Effects of bulbar stimulation and decerebration on visceral afferent responses in the spinal cord

1959 ◽  
Vol 196 (3) ◽  
pp. 674-680 ◽  
Author(s):  
Alan Tolle ◽  
Shaul Feldman ◽  
Carmine D. Clemente
Keyword(s):  
Spinal Cord ◽  
Brain Stem ◽  
Cervical Spinal Cord ◽  
Splanchnic Nerve ◽  
Evoked Responses ◽  
Relay Station ◽  
Sensory Pathways ◽  
Bulbar Stimulation ◽  
Adult Cats ◽  
Stimulation Of

In a series of adult cats immobilized with Flaxedil, the splanchnic nerve was stimulated and visceral afferent responses were recorded in the cervical spinal cord. Simultaneous stimulation of the ventromedial reticular formation (2 volts, 100/sec., 1 msec.) caused an inhibition of the visceral afferent evoked responses central to the first relay station in the cord. Following decerebration, an extinction of evoked visceral afferent responses recorded in the spinal cord was constantly observed upon successive, single-shock, splanchnic nerve stimuli. This latter phenomenon is probably due to a removal of suprabulbar influences on brain stem reticular systems modulating sensory pathways.

Effect of Various Sensory Stimuli on Reflex Laryngeal Adduction

1977 ◽  
Vol 86 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Masafumi Suzuki ◽  
Clarence T. Sasaki
Keyword(s):  
Splanchnic Nerve ◽  
Laryngeal Nerve ◽  
Organ System ◽  
Sensory Nerves ◽  
The Other ◽  
Evoked Responses ◽  
Sensory Stimuli ◽  
Adult Cats ◽  
Repetitive Electrical Stimulation ◽  
Stimulation Of

Various types of sensory stimuli may influence reflex laryngeal adduction. The recurrent laryngeal nerve responses evoked by single shock and repetitive electrical stimulation of a number of sensory nerves have been neurophysiologically observed in twenty-five adult cats. Stimulation of major cranial afferents produces strong adductor responses. The magnitude of these evoked responses is approached only by stimulation of the splanchnic nerve in the abdomen. On the other hand, comparable stimulation of special sensory and spinal somatic sensory nerves produces rapidly attenuated evoked adductor responses. We postulate that while these latter adductor responses may be insufficient to produce strong glottic closure, they may effectively modify phonatory function of the larynx. We have, therefore, attempted to demonstrate the effects of various sensory elicitations upon reflex laryngeal adduction as they may compositely influence both protective and phonatory control of this organ system.

Cervical spinal cord in experimental hydrocephalus

1972 ◽  
Vol 37 (5) ◽  
pp. 538-542 ◽  
Author(s):  
George J. Dohrmann
Keyword(s):  
Spinal Cord ◽  
Brain Stem ◽  
Cervical Spinal Cord ◽  
Central Canal ◽  
Content Type ◽  
Experimental Hydrocephalus ◽  
Physiological Pressure ◽  
The Brain ◽  
Shunting Procedure ◽  
Fine Print

✓ Adult dogs were rendered hydrocephalic by the injection of kaolin into the cisterna magna. One group of dogs was sacrificed 1 month after kaolin administration, and ventriculojugular shunts were performed on the other group. Hydrocephalic dogs with shunts were sacrificed 1 day or 1 week after the shunting procedure. All dogs were perfused with formalin at physiological pressure, and the brain stem and cervical spinal cord were examined by light microscopy. Subarachnoid granulomata encompassed the superior cervical spinal cord and dependent surface of the brain stem. Rarefaction of the posterior white columns and clefts or cavities involving the gray matter posterior to the central canal and/or posterior white columns were present in the spinal cords of both hydrocephalic and shunted hydrocephalic dogs. Predominantly in the dogs with shunts, hemorrhages were noted in the spinal cord in association with the clefts or cavities. A mechanism of ischemia followed by reflow of blood is postulated to explain the hemorrhages in the spinal cords of hydrocephalic dogs with shunts.

