The role of neuropeptides in the sacral autonomic reflex pathways of the cat

1983 ◽  
Vol 7 (3-4) ◽  
pp. 339-350 ◽  
Author(s):  
W.C. de Groat ◽  
M. Kawatani ◽  
T. Hisamitsu ◽  
I. Lowe ◽  
C. Morgan ◽  
...  
Keyword(s):  
Reflex Pathways ◽  
Autonomic Reflex

Role of the medullary lateral tegmental field in reflex-mediated sympathoexcitation in cats

2004 ◽  
Vol 286 (3) ◽  
pp. R451-R464 ◽  
Author(s):  
Hakan S. Orer ◽  
Gerard L. Gebber ◽  
Shaun W. Phillips ◽  
Susan M. Barman
Keyword(s):  
Nmda Receptor ◽  
Nmda Receptors ◽  
Receptor Antagonist ◽  
Sympathetic Nerve Activity ◽  
Nmda Receptor Antagonist ◽  
Vagal Afferents ◽  
Reflex Pathways ◽  
Excitatory Responses ◽  
Stimulation Of

We tested the hypothesis that blockade of N-methyl-d-aspartate (NMDA) and non-NMDA receptors on medullary lateral tegmental field (LTF) neurons would reduce the sympathoexcitatory responses elicited by electrical stimulation of vagal, trigeminal, and sciatic afferents, posterior hypothalamus, and midbrain periaqueductal gray as well as by activation of arterial chemoreceptors with intravenous NaCN. Bilateral microinjection of a non-NMDA receptor antagonist into LTF of urethane-anesthetized cats significantly decreased vagal afferent-evoked excitatory responses in inferior cardiac and vertebral nerves to 29 ± 8 and 24 ± 6% of control ( n = 7), respectively. Likewise, blockade of non-NMDA receptors significantly reduced chemoreceptor reflex-induced increases in inferior cardiac (from 210 ± 22 to 129 ± 13% of control; n = 4) and vertebral nerves (from 253 ± 41 to 154 ± 20% of control; n = 7) and mean arterial pressure (from 39 ± 7 to 21 ± 5 mmHg; n = 8). Microinjection of muscimol, but not an NMDA receptor antagonist, caused similar attenuation of these excitatory responses. Sympathoexcitatory responses to the other stimuli were not attenuated by microinjection of a non-NMDA receptor antagonist or muscimol into LTF. In fact, excitatory responses elicited by stimulation of trigeminal, and in some cases sciatic, afferents were enhanced. These data reveal two new roles for the LTF in control of sympathetic nerve activity in cats. One, LTF neurons are involved in mediating sympathoexcitation elicited by activation of vagal afferents and arterial chemoreceptors, primarily via activation of non-NMDA receptors. Two, non-NMDA receptor-mediated activation of other LTF neurons tonically suppresses transmission in trigeminal-sympathetic and sciatic-sympathetic reflex pathways.

Changes in Transmission in Some Reflex Pathways During Movement in Humans

Physiology ◽  
1989 ◽  
Vol 4 (1) ◽  
pp. 29-32
Author(s):  
E Fournier ◽  
P-D Emmanuel
Keyword(s):  
Functional Role ◽  
Voluntary Movement ◽  
Spinal Pathways ◽  
Reflex Pathways ◽  
Spinal Circuitry ◽  
Human Experiments

The gain of the monosynaptic stretch rerflex is controlled by many spinal pathways. Only human experiments allow the exploration of changes in transmission in these pathways during voluntary movement. Unexpected results have been obtained, which have led to new conceptions concerning the functional role of the spinal circuitry.

scholarly journals Role of p75NTR in female rat urinary bladder with cyclophosphamide-induced cystitis

2008 ◽  
Vol 295 (6) ◽  
pp. F1778-F1789 ◽  
Author(s):  
Mary Beth Klinger ◽  
Margaret A. Vizzard
Keyword(s):  
Urinary Bladder ◽  
Intravesical Instillation ◽  
Bladder Function ◽  
Neurotrophin Receptor ◽  
P75 Neurotrophin Receptor ◽  
Female Rat ◽  
Rat Urinary Bladder ◽  
Micturition Reflex ◽  
Reflex Pathways

