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Robert M. Levin - One of the best experts on this subject based on the ideXlab platform.
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comparison of urinary bladder function in 6 and 24 month male and female rats
The Journal of Urology, 1992Co-Authors: Penelope A. Longhurst, Berit Eika, Robert E. Leggett, Robert M. LevinAbstract:Abstract Micturition characteristics, collagen composition, and in vitro urinary bladder strip contractility were examined in young adult (six month) and old (24 month) male and female Fischer 344 rats. Although young female rats consumed significantly less water than young males, there were no differences in volumes of urine excreted. Old females excreted significantly more urine than old males, but there were no differences in volumes of water consumed. Old male rats had similar Micturition frequencies during the light and dark cycles, in contrast to females and young males, where the number of Micturitions during the dark cycle was significantly greater than those during the light cycle. The mean and maximal Micturition volumes were significantly greater in old males compared to young males and old females during both the light and dark cycles. Bladders from female rats weighed significantly less than bladders from males of the same age, and the bladders from young rats weighed less than those of old rats. The protein and collagen concentrations were significantly less in bladder bodies from young females than old females. The amount of collagen resistant to digestion by Pronase, and thus thought to be cross-linked, was significantly greater in bladders from old rats compared to young. No differences between groups were found in the contractile responses of bladder base strips. There were trends for the absolute contractile responses of bladder body strips from old males to field stimulation, carbachol, ATP, and KCl to be larger than the other groups, and for strips from the young females to be smaller. The responses of strips from young females to field stimulation and KCl were significantly less than those of young males or old females, and responses to 10~3 M ATP were less than those of old females. Responses of strips from old males to 60 mM KC1 were significantly greater than those of young males. The differences in contractility could be attributed to the differences in strip mass. It appears, therefore, that urinary bladder function in male and female rats is unaffected by increasing age between 6 and 24 months.
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the influence of ovariectomy and estradiol replacement on urinary bladder function in rats
The Journal of Urology, 1992Co-Authors: Penelope A. Longhurst, Jane Kauer, Robert E. Leggett, Robert M. LevinAbstract:Abstract Female Fischer 344 rats were ovariectomized or sham operated and treated with oil or estradiol cypionate (100 mg./100 gm./month) for two or four months. Rats were then placed in metabolism cages for measurement of Micturition characteristics, and bladders were removed for bladder strip studies. Ovariectomy had no effects on Micturition characteristics. However, estradiol treatment of ovariectomized rats caused significant increases in water consumption and urine excretion, and in mean and maximal Micturition volumes compared to both ovariectomized and sham-operated rats. These effects were more pronounced at four months. Estradiol treatment also caused significant increases in bladder body mass, while ovariectomy was without effect. Two months after ovariectomy and/or estradiol treatment, there were no differences in contractile responses of bladder body or base strips to contractile agents when compared to shams. However, after four months, ovariectomy caused significant decreases in contractile responsiveness to nerve stimulation, ATP, carbachol, and KCl compared to sham-operated rats. Estradiol treatment caused increased responsiveness to nerve stimulation, ATP, carbachol, and KCl compared to ovariectomized rats, and to carbachol compared to sham operated rats. Possible causes for the effects of ovariectomy on bladder contractility include decreases in calcium influx. Although estradiol reversed the effects of ovariectomy on bladder function, in addition we observed some indirect effects which were probably the result of estradiol-induced polyuria and increases in bladder mass.
