Modulation of the spinobulbospinal micturition reflex pathway in cats

1992 ◽  
Vol 262 (3) ◽  
pp. R478-R484 ◽  
Author(s):  
M. N. Kruse ◽  
B. S. Mallory ◽  
H. Noto ◽  
J. R. Roppolo ◽  
W. C. de Groat
Keyword(s):  
Electrical Stimulation ◽  
Bladder Capacity ◽  
Recurrent Inhibition ◽  
Afferent Feedback ◽  
Descending Pathways ◽  
Reflex Pathway ◽  
Micturition Reflex ◽  
Long Duration ◽  
Cervical Stimulation ◽  
Stimulation Of

Micturition, which is mediated by a spinobulbospinal reflex pathway, can be modulated by various spinal and supraspinal mechanisms. This study examined modulation of the micturition reflex in decerebrate unanesthetized cats. Electrical stimulation of the pontine micturition center (PMC) elicited two types of bladder responses: small-amplitude short-duration responses due to direct activation of the bulbospinal pathway (PS-direct contractions) and large-amplitude long-duration reflex responses induced by PS-direct contractions but maintained by afferent feedback (PS-reflex contractions). Rectal and vaginal-cervical stimulation inhibited the PS-direct contractions, indicating inhibition of the descending or efferent limb of the micturition pathway. Stimulation of the central end of a transected S2 ventral root elicited recurrent inhibition of PS-reflex contractions but not of PS-direct contractions, indicating that recurrent inhibition does not directly affect the descending pathway. Continuous electrical stimulation (20 Hz) of the PMC decreased (53 +/- 21%) bladder capacity, presumably by affecting transmission in the pons or ascending input to the pons. Thus the micturition reflex could be modulated at several sites: the pons, the ascending or descending pathways, or spinal interneuronal sites.

Effects of WAY100635, a selective 5-HT1A-receptor antagonist on the micturition-reflex pathway in the rat

2001 ◽  
Vol 280 (5) ◽  
pp. R1407-R1413 ◽  
Author(s):  
Hidehiro Kakizaki ◽  
Mitsuharu Yoshiyama ◽  
Tomohiko Koyanagi ◽  
William C. De Groat
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Receptor Antagonist ◽  
Intrathecal Injection ◽  
Cervical Cord ◽  
Dependent Manner ◽  
Reflex Pathway ◽  
Micturition Reflex ◽  
Female Wistar Rats ◽  
Stimulation Of

5-Hydroxytryptamine (5-HT) receptors in the central nervous system have been implicated in the control of micturition. The present study was undertaken to evaluate the effects of a selective 5-HT1A-receptor antagonist { N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]- N-(2-pyridinyl)cyclohexanecarboxamide trihydrochloride (WAY100635)} on the micturition-reflex pathway in urethane-anesthetized female Wistar rats. Rhythmic isovolumetric bladder contractions evoked by bladder distension were abolished by 0.3- to 3-mg/kg iv or 30- to 100-μg intrathecal (it) administration of WAY100635 in a dose-dependent manner for periods of 3–15 min. Intrathecal injection of WAY100635 was effective only if injected at the L6-S1 spinal cord level, but not at the thoracic or cervical cord levels. WAY100635 (30–100 μg it) significantly reduced the amplitude of bladder contractions evoked by electrical stimulation of the pontine micturition center. However, the field potentials in the rostral pons evoked by electrical stimulation of pelvic nerve were not affected by intrathecal or intravenous injection of WAY100635. These results suggest that 5-HT1A receptors at the L6-S1 level of the spinal cord have an important role in the tonic control of the descending limb of the micturition-reflex pathway in the rat.

scholarly journals Activation and inhibition of the micturition reflex by penile afferents in the cat

2008 ◽  
Vol 294 (6) ◽  
pp. R1880-R1889 ◽  
Author(s):  
John P. Woock ◽  
Paul B. Yoo ◽  
Warren M. Grill
Keyword(s):  
Electrical Stimulation ◽  
De Novo ◽  
Bladder Capacity ◽  
Functional Restoration ◽  
External Urethral Sphincter ◽  
Micturition Reflex ◽  
Cuff Electrode ◽  
Evoked Contractions ◽  
Stimulation Of ◽  
40 Hz

