Brainstem loci for activation of electrodermal response in the cat

1975 ◽  
Vol 229 (4) ◽  
pp. 930-934 ◽  
Author(s):  
MA Davison ◽  
MC Koss
Keyword(s):  
Reticular Formation ◽  
Posterior Hypothalamus ◽  
Cervical Cord ◽  
Electrodermal Response ◽  
Posterior Commissure ◽  
Direct Stimulation ◽  
Electrodermal Responses ◽  
Decerebrate Cats ◽  
Dorsal Medulla ◽  
Stimulation Of

Brainstem loci from which electrodermal responses could be elicited were systematically explored by direct-stimulation techniques in chloralose-anesthetized and decerebrate cats. Reactive sites of the greatest amplitude were found to extend from the rostral border of the posterior hypothalamus, through the ventrolateral reticular formation of the pons and the medulla, to the cervical cord. Stimulation of these sites elicited stable, reproducible electrodermal responses of 10-30 mV in amplitude. In addition, it was found that stimulation of the ventrolateral extent of the lower brainstem evoked similar responses in the decerebrate preparation. Electrodermal responses could not be elicited from the dorsal medulla, the posterior commissure, or the midline region. The electrodermal response could be elicited from an apparently hypothalamus through the ventrolateral brainstem.

Reticular Formation Interactions

1958 ◽  
Vol 195 (1) ◽  
pp. 1-6 ◽  
Author(s):  
K. Koizumi ◽  
J. Ushiyama ◽  
C. McC. Brooks
Keyword(s):  
Auditory Cortex ◽  
Caudate Nucleus ◽  
Reticular Formation ◽  
Monosynaptic Reflex ◽  
Reflex Response ◽  
Direct Stimulation ◽  
Sensory Stimuli ◽  
Crus I ◽  
Evoked Activity ◽  
Stimulation Of

A comparison was made of the effects on the monosynaptic reflex and on unit discharge within the reticular formation of stimulating the reticular formation, the dentate nuclei, the paramedian lobe and crus I and II of the cerebellum, the caudate nucleus and the auditory cortex. Many reticular formation units were unaffected by the stimuli employed. The auditory cortex and caudate nucleus evoked activity in some reticular formation units without perceptible action on the monosynaptic reflex response. Stimulation of the cerebellum and dentate nuclei affected the reflex and was additive to the effects of reticular formation excitation. Cerebellar stimulation evoked activity in some reticular formation units, and inhibited that of others which were likewise inhibited by a variety of sensory stimuli. Some units were affected by one stimulus modality only but a few appeared to be under the influence of two centers, i.e. auditory cortex stimulation inhibited activity while caudate nucleus stimulation caused an augmentation of active firing. Direct stimulation of the reticular formation evoked shorter lasting activity of the elements in reticular formation than did stimulation of peripheral structures. The latencies of cerebellar effects on the reticular formation were often very long but the latencies of potentials evoked in the cerebellum by reticular formation stimuli were short.

An adrenergic basis for bulbar inhibition

1959 ◽  
Vol 197 (4) ◽  
pp. 835-838 ◽  
Author(s):  
J. I. Cranmer ◽  
A. W. Brann ◽  
L. M. N. Bach
Keyword(s):  
Reticular Formation ◽  
Intravenous Infusion ◽  
Regional Differences ◽  
Direct Injection ◽  
Inhibitory Effect ◽  
Direct Stimulation ◽  
Nucleus Reticularis ◽  
Nucleus Reticularis Gigantocellularis ◽  
Reticular Nuclei ◽  
Stimulation Of

Evidence has been obtained showing that intravenous infusion of Diebenzyline in cats anesthetized with Nembutal will consistently and completely abolish inhibition of the patellar reflex induced by direct stimulation of the bulbar reticular formation. The inhibition can always be restored by subsequent infusion of epinephrine. Parallel vasopressor effects can also be observed. Various techniques, including direct injection of Dibenzyline and epinephrine into the medulla through hollow electrodes, provided evidence that these drugs exerted depressant and enhancing effects, respectively, on the thresholds for bulbar inhibition. There appear to be regional differences in epinephrine sensitivity in the medulla. The area corresponding to the nucleus reticularis gigantocellularis appears to be more sensitive to epinephrine than surrounding reticular nuclei. The results suggest that locally released epinephrine activates the gigantocellularis nucleus which, in turn, develops a pattern of discharges leading to an inhibitory effect mediated by spinal projections. This mechanism may explain immobilization which frequently occurs in highly emotional situations.