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effects of sensitization on female guinea pig urinary bladder function in vivo and in vitro studies
The Journal of Urology, 1991Co-Authors: Alan J. Wein, Penelope A. Longhurst, Robert M. LevinAbstract:Abstract Although bladder inflammation is known clinically to produce a variety of symptoms including urgency, frequency, and pain, there are only a few experimental studies that directly relate bladder inflammation with urodynamic and functional alterations. We have used the sensitized guinea pig model to study the effects of inflammation on Micturition parameters, cystometry, and in vitro bladder contractility. This model depends on the allergic response of the bladder mucosa to ovalbumin, an otherwise non-irritative agent, as an antigen. In vivo exposure of the bladder to ovalbumin via urethral catheterization induced a prompt and marked increase in the number of Micturitions in antigen-sensitized guinea pigs. Ovalbumin had no effects on the Micturition parameters in the control group. Using in vivo cystometry, intravesical exposure to ovalbumin induced a significant decrease in both the pressure at which Micturition was induced, and the volume at which Micturition was induced. Ovalbumin had no effect on cystometric parameters of the control animals. In vitro exposure of whole-bladder preparations to ovalbumin induced a significant contractile response only in the bladders isolated from the sensitized guinea pigs. The responses of the isolated bladders to field stimulation and bethanechol were identical for bladders from both sensitized and control animals. In conclusion, exposure of the bladder to ovalbumin in the sensitized animal induced an increase in the frequency of Micturitions and a decrease in the pressure and volume at which Micturition was induced. Thus, intravesical exposure of the bladder mucosa to a substance that the bladder has been sensitized to can induce alterations in Micturition that are consistent with the clinical symptoms of “urgency and frequency”.
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comparison of urinary bladder function in sexually mature and immature male and female rats
The Journal of Urology, 1990Co-Authors: Alexa L. Chun, Alan J. Wein, Richard C Harkaway, Robert M. LevinAbstract:Abstract Although studies exist using both male and female rats, there are virtually no studies that compare male and female bladder function. In this initial study, in-vivo and in-vitro urinary bladder function was investigated in two age groups of male and female rats (sexually immature and sexually mature). These studies compare in-vivo Micturition behavior (water intake, urine output, frequency and volume per Micturition); and in-vitro whole bladder function (bladder volume/pressure relationships, the ability of the in-vitro bladders to generate pressure and empty in response to bethanechol and field stimulation). The results can be summarized as follows: 1) The 24 hour water intake, urine output, and volume per Micturition for the mature male rats was significantly greater than that of the mature females with no significant differences among the immature females, mature females, or immature males. 2) There were no significant differences in the frequency of Micturition between the 4 groups. 3) Although the average plateau pressures (cystometrograms) of the immature and mature female bladders were greater than that of the immature and mature male bladders, the compliance was similar for all groups. 4) The maximum pressure response of the mature female bladder was significantly greater than pressures generated by bladders in the other three groups; there were no age or sex related differences in the bethanechol log ED50 values. 5) There were no age or sex-related differences in the bethanechol log ED50 values or maximal expulsion responses. 6) Field stimulated bladders from mature animals generated significantly greater intravesical pressures than bladders from immature animals, but, there were no significant differences in maximal pressures attained between mature male and female bladders nor between immature male and female bladders. In conclusion, Micturition behavior, and the maximal pressure response to bethanechol changed dramatically with sexual maturity. These results are consistent with the idea that estrogen and other hormones may have a marked influence on bladder function and Micturition behavior. (J. Urol, 143: 1267–1271, 1990)
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in vivo urinary bladder function in rats following prolonged diabetic and non diabetic diuresis
Neurourology and Urodynamics, 1990Co-Authors: Penelope A. Longhurst, Alan J. Wein, Robert M. LevinAbstract:Changes in urinary bladder function are present in animal models of diabetes mellitus. In vivo cystometry in diabetic rats shows a bladder with increased capacity and a raised threshold for initiation of the Micturition reflex. At sacrifice, diabetic rats have bladder hypertrophy, resulting in approximately a doubling of the bladder weight. This study was designed to characterize the effects of diabetes on Micturition in the streptozotocin-diabetic rat. For comparative purposes, two different control groups were examined: 1) age-matched control rats and 2) age-matched rats which were given 5% sucrose to drink. Sucrose-fed rats consumed large volumes of fluid resulting in diuresis and bladder hypertrophy. Fluid consumption and excretion were significantly increased in diabetic and sucrose-drinking rats. In addition, the diabetic rats both drank and excreted more than the sucrose-drinking rats. Control rats had twice as many Micturitions during the dark cycle than during the light cycle, but the volume Micturition during the dark cycle was less than one-half the volume per Micturition during the light cycle. Sucrose drinking rats had the same number of Micturitions as control rats during the light cycle. but the volumes per Micturition were significantly increased. During the dark cycle, the number of Micturitions increased four-fold and the volume per Micturition was significantly increased compared to controls. The diabetic rats, in contrast to the two control groups, had a significant increase in the number of Micturitions during the light and dark cycles. Similar to the sucrose drinking rats, the volumes excreted per Micturition were significantly greater than the normal controls. The data are discussed with regard to the effects of prolonged diuresis on bladder function and hypertrophy.
