Changes in somato-vesical reflexes during postnatal development in the kitten

DeGroat, William; Douglas, John; Glass, Jay D.; Simonds, William F.; Weimer, Bernal R.; Werner, Philipp

doi:10.1016/0006-8993(75)90884-7

Cited by 66 publications

(29 citation statements)

References 12 publications

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“…10 Evidence for the persistence of the perigenitalbladder reflex in MS animals was indicated by the volume voided and changes in reflex latency. Previous studies in kittens have shown that the latency of this reflex progressively increases with age, 3 which was also seen in the control group in this study (4.3 to 44 seconds from 2 days to 5 weeks). By comparison, in the MS group reflex latency decreased by almost 50% from 2 days to 3 weeks and it was more than 50% shorter than latency in control animals at 5 weeks.…”

Section: Discussionsupporting

confidence: 88%

“…3,5 In the MSPG group the bladders were manually emptied at 3 hours of separation but not prior to the return to the mother at 6 hours. Voided urine volume and perigenital-bladder reflex latency were recorded.…”

Section: Methodsmentioning

confidence: 99%

“…[1][2][3][4][5][6] After birth the rat pup cannot void spontaneously since voiding is controlled by the perigenital-bladder reflex, which is triggered by the mother licking the perigenital region of the pup. 2,4,6 The perigenital-bladder reflex is controlled by spinal mechanisms and it is essential for voiding because separation of the rat pup from its mother during the first 3 postnatal weeks leads to complete urinary retention.…”

Section: Introductionmentioning

confidence: 99%

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Maternal Separation Uncouples Reflex From Spontaneous Voiding in Rat Pups

Groat

2006

Journal of Urology

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Purpose-Rat pups only void when the perigenital-bladder reflex is activated by the mother rat licking the perineum. Maternal separation causes bladder distention as well as stress responses and anxiety behaviors in adult rats. We determined if MS would change voiding reflex maturation in neonatal rats.Materials and Methods-A total of 14 Sprague-Dawley rat pups were subjected to 6 hours of daily MS and 17 were subjected to 6 hours of MS with bladder emptying by perigenital stimulation at 3 hours on postnatal days 2 to 14. Age matched controls for the 2 groups remained with the mother. Spontaneous voiding in awake pups from 1 to 3 weeks was monitored in a metabolic cage and perigenital-bladder reflex latency was determined from 1 to 7 weeks. Cystometry was performed at 9 weeks with the rats under urethane anesthesia.Results-Spontaneous voiding began at 3 weeks in all animals. The latency of the perigenitalbladder reflex at 3 weeks was shorter than the latency at 2 days in MS animals (3.3 vs 6.4 seconds, p < 0.01) but not in control or MSPG animals. MS animals maintained the perigenital-bladder reflex 2 weeks longer than control animals. The spontaneous voiding behavior of MSPG animals was similar to that in controls.Conclusions-Intermittent bladder distention delays withdrawal of the spinal perigenitalbladder reflex but it does not affect maturation of the supraspinal bladder-bladder reflex that controls spontaneous voiding in older rats. This suggests that increased bladder afferent firing can selectively modulate spinal but not supraspinal mechanisms controlling postnatal changes in voiding function. Keywordsbladder; urination; maternal behavior; reflex; rats; Sprague-Dawley The neural mechanisms controlling bladder emptying undergo marked changes during the first 3 weeks of life in many mammals. [1][2][3][4][5][6] After birth the rat pup cannot void spontaneously since voiding is controlled by the perigenital-bladder reflex, which is triggered by the mother licking the perigenital region of the pup. 2,4,6 The perigenital-bladder reflex is controlled by spinal mechanisms and it is essential for voiding because separation of the rat pup from its mother during the first 3 postnatal weeks leads to complete urinary retention. 7,8 After 3 weeks of life the supraspinal bladder-bladder reflex by which bladder filling and emptying is controlled by the pons emerges, leading to spontaneous voiding. 9 Latency, or the duration of perigenital stimulation required to produce voiding, progressively lengthens as the perigenital-bladder reflex is down-regulated and it is eventually eliminated. 4,6 Electrophysiological studies in spinal slice preparations suggest that down-regulation of the perigenital-bladder reflex depends on input from the brain to the spinal cord and is associated with a decrease in spinal connections to parasympathetic PGNs. 10 We examined the influence of afferent input from the bladder on developmental changes in the perigenital-bladder and bladder-bladder reflexes in the neonatal rat. Increased af...

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Section: Discussionsupporting

confidence: 88%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Maternal Separation Uncouples Reflex From Spontaneous Voiding in Rat Pups

Groat

2006

Journal of Urology

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“…The high degree of variability associated with evoking this DNP mediated pudendo-vesicle reflex following SCT is in agreement with previous work (Boggs, et al, 2005,Boggs, et al, 2006) and provides evidence that both supraspinal (Aδ fiber) and spinal (c fiber) micturition pathways are involved (Mazieres, et al, 1998). In neonatal cats, this direct spinal pudendo-vesicle reflex is described as a mechanically induced perigenital reflex that facilitates bladder activity (DeGroat, et al, 1975). During maturation, a serotonergic descending inhibitory pathway masks this neonatal reflex , but the pathway re-emerges in the chronic SCI cat .…”

Section: Sustained Bladder Contractions Evoked By Pudendal Afferentssupporting

confidence: 90%

Bladder activation by selective stimulation of pudendal nerve afferents in the cat