Localization of central cardiovascular control mechanism in lower brain stem of the cat

1962 ◽  
Vol 202 (1) ◽  
pp. 25-30 ◽  
Author(s):  
C. Y. Chai ◽  
S. C. Wang
Keyword(s):  
Reticular Formation ◽  
Control Mechanism ◽  
Cardiac Responses ◽  
Pressor Responses ◽  
Efferent Pathways ◽  
Lower Brain Stem ◽  
The Right ◽  
Decerebrate Cats ◽  
Dorsal Medulla ◽  
Stereotaxic Technique

The lower brain stems of 42 vagotomized, midcollicular decerebrate cats under chloralose anesthesia were explored for vasomotor and cardiac responses by means of the stereotaxic technique. When a stimulus was given through bipolar coaxial electrodes with minute exposures at the tips, it was found possible to localize these responses in very discrete areas in the dorsal reticular formation and the adjacent periventricular gray. With current of slightly higher intensity, comparable responses could also be obtained in the ventrolateral reticular formation. It is suggested that the latter constitutes the hypothalamic efferent pathways, while responses from the dorsal medulla signal the activation of the bulbar pressor and cardioaccelerator mechanism. Further, pressor responses from the medulla on the right side are very often accompanied by marked cardioacceleration and only slight or moderate augmentation of cardiac contractions, whereas those from the left are accompanied by marked augmentation and moderate cardioacceleration. This finding suggests that the medullary sympathetic system descends predominately in the spinal cord of the homolateral side.

Failure of the Bulbar Inhibitory Reticular Formation to Affect Somatic Reflex Activity in the Unanesthetized Cat

1957 ◽  
Vol 190 (2) ◽  
pp. 330-332 ◽  
Author(s):  
A. J. Mandell ◽  
L. M. N. Bach
Keyword(s):  
Reticular Formation ◽  
Postoperative Recovery ◽  
Reflex Activity ◽  
Convulsive Activity ◽  
Direct Stimulation ◽  
Medullary Reticular Formation ◽  
Stimulating Electrodes ◽  
Stimulation Of ◽  
Nembutal Anesthesia

Bulbar inhibition of the patellar reflex was obtained under Nembutal anesthesia in cats at surgery when stimulating electrodes were implanted aseptically in the medullary reticular formation. After periods of 72–322 hours of postoperative recovery it was impossible to obtain inhibition of the patellar reflex even at stimulus voltages which produced convulsive activity. Reinduction of Nembutal anesthesia prior to killing always resulted in the reappearance of bulbar inhibition. Autonomic, respiratory and EEG desynchronization effects were always obtainable whether or not the animal was anesthetized. Etherized animals exhibited the usual bulbar inhibition of the patellar reflex, lost the inhibition when when removed from ether and regained the inhibition when re-anesthetized with ether. The authors conclude that either chemical (anesthetic) or surgical (decerebrate) removal of suprabulbar structures is required for the demonstration of bulbar reticular inhibition of the patellar reflex by direct stimulation of the reticular formation.

Central control of sympathetic cardiac augmentation in lower brain stem of the cat

1963 ◽  
Vol 205 (4) ◽  
pp. 749-753 ◽  
Author(s):  
C. Y. Chai ◽  
Norman N. Share ◽  
S. C. Wang
Keyword(s):  
Brain Stem ◽  
Carotid Arteries ◽  
Control Mechanism ◽  
Cardiovascular Responses ◽  
Central Control ◽  
Direct Stimulation ◽  
Vasomotor Reaction ◽  
Lower Brain Stem ◽  
Dorsal Medulla ◽  
Stimulation Of

Fifty-three vagotomized cats under chloralose were studied for cardiac augmentation, cardioacceleration, and vasomotor reaction on direct stimulation of the medulla oblongata and via reflex activations. Cardiac augmentation as well as other cardiovascular responses could be induced on stimulation of the dorsal medulla or the central cut end of the sciatic nerves, or on occlusion of the carotid arteries. The augmentation and other responses remained essentially unchanged regardless of the presence or absence of the rostral neural structures, including the hypothalamus. The results confirm and support the concept that a central control mechanism for vasomotor reaction and cardioacceleration as well as augmentation resides in the dorsal region of the lower brain stem.

scholarly journals The Role of BMP Signaling in Osteoclast Regulation

2021 ◽  
Vol 9 (3) ◽  
pp. 24
Author(s):  
Brian Heubel ◽  
Anja Nohe
Keyword(s):  
Bone Formation ◽  
Bone Morphogenetic Proteins ◽  
Bone Diseases ◽  
Bmp Signaling ◽  
Bone Homeostasis ◽  
Direct Stimulation ◽  
Federal Drug Administration ◽  
Bmp Pathway ◽  
Stimulation Of

The osteogenic effects of Bone Morphogenetic Proteins (BMPs) were delineated in 1965 when Urist et al. showed that BMPs could induce ectopic bone formation. In subsequent decades, the effects of BMPs on bone formation and maintenance were established. BMPs induce proliferation in osteoprogenitor cells and increase mineralization activity in osteoblasts. The role of BMPs in bone homeostasis and repair led to the approval of BMP2 by the Federal Drug Administration (FDA) for anterior lumbar interbody fusion (ALIF) to increase the bone formation in the treated area. However, the use of BMP2 for treatment of degenerative bone diseases such as osteoporosis is still uncertain as patients treated with BMP2 results in the stimulation of not only osteoblast mineralization, but also osteoclast absorption, leading to early bone graft subsidence. The increase in absorption activity is the result of direct stimulation of osteoclasts by BMP2 working synergistically with the RANK signaling pathway. The dual effect of BMPs on bone resorption and mineralization highlights the essential role of BMP-signaling in bone homeostasis, making it a putative therapeutic target for diseases like osteoporosis. Before the BMP pathway can be utilized in the treatment of osteoporosis a better understanding of how BMP-signaling regulates osteoclasts must be established.

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