Alan J. Wein - One of the best experts on this subject based on the ideXlab platform.
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tolterodine once daily superior efficacy and tolerability in the treatment of the overactive bladder
Urology, 2001Co-Authors: Philip Van Kerrebroeck, Karl J Kreder, U Jonas, Norm Zinner, Alan J. WeinAbstract:OBJECTIVES: To evaluate the efficacy and tolerability of a new extended-release (ER), once-daily, capsule formulation of tolterodine, relative to placebo and the existing immediate-release (IR), twice-daily, tablet formulation, for treatment of the overactive bladder. METHODS: This was a double-blind, multicenter, randomized, placebo-controlled trial. One thousand five hundred twenty-nine patients (81% women) with urinary frequency (eight or more Micturitions every 24 hours) and urge incontinence (five or more episodes per week) were randomized to oral therapy with tolterodine ER 4 mg once daily (n = 507), tolterodine IR 2 mg twice daily (n = 514), or placebo (n = 508) for 12 weeks. Efficacy was assessed at the end of the treatment period on the basis of the Micturition diary variables. Tolerability and safety were assessed by evaluating the adverse events, electrocardiogram parameters, laboratory values, and treatment withdrawals. RESULTS: Tolterodine ER 4 mg once daily (P = 0.0001) and tolterodine IR 2 mg twice daily (P = 0.0005) both significantly reduced the mean number of urge incontinence episodes per week compared with placebo. The median reduction in these episodes as a percentage of the baseline values was 71% for tolterodine ER, 60% for tolterodine IR, and 33% for placebo. The ER formulation was 18% more effective than the IR formulation (P <0.05). Treatment with both formulations of tolterodine was also associated with statistically significant improvements in all other Micturition diary variables compared with placebo. For both formulations, the mean decreases in Micturition frequency (P <0.0079) and pad usage (P <0.0145) were significant, and the mean volume voided per Micturition increased (P = 0.0001). The rate of dry mouth (of any severity) was 23% for tolterodine ER, 30% for tolterodine IR, and 8% for placebo. The overall dry mouth rate for patients taking tolterodine ER was 23% lower than for tolterodine IR (P <0.02), and the rate of severe dry mouth in the ER group was only 1.8%. The rates of withdrawal were comparable for the two active groups and the placebo group. No safety concerns were noted. CONCLUSIONS: Tolterodine ER 4 mg once daily is effective and well tolerated in the treatment of overactive bladder with no safety concerns. Tolterodine ER demonstrated an improved efficacy for reducing urge incontinence episodes and a lower frequency of dry mouth compared with the existing IR twice-daily formulation.
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effects of sensitization on female guinea pig urinary bladder function in vivo and in vitro studies
The Journal of Urology, 1991Co-Authors: Alan J. Wein, Penelope A. Longhurst, Robert M. LevinAbstract:Abstract Although bladder inflammation is known clinically to produce a variety of symptoms including urgency, frequency, and pain, there are only a few experimental studies that directly relate bladder inflammation with urodynamic and functional alterations. We have used the sensitized guinea pig model to study the effects of inflammation on Micturition parameters, cystometry, and in vitro bladder contractility. This model depends on the allergic response of the bladder mucosa to ovalbumin, an otherwise non-irritative agent, as an antigen. In vivo exposure of the bladder to ovalbumin via urethral catheterization induced a prompt and marked increase in the number of Micturitions in antigen-sensitized guinea pigs. Ovalbumin had no effects on the Micturition parameters in the control group. Using in vivo cystometry, intravesical exposure to ovalbumin induced a significant decrease in both the pressure at which Micturition was induced, and the volume at which Micturition was induced. Ovalbumin had no effect on cystometric parameters of the control animals. In vitro exposure of whole-bladder preparations to ovalbumin induced a significant contractile response only in the bladders isolated from the sensitized guinea pigs. The responses of the isolated bladders to field stimulation and bethanechol were identical for bladders from both sensitized and control animals. In conclusion, exposure of the bladder to ovalbumin in the sensitized animal induced an increase in the frequency of Micturitions and a decrease in the pressure and volume at which Micturition was induced. Thus, intravesical exposure of the bladder mucosa to a substance that the bladder has been sensitized to can induce alterations in Micturition that are consistent with the clinical symptoms of “urgency and frequency”.