Coordination of the urinary bladder and the external urethral sphincter is controlled by descending projections from the pons and is also subject to modulation by segmental afferents. We quantified the effects on the micturition reflex of sensory inputs from genital afferents traveling in the penile component of the somatic pudendal nerve by electrical stimulation of the dorsal nerve of the penis (DNP) in α-chloralose anesthetized male cats. Depending on the frequency of stimulation (range, 1–40 Hz), activation of penile afferents either inhibited contractions of the bladder and promoted urine storage or activated the bladder and produced micturition. Stimulation of the DNP at 5–10 Hz inhibited distension-evoked contractions and increased the maximum bladder capacity before incontinence. Conversely, stimulation at 33 and 40 Hz augmented distension-evoked contractions. When the bladder was filled above a threshold volume (70% of the volume necessary for distension-evoked contractions), stimulation at 20–40 Hz activated de novo the micturition reflex and elicited detrusor contractions that increased voiding efficiency compared with distension-evoked voiding. Electrical stimulation of the DNP with a cuff electrode or percutaneous wire electrode produced similar results. The ability to evoke detrusor contractions by activation of the DNP was preserved following acute spinal cord transection. These results demonstrate a clear role of genital afferents in modulating the micturition reflex and suggest the DNP as a potential target for functional restoration of bladder control using electrical stimulation.

Epidural Electrical Stimulation on Neurogenic Bladder

1993 ◽  
Vol 60 (1) ◽  
pp. 87-89 ◽  
Author(s):  
C. Simeone ◽  
E. Frego ◽  
T. Zanotelli ◽  
R. Capra ◽  
A. Lenzi ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Beneficial Effect ◽  
Bladder Dysfunction ◽  
Bladder Capacity ◽  
Bladder Function ◽  
Complete Relief ◽  
Detrusor Sphincter Dyssynergia ◽  
Thoracic Level ◽  
Stimulation Of

In 1967 Shealy first used electrical stimulation of the spinal cord to treat spasticity and pain. This therapy proved to be effective for bladder dysfunction too. The effect of electrical stimulation of the spinal cord at thoracic level has been evaluated in 18 neurogenic patients suffering from hyperreflexia with detrusor-sphincter dyssynergia. Bladder function improved significantly in 13 (73%). Partial or complete relief of bladder hyperreflexia, marked increased of bladder capacity and reduction of residual urine were recorded. The beneficial effect of stimulation indicates that it is a safe and effective alternative treatment for the neuropathic bladder and careful trials with further investigations should be carried out.

Electrical Stimulation of Somatic Afferent Nerves in the Foot Increases Bladder Capacity in Healthy Human Subjects

2014 ◽  
Vol 191 (4) ◽  
pp. 1009-1013 ◽  
Author(s):  
Mang L. Chen ◽  
Christopher J. Chermansky ◽  
Bing Shen ◽  
James R. Roppolo ◽  
William C. de Groat ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Human Subjects ◽  
Bladder Capacity ◽  
Healthy Human ◽  
Afferent Nerves ◽  
Healthy Human Subjects ◽  
Stimulation Of

scholarly journals The Dorsomedial Hypothalamic Nucleus In Autonomic And Neuroendocrine Homeostasis

1975 ◽  
Vol 2 (1) ◽  
pp. 45-60 ◽  
Author(s):  
Lee L. Bernardis
Keyword(s):  
Growth Hormone ◽  
Electrical Stimulation ◽  
Food Intake ◽  
Present Report ◽  
Hypothalamic Nucleus ◽  
Control Mechanisms ◽  
Storage Site ◽  
Dorsomedial Hypothalamic Nucleus ◽  
Cervical Stimulation ◽  
Stimulation Of