Micturition reflexes in the in vitro neonatal rat brain stem-spinal cord-bladder preparation

1994 ◽  
Vol 266 (3) ◽  
pp. R658-R667 ◽  
Author(s):  
K. Sugaya ◽  
W. C. De Groat
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Brain Stem ◽  
Rat Brain ◽  
Bladder Wall ◽  
Spinal Reflex ◽  
Neonatal Rat ◽  
Evoked Contractions ◽  
Stimulation Of

An in vitro neonatal (1-7 day) rat brain stem-spinal cord-bladder (BSB) preparation was used to examine the central control of micturition. Isovolumetric bladder contractions occurred spontaneously or were induced by electrical stimulation of the ventrolateral brain stem, spinal cord, bladder wall (ES-BW), or by perineal tactile stimulation (PS). Transection of the spinal cord at the L1 segment increased the amplitude of ES-BW- and PS-evoked contractions, and subsequent removal of the spinal cord further increased spontaneous and ES-BW-evoked contractions but abolished PS-evoked contractions. Hexamethonium (1 mM), a ganglionic blocking agent, mimicked the effect of cord extirpation. Tetrodotoxin (1 microM) blocked ES-BW- and PS-evoked contractions but enhanced spontaneous contractions. Bicuculline methiodide (10-50 microM), a gamma-aminobutyric acid A receptor antagonist, increased the amplitude of spontaneous, ES-BW- and PS-evoked contractions. These results indicate that PS-evoked contractions are mediated by spinal reflex pathways, whereas spontaneous and ES-BW-evoked contractions that are elicited by peripheral mechanisms are subject to a tonic inhibition dependent on an efferent outflow from the spinal cord. PS-evoked micturition is also subject to inhibitory modulation arising from sites rostral to the lumbosacral spinal cord. Although electrical stimulation of bulbospinal excitatory pathways can initiate bladder contractions in the neonatal rat, these pathways do not appear to have an important role in controlling micturition during the first postnatal week.

Excitation of lumbar motoneurons by the medial longitudinal fasciculus in the in vitro brain stem spinal cord preparation of the neonatal rat

1993 ◽  
Vol 70 (6) ◽  
pp. 2241-2250 ◽  
Author(s):  
M. K. Floeter ◽  
A. Lev-Tov
Keyword(s):  
Spinal Cord ◽  
Brain Stem ◽  
Short Latency ◽  
Medial Longitudinal Fasciculus ◽  
Paired Pulse ◽  
Long Latency ◽  
The Brain ◽  
Pulse Stimulation ◽  
Stimulation Of

1. The excitation of lumbar motoneurons by reticulospinal axons traveling in the medial longitudinal fasciculus (MLF) was investigated in the newborn rat using intracellular recordings from lumbar motoneurons in an in vitro preparation of the brain stem and spinal cord. The tracer DiI (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine) was introduced into the MLF of 6-day-old littermate rats that had been fixed with paraformaldehyde to evaluate the anatomic extent of this developing pathway. 2. Fibers labeled from the MLF by DiI were present in the cervical ventral and lateral white matter and a smaller number of labeled fibers extended to the lumbar enlargement. Patches of sparse terminal labeling were seen in the lumbar ventral gray. 3. In the in vitro preparation of the brain stem and spinal cord, MLF stimulation excited motoneurons through long-latency pathways in most motoneurons and through both short-(< 40 ms) and long-latency connections in 16 of 40 motoneurons studied. Short- and longer-latency components of the excitatory response were evaluated using mephenesin to reduce activity in polysynaptic pathways. 4. Paired-pulse stimulation of the MLF revealed a modest temporal facilitation of the short-latency excitatory postsynaptic potential (EPSP) at short interstimulus intervals (20–200 ms). Trains of stimulation at longer interstimulus intervals (1–30 s) resulted in a depression of EPSP amplitude. The time course of the synaptic depression was compared with that found in EPSPs resulting from paired-pulse stimulation of the dorsal root and found to be comparable. 5. The short-latency MLF EPSP was reversibly blocked by 6-cyano-7-nitroquinoxaline (CNQX), an antagonist of non-N-methyl-D-aspartate glutamate receptors, with a small CNQX-resistant component. Longer-latency components of the MLF EPSP were also blocked by CNQX, and some late components of the PSP were sensitive to strychnine. MLF activation of multiple polysynaptic pathways in the spinal cord is discussed.

Effect of stimulation of the dorsal aspect of the cervical spinal cord on ’Iocal cerebral blood flow and EEG in the cat

2000 ◽  
Vol 22 (4) ◽  
pp. 386-392 ◽  
Author(s):  
Masazumi Inoue ◽  
Hiroyuki Nakase ◽  
Hidehiro Hirabayashi ◽  
Toru Hoshida ◽  
Hoshida Toru ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cervical Spinal Cord ◽  
Dorsal Aspect ◽  
Stimulation Of
Sign in / Sign up

Export Citation Format

Share Document