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comparison of urinary bladder function in sexually mature and immature male and female rats
The Journal of Urology, 1990Co-Authors: Alexa L. Chun, Alan J. Wein, Richard C Harkaway, Robert M. LevinAbstract:Abstract Although studies exist using both male and female rats, there are virtually no studies that compare male and female bladder function. In this initial study, in-vivo and in-vitro urinary bladder function was investigated in two age groups of male and female rats (sexually immature and sexually mature). These studies compare in-vivo Micturition behavior (water intake, urine output, frequency and volume per Micturition); and in-vitro whole bladder function (bladder volume/pressure relationships, the ability of the in-vitro bladders to generate pressure and empty in response to bethanechol and field stimulation). The results can be summarized as follows: 1) The 24 hour water intake, urine output, and volume per Micturition for the mature male rats was significantly greater than that of the mature females with no significant differences among the immature females, mature females, or immature males. 2) There were no significant differences in the frequency of Micturition between the 4 groups. 3) Although the average plateau pressures (cystometrograms) of the immature and mature female bladders were greater than that of the immature and mature male bladders, the compliance was similar for all groups. 4) The maximum pressure response of the mature female bladder was significantly greater than pressures generated by bladders in the other three groups; there were no age or sex related differences in the bethanechol log ED50 values. 5) There were no age or sex-related differences in the bethanechol log ED50 values or maximal expulsion responses. 6) Field stimulated bladders from mature animals generated significantly greater intravesical pressures than bladders from immature animals, but, there were no significant differences in maximal pressures attained between mature male and female bladders nor between immature male and female bladders. In conclusion, Micturition behavior, and the maximal pressure response to bethanechol changed dramatically with sexual maturity. These results are consistent with the idea that estrogen and other hormones may have a marked influence on bladder function and Micturition behavior. (J. Urol, 143: 1267–1271, 1990)
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in vivo urinary bladder function in rats following prolonged diabetic and non diabetic diuresis
Neurourology and Urodynamics, 1990Co-Authors: Penelope A. Longhurst, Alan J. Wein, Robert M. LevinAbstract:Changes in urinary bladder function are present in animal models of diabetes mellitus. In vivo cystometry in diabetic rats shows a bladder with increased capacity and a raised threshold for initiation of the Micturition reflex. At sacrifice, diabetic rats have bladder hypertrophy, resulting in approximately a doubling of the bladder weight. This study was designed to characterize the effects of diabetes on Micturition in the streptozotocin-diabetic rat. For comparative purposes, two different control groups were examined: 1) age-matched control rats and 2) age-matched rats which were given 5% sucrose to drink. Sucrose-fed rats consumed large volumes of fluid resulting in diuresis and bladder hypertrophy. Fluid consumption and excretion were significantly increased in diabetic and sucrose-drinking rats. In addition, the diabetic rats both drank and excreted more than the sucrose-drinking rats. Control rats had twice as many Micturitions during the dark cycle than during the light cycle, but the volume Micturition during the dark cycle was less than one-half the volume per Micturition during the light cycle. Sucrose drinking rats had the same number of Micturitions as control rats during the light cycle. but the volumes per Micturition were significantly increased. During the dark cycle, the number of Micturitions increased four-fold and the volume per Micturition was significantly increased compared to controls. The diabetic rats, in contrast to the two control groups, had a significant increase in the number of Micturitions during the light and dark cycles. Similar to the sucrose drinking rats, the volumes excreted per Micturition were significantly greater than the normal controls. The data are discussed with regard to the effects of prolonged diuresis on bladder function and hypertrophy.
