Neurophysiological Studies of Harmaline-Induced Tremor in the Cat

Harmaline induces in the cat a generalized tremor, synchronous in all muscles, at a frequency of 8–12/s. This tremor has a central origin since motoneuronal rhythmic firing persists after paralysis or deafferentation. Intracellular recordings of lumbar motoneurons reveal spontaneous rhythmic EPSPs under harmaline; this rhythmic activity is not reset by antidromic stimulation. The cerebellum and the lower brain stem reticular formation appear to be primarily involved in the elaboration of supraspinal tremorogenic impulses, which are transmitted to segmental level by crossed and uncrossed reticulospinal fibers coursing on either side in the ventral half of the spinal cord.

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Integrative Control Mechanisms for Cardiorespiratory and Somatomotor Functions in the Reticular Formation of the Lower Brain Stem

Cardiorespiratory and Cardiosomatic Psychophysiology ◽

10.1007/978-1-4757-0360-3_2 ◽

1986 ◽

pp. 9-39 ◽

Cited By ~ 5

Author(s):

P. Langhorst ◽

G. Schulz ◽

M. Lambertz

Keyword(s):

Brain Stem ◽

Reticular Formation ◽

Control Mechanisms ◽

Lower Brain Stem

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Parabrachial nucleus neurons projecting to the lower brain stem and the spinal cord. A study in the cat by the Fink-Heimer and the horseradish peroxidase methods

Experimental Neurology ◽

10.1016/0014-4886(80)90037-0 ◽

1980 ◽

Vol 70 (2) ◽

pp. 403-413 ◽

Cited By ~ 46

Author(s):

Yoshiki Takeuchi ◽

Masanori Uemura ◽

Kojyuro Matsuda ◽

Ryotaro Matsushima ◽

Noboru Mizuno

Keyword(s):

Spinal Cord ◽

Horseradish Peroxidase ◽

Brain Stem ◽

Parabrachial Nucleus ◽

Lower Brain Stem

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Dextromethorphan blocks glycine-induced single currents in cultured neurons of the spinal cord and lower brain stem of rats.

The Japanese Journal of Pharmacology ◽

10.1016/s0021-5198(19)37295-6 ◽

1996 ◽

Vol 71 ◽

pp. 264

Author(s):

Hidenao Fukushima ◽

Kazuo Takahama ◽

Yoichiro Isohama ◽

Hirofumi Kai ◽

Takeshi Miyata

Keyword(s):

Spinal Cord ◽

Brain Stem ◽

Cultured Neurons ◽

Lower Brain Stem

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Distribution of corticospinal neurons with collaterals to the lower brain stem reticular formation in monkey (Macaca fascicularis)

Experimental Brain Research ◽

10.1007/bf00248864 ◽

1989 ◽

Vol 74 (2) ◽

Cited By ~ 126

Author(s):

K. Keizer ◽

H.G.J.M. Kuypers

Keyword(s):

Brain Stem ◽

Reticular Formation ◽

Macaca Fascicularis ◽

Lower Brain Stem

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Harmaline-induced rhythmic activity of cerebellar and lower brain stem neurons

Brain Research ◽

10.1016/0006-8993(71)90174-0 ◽

1971 ◽

Vol 32 (1) ◽

pp. 246-250 ◽

Cited By ~ 142

Author(s):

Y. Lamarre ◽

C. de Montigny ◽

M. Dumont ◽

M. Weiss

Keyword(s):

Brain Stem ◽

Rhythmic Activity ◽

Lower Brain Stem

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Rhythmic activity of neurons in the rostral ventrolateral medulla of conscious cats: effect of removal of vestibular inputs

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00265.2011 ◽

2011 ◽

Vol 301 (4) ◽

pp. R937-R946 ◽

Cited By ~ 15

Author(s):

Susan M. Barman ◽

Yoichiro Sugiyama ◽

Takeshi Suzuki ◽

Lucy A. Cotter ◽

Vincent J. DeStefino ◽

...