Previous studies demonstrated changes in urinary bladder neurotrophin content and upregulation of neurotrophin receptors, TrkA and the p75 neurotrophin receptor (p75NTR), in micturition reflex pathways after cyclophosphamide (CYP)-induced cystitis. p75NTR can bind nerve growth factor (NGF) and modulate NGF-TrkA binding and signaling. We examined p75NTR expression and the role of p75NTR in the micturition reflex in control and CYP-treated rats. p75NTR Immunoreactivity was present throughout the urinary bladder. CYP-induced cystitis (4 h, 48 h, chronic) increased ( P ≤ 0.05) p75NTR expression in whole urinary bladder as shown by Western blotting. The role of p75NTR in bladder function in control and CYP-treated rats was determined using conscious cystometry and immunoneutralization or PD90780, a compound known to specifically block NGF binding to p75NTR. An anti-p75NTR monoclonal antibody or PD90780 was infused intravesically and cystometric parameters were evaluated. Both methods of p75NTR blockade significantly ( P ≤ 0.05) decreased the intercontraction interval and void volume in control and CYP-treated rats. Intravesical infusion of PD90780 also significantly ( P ≤ 0.001) increased intravesical pressure and increased the number of nonvoiding contractions during the filling phase. Control intravesical infusions of isotype-matched IgG and vehicle were without effect. Intravesical instillation of PD90780 significantly ( P ≤ 0.01) reduced the volume threshold to elicit a micturition contraction in control rats (no inflammation) and CYP-treated in a closed urinary bladder system. These studies demonstrate 1) ubiquitous p75NTR expression in urinary bladder and increased expression with CYP-induced cystitis and 2) p75NTR blockade at the level of the urinary bladder produces bladder hyperreflexia in control and CYP-treated rats. The overall activity of the urinary bladder reflects the balance of NGF-p75NTR and NGF-TrkA signaling.

Rehabilitating the neurogenic bladder: The role of artificial neural reflex pathways in children with spina bifida

2006 ◽  
Vol 7 (2) ◽  
pp. 133-135
Author(s):  
Sarah M. Lambert ◽  
Kenneth I. Glassberg ◽  
Richard C. Anderson
Keyword(s):  
Spina Bifida ◽  
Neurogenic Bladder ◽  
Reflex Pathways ◽  
Artificial Neural

scholarly journals Neural Mechanisms of Cardioprotection

Physiology ◽  
2014 ◽  
Vol 29 (2) ◽  
pp. 133-140 ◽  
Author(s):  
Andrey Gourine ◽  
Alexander V. Gourine
Keyword(s):  
Myocardial Infarction ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Neural Mechanisms ◽  
Vagal Activity ◽  
Remote Ischemic Conditioning ◽  
Ischemic Conditioning ◽  
Reflex Pathways ◽  
Autonomic Reflex

This review highlights the importance of neural mechanisms capable of protecting the heart against lethal ischemia/reperfusion injury. Increased parasympathetic (vagal) activity limits myocardial infarction, and recent data suggest that activation of autonomic reflex pathways contributes to powerful innate mechanisms of cardioprotection underlying the remote ischemic conditioning phenomena.

scholarly journals Role of L-DOPA in Spinal Nociceptive Reflex Activity: Higher Sensitivity of Aδ Versus C Fibre-Evoked Nociceptive Reflexes to L-DOPA

2011 ◽  
pp. 701-703
Author(s):  
E. D. SCHOMBURG ◽  
P. DIBAJ ◽  
H. STEFFENS
Keyword(s):  
Radiant Heat ◽  
Reflex Activity ◽  
Late Component ◽  
Early Component ◽  
Nociceptive Reflex ◽  
Reflex Pathways ◽  
Nociceptive Reflexes ◽  
C Fibre ◽  
Higher Sensitivity

The role of L-DOPA in spinal nociceptive reflex activity has been re-evaluated. In high spinal cats, with supraspinal loops being excluded, the onset of reflex facilitation induced by noxious radiant heat is delayed after injection of L-DOPA by 4 to 10 s, i.e. the early component of nociceptive reflex facilitation is blocked, while the late component persisted. Further investigations have shown that the early component of reflex facilitation induced by noxious radiant heat is mediated by Aδ-fibres and the late component by C-fibres. Therefore, it can be assumed that L-DOPA, like opioids, preferentially blocks the transmission in nociceptive reflex pathways from Aδ-fibres.

scholarly journals The biological clock in cluster headache: A review and hypothesis

Cephalalgia ◽  
2019 ◽  
Vol 39 (14) ◽  
pp. 1855-1866 ◽  
Author(s):  
Willemijn C Naber ◽  
Rolf Fronczek ◽  
Joost Haan ◽  
Patty Doesborg ◽  
Christopher S Colwell ◽  
...  
Keyword(s):  
Cluster Headache ◽  
Sleep Stage ◽  
Seasonal Pattern ◽  
Biological Clock ◽  
Clear Correlation ◽  
Cluster Headache Attack ◽  
Autonomic Reflex ◽  
Role Of Light ◽  
Light Sleep

Objective To review and discuss the putative role of light, sleep, and the biological clock in cluster headache. Discussion Cluster headache attacks are believed to be modulated in the hypothalamus; moreover, the severe pain and typical autonomic cranial features associated with cluster headache are caused by abnormal activity of the trigeminal-autonomic reflex. The temporal pattern of cluster headache attacks suggests involvement of the biological clock, and the seasonal pattern is influenced by the number of daylight hours. Although sleep is often reported as a trigger for cluster headache attacks, to date no clear correlation has been established between these attacks and sleep stage. Conclusions We hypothesize that light, sleep, and the biological clock can change the brain’s state, thereby lowering the threshold for activating the trigeminal-autonomic reflex, resulting in a cluster headache attack. Understanding the mechanisms that contribute to the daily and seasonal fluctuations in cluster headache attacks may provide new therapeutic targets.

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