Penelope A. Longhurst - One of the best experts on this subject based on the ideXlab platform.
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comparison of urinary bladder function in 6 and 24 month male and female rats
The Journal of Urology, 1992Co-Authors: Penelope A. Longhurst, Berit Eika, Robert E. Leggett, Robert M. LevinAbstract:Abstract Micturition characteristics, collagen composition, and in vitro urinary bladder strip contractility were examined in young adult (six month) and old (24 month) male and female Fischer 344 rats. Although young female rats consumed significantly less water than young males, there were no differences in volumes of urine excreted. Old females excreted significantly more urine than old males, but there were no differences in volumes of water consumed. Old male rats had similar Micturition frequencies during the light and dark cycles, in contrast to females and young males, where the number of Micturitions during the dark cycle was significantly greater than those during the light cycle. The mean and maximal Micturition volumes were significantly greater in old males compared to young males and old females during both the light and dark cycles. Bladders from female rats weighed significantly less than bladders from males of the same age, and the bladders from young rats weighed less than those of old rats. The protein and collagen concentrations were significantly less in bladder bodies from young females than old females. The amount of collagen resistant to digestion by Pronase, and thus thought to be cross-linked, was significantly greater in bladders from old rats compared to young. No differences between groups were found in the contractile responses of bladder base strips. There were trends for the absolute contractile responses of bladder body strips from old males to field stimulation, carbachol, ATP, and KCl to be larger than the other groups, and for strips from the young females to be smaller. The responses of strips from young females to field stimulation and KCl were significantly less than those of young males or old females, and responses to 10~3 M ATP were less than those of old females. Responses of strips from old males to 60 mM KC1 were significantly greater than those of young males. The differences in contractility could be attributed to the differences in strip mass. It appears, therefore, that urinary bladder function in male and female rats is unaffected by increasing age between 6 and 24 months.
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the influence of ovariectomy and estradiol replacement on urinary bladder function in rats
The Journal of Urology, 1992Co-Authors: Penelope A. Longhurst, Jane Kauer, Robert E. Leggett, Robert M. LevinAbstract:Abstract Female Fischer 344 rats were ovariectomized or sham operated and treated with oil or estradiol cypionate (100 mg./100 gm./month) for two or four months. Rats were then placed in metabolism cages for measurement of Micturition characteristics, and bladders were removed for bladder strip studies. Ovariectomy had no effects on Micturition characteristics. However, estradiol treatment of ovariectomized rats caused significant increases in water consumption and urine excretion, and in mean and maximal Micturition volumes compared to both ovariectomized and sham-operated rats. These effects were more pronounced at four months. Estradiol treatment also caused significant increases in bladder body mass, while ovariectomy was without effect. Two months after ovariectomy and/or estradiol treatment, there were no differences in contractile responses of bladder body or base strips to contractile agents when compared to shams. However, after four months, ovariectomy caused significant decreases in contractile responsiveness to nerve stimulation, ATP, carbachol, and KCl compared to sham-operated rats. Estradiol treatment caused increased responsiveness to nerve stimulation, ATP, carbachol, and KCl compared to ovariectomized rats, and to carbachol compared to sham operated rats. Possible causes for the effects of ovariectomy on bladder contractility include decreases in calcium influx. Although estradiol reversed the effects of ovariectomy on bladder function, in addition we observed some indirect effects which were probably the result of estradiol-induced polyuria and increases in bladder mass.
