Cerebellar, medullary and spinal afferent connections of the paramedian reticular nucleus in the cat

1985 ◽  
Vol 332 (2) ◽  
pp. 267-282 ◽  
Author(s):  
K.V. Elisevich ◽  
A.W. Hrycyshyn ◽  
B.A. Flumerfelt
1975 ◽  
Vol 228 (4) ◽  
pp. 1002-1003 ◽  
Author(s):  
DG Taylor ◽  
tgl Gebber

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.


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

1958 ◽  
Vol 192 (2) ◽  
pp. 305-310 ◽  
Author(s):  
Clark T. Randt ◽  
William F. Collins ◽  
Hamilton S. Davis ◽  
William H. Dillon

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.


2021 ◽  
Author(s):  
Atsushi Yoshida ◽  
Misaki Inoue ◽  
Fumihiko Sato ◽  
Yayoi Morita ◽  
Yumi Tsutsumi ◽  
...  

Abstract The supratrigeminal nucleus (Su5) is a key structure for controlling jaw-movements since it receives proprioceptive sensation from jaw-closing muscle spindles (JCMSs) and sends projection to the trigeminal motor nucleus (Mo5). However, the central projection and regulation of JCMS proprioceptive sensation have not been fully understood. Therefore, we aimed to reveal the efferents and afferents of the Su5 by means of neuronal tract tracings. Anterograde tracer injections into the Su5 revealed that the Su5 sent contralateral projections (or bilateral projections with a contralateral predominance) to the Su5, basilar pontine nuclei, pontine reticular nucleus, deep mesencephalic nucleus, superior colliculus, caudo-ventromedial edge of ventral posteromedial thalamic nucleus, parafascicular thalamic nucleus, zona incerta, and lateral hypothalamus, and ipsilateral projections (or bilateral projections with an ipsilateral predominance) to the intertrigeminal region, trigeminal oral subnucleus, dorsal medullary reticular formation, and hypoglossal nucleus as well as the Mo5. Retrograde tracer injections into the Su5 demonstrated that the Su5 received bilateral projections with a contralateral predominance (or contralateral projections) from the primary and secondary somatosensory cortices, granular insular cortex and Su5, and ipsilateral projections (or bilateral projections with an ipsilateral predominance) from the dorsal peduncular cortex, bed nuclei of stria terminalis, central amygdaloid nucleus, lateral hypothalamus, parasubthalamic nucleus, trigeminal mesencephalic nucleus, parabrachial nucleus, juxtatrigeminal region, trigeminal oral and caudal subnuclei, and dorsal medullary reticular formation. These findings suggest that the Su5 receiving JCMS proprioceptive sensation has efferent and afferent connections with multiple brain regions, which are involved in emotional and autonomic functions as well as orofacial motor functions.


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