HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Buss, R. R. Articles by Shefchyk, S. J. Search for Related Content PubMed PubMed Citation Articles by Buss, R. R. Articles by Shefchyk, S. J.

Excitability changes in sacral afferents innervating the urethra, perineum and hindlimb skin of the cat during micturition

R. R. Buss and S. J. Shefchyk

Excitability changes in afferents innervating the urethra, perineum and hindlimb were measured in decerebrated cats during micturition and in response to stimulation of lumbosacral afferents. Increases in excitability were interpreted as primary afferent depolarization (PAD) and decreases as primary afferent hyperpolarization.

Excitability increases were observed in 11 of 19 urethral pudendal afferents during micturition. Four of these 11 afferents showed an excitability increase during voiding. Seven of these showed a biphasic change with a decrease in excitability when sphincter activity resumed at the end of the void. Three of 19 afferents showed an excitability decrease during micturition and no change was detected in five afferents.

During micturition, the peak amplitude of urethral afferent-evoked excitatory postsynaptic potentials in seven of eight sphincter motoneurones was diminished to a mean of 36 % of control values.

Eighty per cent of hindlimb cutaneous afferents and 50 % of dorsal penile/clitoral and superficial perineal nerve afferents in the sacral cord showed increased excitability during voiding. No excitability increases were measured in 13 hindlimb cutaneous fibres examined in the lumbar segments.

PAD was observed in sacral urethral, perineal and hindlimb cutaneous afferents in response to electrical stimulation of other perineal, urethral, hindlimb cutaneous and group II muscle afferents.

It is concluded that control of transmission from urethral afferents by the micturition circuitry is different to that by sensory transmission from hindlimb and perineal regions during micturition. We hypothesize that more than one population of sacral PAD-mediating interneurones is involved.

This article has been cited by other articles:

				J. W. Boggs, B. J. Wenzel, K. J. Gustafson, and W. M. Grill Frequency-dependent selection of reflexes by pudendal afferents in the cat J. Physiol., November 15, 2006; 577(1): 115 - 126. [Abstract] [Full Text] [PDF]

				J. W. Boggs, B. J. Wenzel, K. J. Gustafson, and W. M. Grill Spinal Micturition Reflex Mediated by Afferents in the Deep Perineal Nerve J Neurophysiol, May 1, 2005; 93(5): 2688 - 2697. [Abstract] [Full Text] [PDF]

				J. C. Rekling, G. D. Funk, D. A. Bayliss, X.-W. Dong, and J. L. Feldman Synaptic Control of Motoneuronal Excitability Physiol Rev, April 1, 2000; 80(2): 767 - 852. [Abstract] [Full Text] [PDF]