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effects of sensitization on female guinea pig urinary bladder function in vivo and in vitro studies
The Journal of Urology, 1991Co-Authors: Alan J. Wein, Penelope A. Longhurst, Robert M. LevinAbstract:Abstract Although bladder inflammation is known clinically to produce a variety of symptoms including urgency, frequency, and pain, there are only a few experimental studies that directly relate bladder inflammation with urodynamic and functional alterations. We have used the sensitized guinea pig model to study the effects of inflammation on Micturition parameters, cystometry, and in vitro bladder contractility. This model depends on the allergic response of the bladder mucosa to ovalbumin, an otherwise non-irritative agent, as an antigen. In vivo exposure of the bladder to ovalbumin via urethral catheterization induced a prompt and marked increase in the number of Micturitions in antigen-sensitized guinea pigs. Ovalbumin had no effects on the Micturition parameters in the control group. Using in vivo cystometry, intravesical exposure to ovalbumin induced a significant decrease in both the pressure at which Micturition was induced, and the volume at which Micturition was induced. Ovalbumin had no effect on cystometric parameters of the control animals. In vitro exposure of whole-bladder preparations to ovalbumin induced a significant contractile response only in the bladders isolated from the sensitized guinea pigs. The responses of the isolated bladders to field stimulation and bethanechol were identical for bladders from both sensitized and control animals. In conclusion, exposure of the bladder to ovalbumin in the sensitized animal induced an increase in the frequency of Micturitions and a decrease in the pressure and volume at which Micturition was induced. Thus, intravesical exposure of the bladder mucosa to a substance that the bladder has been sensitized to can induce alterations in Micturition that are consistent with the clinical symptoms of “urgency and frequency”.
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in vivo urinary bladder function in rats following prolonged diabetic and non diabetic diuresis
Neurourology and Urodynamics, 1990Co-Authors: Penelope A. Longhurst, Alan J. Wein, Robert M. LevinAbstract:Changes in urinary bladder function are present in animal models of diabetes mellitus. In vivo cystometry in diabetic rats shows a bladder with increased capacity and a raised threshold for initiation of the Micturition reflex. At sacrifice, diabetic rats have bladder hypertrophy, resulting in approximately a doubling of the bladder weight. This study was designed to characterize the effects of diabetes on Micturition in the streptozotocin-diabetic rat. For comparative purposes, two different control groups were examined: 1) age-matched control rats and 2) age-matched rats which were given 5% sucrose to drink. Sucrose-fed rats consumed large volumes of fluid resulting in diuresis and bladder hypertrophy. Fluid consumption and excretion were significantly increased in diabetic and sucrose-drinking rats. In addition, the diabetic rats both drank and excreted more than the sucrose-drinking rats. Control rats had twice as many Micturitions during the dark cycle than during the light cycle, but the volume Micturition during the dark cycle was less than one-half the volume per Micturition during the light cycle. Sucrose drinking rats had the same number of Micturitions as control rats during the light cycle. but the volumes per Micturition were significantly increased. During the dark cycle, the number of Micturitions increased four-fold and the volume per Micturition was significantly increased compared to controls. The diabetic rats, in contrast to the two control groups, had a significant increase in the number of Micturitions during the light and dark cycles. Similar to the sucrose drinking rats, the volumes excreted per Micturition were significantly greater than the normal controls. The data are discussed with regard to the effects of prolonged diuresis on bladder function and hypertrophy.
Ge Holstege - One of the best experts on this subject based on the ideXlab platform.
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the emotional motor system and Micturition control
Neurourology and Urodynamics, 2010Co-Authors: Ge HolstegeAbstract:Micturition is, similar to all other movements of the body, the result of activation of the motor system in the central nervous system. This review explains how the brain and brainstem control Micturition. The basic reflex system begins with a distinct cell group called Gert's Nucleus (GN) in the sacral cord. GN receives information about bladder contents via A-delta fibers from the bladder and bladder sphincter and relays this information to the central part of the midbrain periaqueductal gray (PAG), but not to the thalamus. The PAG, in turn, in case of substantial bladder filling, excites the pontine Micturition center (PMC), which cell group, via its long descending pathways to the sacral cord, induces Micturition. Higher brain regions in prefrontal cortex and limbic system, by means of its projections to the PAG are able to interrupt this basic reflex system. It allows the individual to postpone Micturition until time and place are appropriate. Lesions in the pathways from prefrontal cortex and limbic system to the PAG probably cause urge-incontinence in the elderly.