Keyword(s):

Rhythmic Activity ◽

Rostral Ventrolateral Medulla ◽

Ventrolateral Medulla ◽

Limited Area ◽

Surgical Removal ◽

Naturally Occurring ◽

Neurophysiological Studies ◽

Rhythmic Discharge ◽

Rhythmic Firing ◽

Descending Projections

Although it is well established that bulbospinal neurons located in the rostral ventrolateral medulla (RVLM) play a pivotal role in regulating sympathetic nerve activity and blood pressure, virtually all neurophysiological studies of this region have been conducted in anesthetized or decerebrate animals. In the present study, we used time- and frequency-domain analyses to characterize the naturally occurring discharges of RVLM neurons in conscious cats. Specifically, we compared their activity to fluctuations in carotid artery blood flow to identify neurons with cardiac-related (CR) activity; we then considered whether neurons with CR activity also had a higher-frequency rhythmic firing pattern. In addition, we ascertained whether the surgical removal of vestibular inputs altered the rhythmic discharge properties of RVLM neurons. Less than 10% of RVLM neurons expressed CR activity, although the likelihood of observing a neuron with CR activity in the RVLM varied between recording sessions, even when tracking occurred in a very limited area and was higher after vestibular inputs were surgically removed. Either a 10-Hz or a 20- to 30-Hz rhythmic discharge pattern coexisted with the CR discharges in some of the RVLM neurons. Additionally, the firing rate of RVLM neurons, including those with CR activity, decreased after vestibular lesions. These findings raise the prospect that RVLM neurons may or may not express rhythmic firing patterns at a particular time due to a variety of influences, including descending projections from higher brain centers and sensory inputs, such as those from the vestibular system.

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Immunocytochemical studies on the localization of glucocorticoid receptor immunoreactive nerve cells in the lower brain stem and spinal cord of the male rat using a monoclonal antibody against rat liver glucocorticoid receptor

Neuroscience Letters ◽

10.1016/0304-3940(85)90372-6 ◽

1985 ◽

Vol 60 (1) ◽

pp. 1-6 ◽

Cited By ~ 91

Author(s):

K. Fuxe ◽

A. Härfstrand ◽

L.F. Agnati ◽

Z.-Y. Yu ◽

A. Cintra ◽

...

Keyword(s):

Spinal Cord ◽

Monoclonal Antibody ◽

Glucocorticoid Receptor ◽

Brain Stem ◽

Rat Liver ◽

Nerve Cells ◽

Male Rat ◽

Immunocytochemical Studies ◽

Lower Brain Stem

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High pressure modifies respiratory activity in isolated rat brain stem-spinal cord

Journal of Applied Physiology ◽

10.1152/jappl.1991.71.2.537 ◽

1991 ◽

Vol 71 (2) ◽

pp. 537-545 ◽

Cited By ~ 13

Author(s):

A. Tarasiuk ◽

Y. Grossman

Keyword(s):

Spinal Cord ◽

Brain Stem ◽

Sensory Input ◽

Respiratory Activity ◽

Cranial Nerves ◽

Rhythmic Activity ◽

Respiratory Center ◽

Sensory Afferents ◽

Hyperbaric Pressure ◽

Central Respiratory Activity

Exposure to hyperbaric pressure causes a constellation of motor disturbances and ventilatory difficulties in animals and humans. The present experiments were designed to examine the effects of hyperbaric pressure on the rhythmic activity of the respiratory center in the absence of peripheral sensory afferents by using the isolated brain stem-spinal cord preparation from newborn rats. In addition, we examined the effect of pressure on the response of the respiratory center to sensory input from the trigeminal and vagus cranial nerves. Hyperbaric pressure significantly depressed the mean inspiratory drive (frequency X time integral of single electrical bursts) in C5 but not in C1 ventral roots. Pressure also reduced the amount of inhibition on the respiratory activity normally exerted by trigeminal and vagal nerve stimulation and in some cases reversed it to excitation. It is concluded that in the absence of sensory input, exposure to hyperbaric pressure depresses central respiratory activity. However, in an intact system, it may alter the balance between excitation and inhibition and render the system hyperexcitable to the same sensory input.

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