SUMMARY:Median eminence and ventromedial hypothalamus have in the past been the principal foci of research in neuroendocrine and neurovisceral control mechanisms. The present report provides an overview of work involving the dorsomedial hypothalamic nucleus (DMN). This structure is located dorsal to the ventromedial hypothalamic nucleus (VMN) and extends anteroposteriorly from the plane of the largest cross section of the VMN to the plane of the dorsal premammillary nucleus. Fibers from the DMN pass with the periventricular system and the dorsal longitudinal fasciculus of Schütz and have been traced to the midbrain tegmentum and reticular formation. Intrahypothalamic connections involve intensive networks between DMN, lateral hypothalamic nucleus (LHN) and VMN. Regarding neurotransmitters, recent studies indicate that the DMN receives noradrenergic innervation along two pathways, a dorsal and a ventral one. Monoamine-containing systems approach the DMN from the lateral hypothalamus and the bulk of these fibers are carried in the medium forebrain bundle from their cells of origin in the brain stem. Studies of the vascular supply indicate that both VMN and DMN receive their blood supply from the internal carotid artery. It has been recently demonstrated that the DMN is involved in the control of food intake and possibly water intake as well. Discrete lesions in the DMN have caused hypophagia and hypodipsia, and implantation of epinephrine and norepinephrine in this area has initiated eating. Many years ago, electrical stimulation of this area was reported to cause eating. Although DMN lesions cause hypodipsia, they do not result in the reduced water/food intake ratios that are so characteristic of the VMN syndrome. DMN lesions are also followed by reduced spontaneous activity (running wheel), but this reduced activity is not accompanied by increased weight gain and accretion of adipose tissue, the latter being consistently observed in the VMN rat. Rather, carcass fat remains normal in the DMN rat and carcass protein is either normal or slightly increased. Many of the aforementioned changes in weanling rats with DMN lesions, however, are not matched by similar alterations in the intermediary metabolism of carbohydrate and lipid. Possibly this is due to a “resetting” of a central autonomic control system that makes it possible for the DMN rat to adapt more efficiently to a reduced influx of substrate, i.e. the consistent hypophagia. From a review of the literature it appears that the DMN and their circuitry are involved in only a few neuroendocrine, i.e. hypothalamohypophyseal control mechanisms. Both lesion and cervical stimulation experiments suggest an involvement of the DMN in the control of LTH. Circumstantial evidence points to the DMN as a possible formation and/or storage site of growth hormone inhibiting factor (GIF). Although DMN rats show reduced ponderal and linear growth, they have been found to have normal or elevated plasma growth hormone (GH) levels. Both lesion and stimulation studies have yielded the impression that the DMN is not involved in thyroid, i.e., thyrotropin stimulating hormone releasing factor (TSHRF) control. Electrical stimulation of the DMN has been reported to result in a positive correlation between adrenal blood flow and adrenal corticoid release in hypophysectomized dogs. This has been interpreted as a coordinated response at the level of a “dorsomedial sympathetic vasodilator relay” rather than a “true” neuroendocrine effect via corticotropin releasing factor (CRF). Experiments that failed to demonstrate a relationship between the DMN and the tonic and cyclic control of luteinizing hormone releasing factor (LHRF) are discussed. The data reviewed indicate the existence in the dorsomedial hypothalamus of an area that exerts a profound influence on many aspects of neurovisceral and some neuroendocrine control systems.

DETERMINATION OF THE DETAILED HYPOTHALAMIC ROUTE OF THE MILK-EJECTION REFLEX IN THE GUINEA-PIG

1971 ◽  
Vol 50 (1) ◽  
pp. 135-152 ◽  
Author(s):  
J. S. TINDAL ◽  
G. S. KNAGGS
Keyword(s):  
Electrical Stimulation ◽  
Lateral Hypothalamus ◽  
Third Ventricle ◽  
Milk Ejection ◽  
Lateral Direction ◽  
Reflex Pathway ◽  
Oxytocin Release ◽  
Far Lateral ◽  
Milk Ejection Reflex ◽  
Stimulation Of

SUMMARY The effect of various types of surgical damage to the forebrain on the release of oxytocin in response to electrical stimulation of the discrete ascending milk-ejection reflex pathway in the mid-brain was investigated in 99 anaesthetized lactating guinea-pigs. Oxytocin release was measured by comparison of experimental milk-ejection responses with the response to i.v. injection of known amounts of synthetic oxytocin. Removal of the entire telencephalon, including cerebral cortex, hippocampi, amygdalae and forebrain rostral to the hypothalamus, did not affect the subsequent release of oxytocin after electrical stimulation of the pathway in the mid-brain, from which it was concluded that the reflex pathway within the forebrain is entirely diencephalic. Transection of the hypothalamus immediately rostral to the paraventricular (PV) nuclei was without effect, while transection immediately caudal to the PV nuclei blocked the release of oxytocin. Destruction of the PV nuclei by a radiofrequency lesion which spared the supraoptic (SO) nuclei blocked the release of oxytocin. Undercutting both PV nuclei so as to isolate them from the ventral hypothalamus blocked the release of oxytocin. Undercutting the PV nucleus ipsilateral to the stimulated side of the mid-brain blocked the release of oxytocin, while undercutting the contralateral PV nucleus had no effect. The PV nuclei, therefore, lie on the ascending path of the milk-ejection reflex, the SO nuclei do not, and, from the mid-brain forwards, the ascending pathway remains uncrossed. The course of the reflex pathway was traced rostrally from the mesodiencephalic junction by making narrow transverse knife-cuts and determining which cuts reduced or blocked the release of oxytocin after mid-brain stimulation. At this level, the pathway on each side of the brain is represented by separate dorsal and ventral paths and in the present study it was found that the ventral path is more important than the dorsal path in terms of oxytocin release. The ventral path passes forward in the medial forebrain bundle, in the far-lateral hypothalamus, while the dorsal path enters the posterior hypothalamus dorsally in the periventricular region at the top of the third ventricle and impinges on the thalamic reuniens nucleus. Shortly afterwards the dorsal path swings abruptly in the lateral direction to join the ventral path in the lateral hypothalamus. The reunited pathway then moves forward in this position until it is level with the PV nuclei, where it swings dorsomedially to relay with the lateral tip of the ipsilateral PV nucleus, and in doing so intermingles with the descending neurosecretory fibres from this nucleus.