Yoo

Woock

Grill

2008

Experimental Neurology

114

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Bladder contractions evoked by pudendal nerve stimulation in both spinal intact and spinal transected cats support the possibility of restoring urinary function in persons with chronic spinal cord injury (SCI). However, electrically evoked bladder responses in persons with SCI were limited to transient contractions at relatively low pressures. This prompted the present study, which presents a detailed quantification of the responses evoked by selective stimulation of individual branches of the pudendal nerve at different stimulation frequencies. In spinal intact cats anesthetized with α-chloralose, selective frequency dependent electrical activation of the sensory (2 Hz ≤ f ≤ 50 Hz), cranial sensory (f ≤ 5 Hz), dorsal genital (f ≥ 20 Hz) and rectal perineal (f ≤ 10 Hz) branches of the pudendal nerve evoked sustained bladder contractions dependent on the stimulation frequency. Contractions evoked by selective electrical stimulation resulted in significant increases in voiding efficiency compared to bladder emptying by distension evoked contractions (p ANOVA < 0.05). Acute spinal transection abolished reflex bladder contractions evoked by low frequency stimulation of the cranial sensory or rectal perineal branches, whereas contractions evoked by high frequency stimulation of the dorsal genital branch remained intact. This study presents evidence for two distinct micturition pathways (spino-bulbo-spinal vs. spinal reflexes) activated by selective afferent pudendal nerve stimulation, the latter of which may be applied to restore bladder function in persons with SCI. Keywords electrical stimulation; cranial sensory nerve; deep perineal branch; lower urinary tract physiology; external urethral sphincter; spinal cord injury; pudendo-pudendal reflex; spinal-bulbo-spinal; prostatic urethra; dorsal nerve of penis

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“…In spinal autonomic reflex pathways, synaptic refinement could be involved in the elimination of primitive segmental reflexes and the emergence of mature reflex patterns. In neonates of many species, excretory f unctions (micturition and defecation) are mediated exclusively by the segmental parasympathetic reflex pathway, which is activated when the mother licks the perineum of the neonate (Beach, 1966;de Groat et al, 1975;Thor et al, 1989). A few weeks after birth, this segmental reflex begins to disappear and is replaced by the newly developed spinobulbospinal reflex as the principal mechanism for excretion (de Groat, 1975;Fukuda et al, 1981;Kruse and de Groat, 1990;de Groat et al, 1993).…”

mentioning

confidence: 99%

Developmental Synaptic Depression Underlying Reorganization of Visceral Reflex Pathways in the Spinal Cord

Araki

Groat

1997

J. Neurosci.

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During development, neuronal connectivity has a remarkable plasticity. Synaptic refinement in the spinal autonomic nucleus might be involved in the elimination of primitive segmental reflexes and the emergence of mature spinobulbospinal reflexes, which occurs a few weeks after birth. To address this possibility, we examined the postnatal changes of segmental excitatory synaptic transmission by applying the whole-cell recording technique to parasympathetic preganglionic neurons in slice preparations of the rat lumbosacral spinal cord. The mean magnitude of unitary excitatory synaptic currents evoked in preganglionic neurons by stimulation of single interneurons remained unchanged during the first two postnatal weeks but was reduced by 50% during the third postnatal week. This reduction in synaptic efficacy was associated with a decrease in the amount of transmitter release from interneurons. Moreover, this developmental depression of segmental synaptic transmission was prevented by spinal cord transection at the thoracic level on postnatal day 14. Thus, developmental modification of excitatory synapses on preganglionic neurons appears to be attributable to competition between segmental interneuronal and descending bulbospinal inputs, which results in the developmental reorganization of parasympathetic excretory reflex pathways. Key words: synaptic plasticity; developmental synaptic depression; glutamatergic excitatory synaptic currents; spinal autonomic nucleus; parasympathetic preganglionic neurons; micturition reflex; chronic spinal transection; quantal analysisDuring early postnatal life, synaptic refinements are well known to occur in the central (Hubel and Wiesel, 1965;Mendell, 1984;Fregnac et al., 1988;Reiter and Stryker, 1988;Constantine-Paton et al., 1990) and peripheral (Redfern, 1970;Ridge and Betz, 1984;Dan and Poo, 1992;Balice-Gorden and Lichtman, 1994;Colman et al., 1997) nervous systems. This synaptic remodeling serves to refine initial coarse-grained and exuberant neuronal connections and results in formation of highly tuned neural circuits (Purves and Lichtman, 1985;Goodman and Shatz, 1993). In spinal autonomic reflex pathways, synaptic refinement could be involved in the elimination of primitive segmental reflexes and the emergence of mature reflex patterns. In neonates of many species, excretory f unctions (micturition and defecation) are mediated exclusively by the segmental parasympathetic reflex pathway, which is activated when the mother licks the perineum of the neonate (Beach, 1966;de Groat et al., 1975;Thor et al., 1989). A few weeks after birth, this segmental reflex begins to disappear and is replaced by the newly developed spinobulbospinal reflex as the principal mechanism for excretion (de Groat, 1975;Fukuda et al., 1981;Kruse and de Groat, 1990;de Groat et al., 1993). This is also a critical period for the establishment of synaptic refinements (Purves and Lichtman, 1985) as well as for the functional maturation of descending pathways to the spinal cord (Gilbert and Stelzner, 1979;Men...

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Changes in somato-vesical reflexes during postnatal development in the kitten

Cited by 66 publications

References 12 publications

Maternal Separation Uncouples Reflex From Spontaneous Voiding in Rat Pups

Maternal Separation Uncouples Reflex From Spontaneous Voiding in Rat Pups

Bladder activation by selective stimulation of pudendal nerve afferents in the cat

Developmental Synaptic Depression Underlying Reorganization of Visceral Reflex Pathways in the Spinal Cord

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