants or extracted with solvents.

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