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Micturition and the soul
The Journal of Comparative Neurology, 2005Co-Authors: Ge HolstegeAbstract:There is a close connection between Micturition and emotion. Several species use Micturition to signal important messages as territorial demarcation and sexual attraction. For this reason, Micturition is coordinated not in the spinal cord but in the brainstem, where it is closely connected with the limbic system. In cat, bladder afferents terminate in a cell group in the lateral dorsal horn and lateral part of the intermediate zone. Neurons in this cell group project to supraspinal levels, not to the thalamus but to the central periaqueductal gray (PAG). Neurons in the lateral PAG, not receiving direct sacral cord afferents, project to the pontine Micturition center (PMC). The PMC projects directly to the parasympathetic bladder motoneurons and to sacral GABA-ergic and glycinergic premotor interneurons that inhibit motoneurons in Onuf's nucleus innervating the external striated bladder sphincter. Thus, PMC stimulation causes bladder contraction and bladder sphincter relaxation, i.e., complete Micturition. Other than the PAG, only the preoptic area and a cell group in the caudal hypothalamus project directly to the PMC. The ventromedial upper medullary tegmentum also sends projections to the PMC, but they are diffuse and also involve structures that adjoin the PMC. Neuroimaging studies in humans suggest that the systems controlling Micturition in cat and human are very similar. It seems that the many structures in the brain that are known to influence Micturition use the PAG as relay to the PMC. This basic organization has to be kept in mind in the fight against overactive bladder (OAB) and urge-incontinence.
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brain activation during Micturition in women
Brain, 1998Co-Authors: Ertil F M Lok, Leontie M Sturms, Ge HolstegeAbstract:Experiments in the cat have led to a concept of how the CNS controls Micturition. In a previous study this concept was tested in a PET study in male volunteers. It was demonstrated that specific brainstem and forebrain areas are activated during Micturition. It was unfortunate that this study did not involve women, because such results are important for understanding urge incontinence, which occurs more frequently in women than in men. Therefore, a similar study was done in 18 right-handed women, who were scanned during the following four conditions: (i) 15 min prior to Micturition (urine withholding); (ii) during Micturition; (iii) 15 min after Micturition; and (iv) 30 min after Micturition. Of the 18 volunteers, 10 were able to micturate during scanning and eight were not, despite trying vigorously. Micturition appeared to be associated with significantly increased blood flow in the right dorsal pontine tegmentum and the right inferior frontal gyrus. Decreased blood flow was found in the right anterior cingulate gyrus during urine withholding. The eight volunteers who were not able to micturate during scanning did not show significantly increased regional cerebral blood flow in the right dorsal, but did so in the right ventral pontine tegmentum. In the cat this region controls the motor neurons of the pelvic floor. In the same unsuccessful Micturition group, increased blood flow was also found in the right inferior frontal gyrus. In all 18 volunteers, decreased blood flow in the right anterior cingulate gyrus was found during the period when they had to withhold their urine prior to the Micturition condition. The results suggest that in women and in men the same specific nuclei exist in the pontine tegmentum responsible for the control of Micturition. The results also indicate that the cortical and pontine Micturition sites are more active on the right than on the left side.
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the central nervous system control of Micturition in cats and humans
Behavioural Brain Research, 1998Co-Authors: Ertil F M Lok, Ge HolstegeAbstract:Abstract Recent findings concerning the central control of Micturition in cats are compared to findings obtained from dynamic imaging studies in humans. In the cat, three areas in the brainstem and diencephalon are specifically implicated in the control of Micturition: (1) Barrington’s nucleus or the pontine Micturition center in the dorsomedial pontine tegmentum directly excites bladder motoneurons and indirectly inhibits, via inhibitory interneurons in the medial sacral cord, urethral sphincter motoneurons; (2) the periaqueductal grey receiving bladder filling information; and (3) the pre-optic area of the hypothalamus possibly involved in determining the beginning of Micturition. According to PET-scan studies, in humans the same supraspinal regions are active during Micturition. In the cat another area, located in the ventrolateral pontine tegmentum and is called the L-region, which controls the motoneurons of the pelvic floor, including the external urethral sphincter. This region might be considered as the pontine storage center. In humans the L-region is especially active in volunteers who tried but did not succeed to micturate. The results suggest that in cats and humans at the brainstem and diencephalic levels Micturition is organized in the same way.
