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A non-anesthetized mouse model for recording sensory urinary bladder activity.

Zvara P, Wright AJ, Roach K, Ursiny M, Shapiro B, Dagrosa LM, Nelson MT, Heppner TJ - Front Neurol (2010)

Bottom Line: Intravesical infusion of 0.5% acetic acid reduced the intermicturition interval.This was associated with a 2.1-fold increase in bladder pressure during filling and a two-fold increase at both threshold and micturition pressures.Subsequent intravesical infusion of capsazepine in 0.5% acetic acid reduced filling and threshold pressures by 21 and 31.2%, respectively, and produced corresponding decreases of 36 and 23.4% in sensory nerve activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, University of Vermont College of Medicine Burlington, VT, USA.

ABSTRACT
The goal of this study was to develop an in vivo awake mouse model for extracellular bladder sensory nerve recording. A bipolar 125-μm silver electrode was positioned under a single postganglionic bladder nerve. Efferent nerve signals were eliminated by tying off the postganglionic bladder nerve between the major pelvic ganglion and the recording electrode. Sensory nerve activity was measured in the conscious animals 48 h after surgery during continuous intravesical infusion of 0.9% saline/0.5% acetic acid followed by 0.5% acetic acid with capsazepine (10 μM) at a rate of 0.75 ml/h. Continuous infusion of 0.9% NaCl led to a gradual increase in the frequency of sensory nerve firing that peaked upon reaching threshold pressure. Non-micturition contractions were observed in some animals during filling and other animals exhibited only minimal pressure fluctuations; both types of events were associated with a rise in sensory nerve activity. Intravesical infusion of 0.5% acetic acid reduced the intermicturition interval. This was associated with a 2.1-fold increase in bladder pressure during filling and a two-fold increase at both threshold and micturition pressures. Concurrent with these changes, sensory activity increased 2.8-fold during filling and 2.4-fold at threshold pressure. Subsequent intravesical infusion of capsazepine in 0.5% acetic acid reduced filling and threshold pressures by 21 and 31.2%, respectively, and produced corresponding decreases of 36 and 23.4% in sensory nerve activity. The current study shows that multifiber sensory nerve recordings can be reproducibly obtained from conscious mice.

No MeSH data available.


Related in: MedlinePlus

Hematoxylin and eosin stain of postganglionic bladder nerves removed 48 h following implantation of the recording electrode. (A) The section of the control nerve not affected by surgery. No inflammatory cells were present. (B) The contralateral nerve that was overlying the electrode. The nerve was healthy except for two microscopic foci of eosinophilic degenerative changes (arrows). The total magnification ×400.
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Figure 6: Hematoxylin and eosin stain of postganglionic bladder nerves removed 48 h following implantation of the recording electrode. (A) The section of the control nerve not affected by surgery. No inflammatory cells were present. (B) The contralateral nerve that was overlying the electrode. The nerve was healthy except for two microscopic foci of eosinophilic degenerative changes (arrows). The total magnification ×400.

Mentions: With the exception of microscopic foci of eosinophilic degenerative changes, morphological evaluation of the segment of the postganglionic bladder nerve overlying the electrode showed a normal morphology, consistent with a viable nerve. No inflammatory cells were present (Figure 6).


A non-anesthetized mouse model for recording sensory urinary bladder activity.

Zvara P, Wright AJ, Roach K, Ursiny M, Shapiro B, Dagrosa LM, Nelson MT, Heppner TJ - Front Neurol (2010)

Hematoxylin and eosin stain of postganglionic bladder nerves removed 48 h following implantation of the recording electrode. (A) The section of the control nerve not affected by surgery. No inflammatory cells were present. (B) The contralateral nerve that was overlying the electrode. The nerve was healthy except for two microscopic foci of eosinophilic degenerative changes (arrows). The total magnification ×400.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3008862&req=5

Figure 6: Hematoxylin and eosin stain of postganglionic bladder nerves removed 48 h following implantation of the recording electrode. (A) The section of the control nerve not affected by surgery. No inflammatory cells were present. (B) The contralateral nerve that was overlying the electrode. The nerve was healthy except for two microscopic foci of eosinophilic degenerative changes (arrows). The total magnification ×400.
Mentions: With the exception of microscopic foci of eosinophilic degenerative changes, morphological evaluation of the segment of the postganglionic bladder nerve overlying the electrode showed a normal morphology, consistent with a viable nerve. No inflammatory cells were present (Figure 6).

Bottom Line: Intravesical infusion of 0.5% acetic acid reduced the intermicturition interval.This was associated with a 2.1-fold increase in bladder pressure during filling and a two-fold increase at both threshold and micturition pressures.Subsequent intravesical infusion of capsazepine in 0.5% acetic acid reduced filling and threshold pressures by 21 and 31.2%, respectively, and produced corresponding decreases of 36 and 23.4% in sensory nerve activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, University of Vermont College of Medicine Burlington, VT, USA.

ABSTRACT
The goal of this study was to develop an in vivo awake mouse model for extracellular bladder sensory nerve recording. A bipolar 125-μm silver electrode was positioned under a single postganglionic bladder nerve. Efferent nerve signals were eliminated by tying off the postganglionic bladder nerve between the major pelvic ganglion and the recording electrode. Sensory nerve activity was measured in the conscious animals 48 h after surgery during continuous intravesical infusion of 0.9% saline/0.5% acetic acid followed by 0.5% acetic acid with capsazepine (10 μM) at a rate of 0.75 ml/h. Continuous infusion of 0.9% NaCl led to a gradual increase in the frequency of sensory nerve firing that peaked upon reaching threshold pressure. Non-micturition contractions were observed in some animals during filling and other animals exhibited only minimal pressure fluctuations; both types of events were associated with a rise in sensory nerve activity. Intravesical infusion of 0.5% acetic acid reduced the intermicturition interval. This was associated with a 2.1-fold increase in bladder pressure during filling and a two-fold increase at both threshold and micturition pressures. Concurrent with these changes, sensory activity increased 2.8-fold during filling and 2.4-fold at threshold pressure. Subsequent intravesical infusion of capsazepine in 0.5% acetic acid reduced filling and threshold pressures by 21 and 31.2%, respectively, and produced corresponding decreases of 36 and 23.4% in sensory nerve activity. The current study shows that multifiber sensory nerve recordings can be reproducibly obtained from conscious mice.

No MeSH data available.


Related in: MedlinePlus