Descending projections from the dorsolateral pontine tegmentum to the paramedian reticular nucleus of the caudal medulla in the cat

1990 ◽  
Vol 517 (1-2) ◽  
pp. 224-228 ◽  
Author(s):  
Priyattam J. Shiromani ◽  
Y.Y. Lai ◽  
Jerome M. Siegel
Keyword(s):  
Reticular Nucleus ◽  
Pontine Tegmentum ◽  
Paramedian Reticular Nucleus ◽  
Caudal Medulla ◽  
Descending Projections

Baroreceptor mechanisms controlling sympathetic nervous rhythms of central origin

1975 ◽  
Vol 228 (4) ◽  
pp. 1002-1003 ◽  
Author(s):  
DG Taylor ◽  
tgl Gebber
Keyword(s):  
Slow Wave ◽  
Cardiac Cycle ◽  
Reticular Nucleus ◽  
Direct Result ◽  
Renal Nerves ◽  
Central Origin ◽  
Baroreceptor Reflexes ◽  
Paramedian Reticular Nucleus ◽  
Sympathetic Nervous ◽  
Made In

A study was made in the anesthetized cat of the slow wave of sympathetic nervous discharge (SND) locked in a 1:1 relation to the cardiac cycle (3 cycle/s periodicity). SND was recorded from the preganglionic splanchnic and postganglionic renal nerves. The data contradict the generally accepted view that the slow wave occurs as the direct result of a waxing and waning of baroreceptor nervous discharge. Although baroreceptor denervation unlocked the phase relations between SND and the cardiac cycle, the slow wave persisted and its duration was not changed. Furthermore, the slow wave was aborted by stimuli delivered to the baroreceptor nerves or paramedian reticular nucleus during a time span which accounted for less than 1 percent of the cardiac cycle. It is concluded that the 3 cycle/s periodicity of SND is representative of a vasomotor rhythm of central origin which is entrained to the cardiac cycle by the baroreceptor reflexes. The sympathoinhibitory effect leading to the entrainment of the slow wave is mediated in the brainstem. ta spinal component of baroreceptor-induced sympathoinhibition also was demonstrated.

Reduction of blood PO2 decrease and PCO2 increase during asphyxia by paramedian reticular nucleus in cats

1992 ◽  
Vol 29 (5) ◽  
pp. 573-579 ◽  
Author(s):  
J.M. Yang ◽  
C.W. Ho ◽  
R.H. Lin ◽  
R.T. Lin ◽  
M.T. Lin ◽  
...  
Keyword(s):  
Reticular Nucleus ◽  
Paramedian Reticular Nucleus

Differential Susceptibility of Afferent Pathways to Anesthetic Agents in the Cat

1958 ◽  
Vol 192 (2) ◽  
pp. 305-310 ◽  
Author(s):  
Clark T. Randt ◽  
William F. Collins ◽  
Hamilton S. Davis ◽  
William H. Dillon
Keyword(s):  
Nitrous Oxide ◽  
Differential Susceptibility ◽  
Reticular Nucleus ◽  
Maximal Effect ◽  
Afferent Pathways ◽  
Percentage Decrease ◽  
Quantitative Correlation ◽  
Anesthetic Agents ◽  
Paramedian Reticular Nucleus ◽  
Anesthetic Gases

The effects of nitrous oxide, ethylene and cyclopropane on somatic afferent evoked potentials in the posteroventral lateral nucleus of the thalamus, the peri-aqueductal reticular formation of the midbrain, the deep pretectal region of the midbrain, and the caudal paramedian reticular nucleus of the medulla oblongata were studied in 46 cats immobilized with muscle relaxants. The time of onset to maximal effect, percentage decrease in amplitude of the evoked subcortical potentials and the duration of depression incident to the administration of these anesthetic gases in doses approximating those in clinical use, showed quantitative correlation with the clinically observed potency of nitrous oxide, ethylene and cyclopropane in that order. The anesthetic agents were shown to act differentially on four somatic afferent systems of diverse fiber size and characteristics of transmission suggesting that the anesthetic effect may be determined by factors in addition to the numerical preponderance of synapses in multineuronal systems. The evidence presented suggests more specific susceptibility of small fiber systems to the action of anesthetic agents.

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