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a pet study on brain control of Micturition in humans
Brain, 1997Co-Authors: Ertil F M Lok, Antoo T M Willemse, Ge HolstegeAbstract:Although the brain plays a crucial role in the control of Micturition, little is known about the structures involved. Identification of these areas is important, because their dysfunction is though to cause urge incontinence, a major problem in the elderly. In the cat, three areas in the brainstem and diencephalon are specifically implicated in the control of Micturition: the dorsomedial pontine tegmentum, the periaqueductal grey, and the preoptic area of the hypothalamus. PET scans were used to test whether these areas are also involved in human Micturition. Seventeen right-handed male volunteers were scanned during the following four conditions: (i) 15 min prior to Micturition during urine withholding: (ii) during Micturition; (iii) 15 min after Micturition; (iv) 30 min after Micturition. Ten of the 17 volunteers were able to micturate during scanning. micuturition was associated with increased blood flow in the right dorsomedial pontine tegmentum, the periaqueductal grey, the hypothalamus and the right inferior frontal gyrus. Decreased blood flow was found in the right anterior cingulate gyrus when urine was withheld. The other seven volunteers were not able to micturate during scanning, although they had a full bladder and tried vigorously to do so. In this group, during these unsuccessful attempts to micturate, increased blood flow was found in the right ventral pontine tegmentum, which corresponds with the hypothesis, formulated from results in cats, that this area controls the motor neurons of the pelvic floor. Increased blood flow was also found in the right inferior frontal gyrus during unsuccessful attempts at Micturition, and decreased blood flow in the right anterior cingulate gyrus was found during the withholding of urine. The results suggest that, as that of the cat, the human brainstem contains specific nuclei responsible for the control of Micturition, and that the cortical and pontine Micturition sites are predominantly on the right side.
Jicheng Wang - One of the best experts on this subject based on the ideXlab platform.
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pudendal but not tibial nerve stimulation inhibits bladder contractions induced by stimulation of pontine Micturition center in cats
American Journal of Physiology-regulatory Integrative and Comparative Physiology, 2016Co-Authors: Timothy D Lyo, Matthew C Ferroni, Ia T Kadow, Richard C Slate, Zhaocu Zhang, Victo Chang, Vladimi Lamm, Ing She, Jicheng WangAbstract:This study examined the possibility that pudendal nerve stimulation (PNS) or tibial nerve stimulation (TNS) inhibits the excitatory pathway from the pontine Micturition center (PMC) to the urinary ...
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brain switch for reflex Micturition control detected by fmri in rats
Journal of Neurophysiology, 2009Co-Authors: Changfeng Tai, James R Roppolo, Jicheng Wang, Ping Wang, Seonggi Kim, William C De GroaAbstract:The functions of the lower urinary tract are controlled by complex pathways in the brain that act like switching circuits to voluntarily or reflexly shift the activity of various pelvic organs (bladder, urethra, urethral sphincter, and pelvic floor muscles) from urine storage to Micturition. In this study, functional magnetic resonance imaging (fMRI) was used to visualize the brain switching circuits controlling reflex Micturition in anesthetized rats. The fMRI images confirmed the hypothesis based on previous neuroanatomical and neurophysiological studies that the brain stem switch for reflex Micturition control involves both the periaqueductal gray (PAG) and the pontine Micturition center (PMC). During storage, the PAG was activated by afferent input from the urinary bladder while the PMC was inactive. When bladder volume increased to the Micturition threshold, the switch from storage to Micturition was associated with PMC activation and enhanced PAG activity. A complex brain network that may regulate the brain stem Micturition switch and control storage and voiding was also identified. Storage was accompanied by activation of the motor cortex, somatosensory cortex, cingulate cortex, retrosplenial cortex, thalamus, putamen, insula, and septal nucleus. On the other hand, Micturition was associated with: 1) increased activity of the motor cortex, thalamus, and putamen; 2) a shift in the locus of activity in the cingulate and insula; and 3) the emergence of activity in the hypothalamus, substantia nigra, globus pallidus, hippocampus, and inferior colliculus. Understanding brain control of reflex Micturition is important for elucidating the mechanisms underlying neurogenic bladder dysfunctions including frequency, urgency, and incontinence.