Neural pathways involved in sacral neuromodulation of reflex bladder activity in cats

2013 ◽  
Vol 304 (6) ◽  
pp. F710-F717 ◽  
Author(s):  
Fan Zhang ◽  
Shouguo Zhao ◽  
Bing Shen ◽  
Jicheng Wang ◽  
Dwight E. Nelson ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Sacral Neuromodulation ◽  
Bladder Capacity ◽  
Inhibitory Effect ◽  
Ventral Root ◽  
Neural Pathways ◽  
Descending Pathways ◽  
The Central Nervous System ◽  
Bladder Activity ◽  
Stimulation Of

This study examined the mechanisms underlying the effects of sacral neuromodulation on reflex bladder activity in chloralose-anesthetized cats. Bladder activity was recorded during cystometrograms (CMGs) or under isovolumetric conditions. An S1–S3 dorsal (DRT) or ventral root (VRT) was electrically stimulated at a range of frequencies (1–30 Hz) and at intensities relative to threshold (0.25–2T) for evoking anal/toe twitches. Stimulation of DRTs but not VRTs at 1T intensity and frequencies of 1–30 Hz inhibited isovolumetric rhythmic bladder contractions. A 5-Hz DRT stimulation during CMGs was optimal for increasing ( P < 0.05) bladder capacity (BC), but stimulation at 15 and 30 Hz was ineffective. Stimulation of the S1 DRT was more effective (increases BC to 144% and 164% of control at 1T and 2T, respectively) than S2 DRT stimulation (increases BC to 132% and 150% of control). Bilateral transection of the hypogastric or pudendal nerves did not change the inhibitory effect induced by S1 DRT stimulation. Repeated stimulation of S1 and S2 DRTs during multiple CMGs elicited a significant ( P < 0.05) increase in BC (to 155 ± 11% of control) that persisted after termination of the stimulation. These results in cats suggest that the inhibition of reflex bladder activity by sacral neuromodulation occurs primarily in the central nervous system by inhibiting the ascending or descending pathways of the spinobulbospinal micturition reflex.

Fictive cough in the cat

1991 ◽  
Vol 71 (6) ◽  
pp. 2325-2331 ◽  
Author(s):  
D. C. Bolser
Keyword(s):  
Electrical Stimulation ◽  
Mechanical Stimulation ◽  
Large Amplitude ◽  
Superior Laryngeal Nerve ◽  
Laryngeal Nerve ◽  
Afferent Feedback ◽  
Respiratory Cycle ◽  
Decerebrate Cats ◽  
Stimulation Of

Experiments were performed to determine whether cough could be elicited in paralyzed cats ventilated on a respiratory cycle-triggered pump. Midcollicular decerebrate cats were paralyzed and artificially ventilated on a phrenic-triggered pump. Phrenic and cranial iliohypogastric nerve efferent activities were recorded. Cough was elicited by electrical stimulation of the superior laryngeal nerve (SLN) or probing the intrathoracic trachea. Fictive coughs induced by electrical stimulation of the SLN or mechanical stimulation of the intrathoracic trachea consisted of large-amplitude bursts in phrenic discharge immediately followed by large bursts in cranial iliohypogastric discharge. During fictive cough, phrenic postinspiratory discharge was reduced relative to control cycles. Codeine (0.03–1 mg/kg iv) decreased both SLN- and probe-induced fictive cough. I conclude that fictive cough can be produced in paralyzed cats ventilated on a phrenic-triggered pump. Furthermore, fictive cough can be produced in the absence of afferent feedback associated with active expiration.

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