Skip to main content
Log in

The pudendal nerve-evoked response in axial muscle

  • Published:
Experimental Brain Research Aims and scope Submit manuscript

Summary

In 39 Urethane-anesthetized rats we have recorded the afferent volley in the dorsal roots and the electrical activity of the lateral longissimus muscle and its motor nerves during electrical stimulation of a cutaneous branch of the pudendal nerve. Male and female rats were used; the females were ovariectomized and either pretreated with estradiol or left without hormonal treatment. Conduction velocities in the pudendal nerve were 54 m/s for the largest Abeta fibers and averaged 10 m/s for A-delta fibers. Excitation of pudendal nerve afferents strongly potentiated the firing of axial motoneurons, at stimulus currents below threshold for A-delta fibers. Trains of three shocks to the pudendal nerve were considerably more effective than double or single shock trains. Repetition rates as low as 1/s had a long lasting excitatory effect on the lateral longissimus muscle and the magnitude of the responses increased gradually for several seconds with continued stimulation. Recordings from the axons of the epaxial motoneurons of female rats showed a strong activation of neuronal firing with an onset latency of 5.8 ms from the last shock of a three ms, three shock train; the onset in male rats, 8.4 ms, differed significantly. Peak spike activity occurred at mean latencies of 11, 22 and 102 ms in both sexes. A period of depressed firing was usually present from 34 to 50 ms. Males differed in having a larger peak in activity at 102 ms, but the overall profile of the responses was similar in males and females. No differences were seen in the overall response patterns of the estrogen-treated and untreated females. Responses of comparable magnitude were seen with ipsilateral or contralateral pudendal nerve stimulation; these were facilitated by bilateral stimulation. In electromyographic recordings, the onset of unit firings was seen at 6.4 ms latency in response to pudendal nerve stimulation. This unit activity was consistent with the firing pattern seen in the muscle nerves.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Brink EE, Morrell JI, Pfaff DW (1979) Localization of lumbar epaxial motoneurons in the rat. Brain Res 170: 23–41

    Google Scholar 

  • Brink EE, Pfaff DW (1980) Ablations of lumbar epaxial musculature: effects on lordosis behavior of female rats. Brain Behav Evol 17: 67–88

    Google Scholar 

  • Brink EE, Pfaff DW (1981) Supraspinal and segmental input to lumbar epaxial motoneurons in the rat. Brain Res 226: 43–60

    Google Scholar 

  • Burgess PR, Petit D, Warren RM (1968) Receptor types in cat hairy skin supplied by myelinated fibers. J Neurophysiol 31: 833–848

    Google Scholar 

  • Carlson H, Lindquist C (1976) Exteroceptive influences on the lumbar back muscle tone and reflexes in the cat. Acta Physiol Scand 97: 332–342

    Google Scholar 

  • Cohen MS, Pfaff DW (1984) On-line data acquisition system using an Apple (tm) computer. Brain Res Bull 13: 205–223

    Google Scholar 

  • Cohen MS, Schwartz-Giblin S, Pfaff DW (1983) Responses of epaxial muscles and motor nerves to electrical stimulation of the pudendal nerves in the rat. Soc Neurosci Abstr 9: 316.15

    Google Scholar 

  • Femano PA, Schwartz-Giblin S, Pfaff DW (1984a) Brain stem reticular influences on lumbar axial muscle activity. I. Effective sites. Am J Physiol 246 (15): R389-R395

    Google Scholar 

  • Harlan RE, Shivers BD, Kow L-M, Pfaff DW (1983) Estrogenic maintenance of lordotic responsiveness: requirement for hypothalamic action potentials. Brain Res 168: 67–78

    Google Scholar 

  • Hunt CC, McIntyre AK (1960) An analysis of fibre diameter and receptor characteristics of myelinated cutaneous afferent fibres in cat. J Physiol 153: 99–112

    Google Scholar 

  • Iggo A (1966) Cutaneous receptors with a high sensitivity to mechanical displacement. In: de Reuck VS, Knight J (eds) Touch, heat and pain, Boston, pp 237–256

  • Komisarak BT, Adler NT, Hutchison J (1972) Genital sensory field: enlargement by estrogen treatment in female rats. Science 178: 1295–1298

    Google Scholar 

  • Kow L-M, Pfaff DW (1975) Dorsal root recording relevant for mating reflexes in female rats: identification of receptive fields and effects of peripheral denervation. J Neurobiol 6 (1): 23–37

    Google Scholar 

  • Kow L-M, Montgomery MO, Pfaff DW (1979) Triggering of lordosis reflex in female rats with somatosensory stimulation: quantitative determination of stimulus parameters. J Neurophysiol 42: 195–202

    Google Scholar 

  • Kow L-M, Zemlan FP, Pfaff DW (1980) Responses of lumbosacral spinal units to mechanical stimuli related to analysis of lordosis reflex in female rats. J Neurophysiol 43 (1): 27–45

    Google Scholar 

  • Kow L-M, Pfaff DW (1982) Responses of medullary reticulospinal and other reticular neurons to somatosensory and brainstem stimulation in anesthetized or freely-moving ovariectomized rats with or without estrogen treatment. Exp Brain Res 46: 191–202

    Google Scholar 

  • Muybridge EA (1887) Animal locomotion: an electro photographic investigation of consecutive phases of animal movement. University of Pennsylvania. Philadelphia

    Google Scholar 

  • Pfaff DW, Keiner M (1973) Atlas of estradiol-concentrating cells in the central nervous system of the female rat. J Comp Neurol 151: 121–158

    Google Scholar 

  • Pfaff DW, Lewis C (1974) Film analyses of lordosis in female rats. Horm Behav 5: 317–335

    Google Scholar 

  • Sakuma Y, Pfaff DW (1980) Covergent effects of lordosis-relevant somatosensory and hypothalamic influences on central gray cells in the rat mesencephalon. Exp Neurol 70: 269–281

    Google Scholar 

  • Schwartz-Giblin S, Halpern M, Pfaff DW (1984) Segmental organization of rat lateral longissimus, a muscle involved in lordosis behavior: EMG and muscle nerve recordings. Brain Res 299: 247–257

    Google Scholar 

  • Schwartz-Giblin S, Femano PA, Pfaff DW (1984) Axial electromyogram and intervertebral length gauge responses during lordosis behavior in rats. Exp Neurol 85: 297–315

    Google Scholar 

  • Shimamura M, Living'ston RB (1963) Longitudinal conduction systems serving spinal and brain stem coordination. J Neurophysiol 26: 258–272

    Google Scholar 

  • Slijper EJ (1946) Comparative biologicanatomical investigations on the vertebral column and spinal musculature of mammals. Kon Ned Akad Wet Verh (Tweedie Sectie), 42 (5): 1–128

    Google Scholar 

  • Smith ER, Damassa DA, Davidson JM (1977) Hormone administration: peripheral and intracranial implants. In: Methods in Psychobiology. Vol. 3, Academic Press, New York, pp 259–279

    Google Scholar 

  • Suzuki J-I, Cohen B (1964) Head, eye, body and limb movements from semicircular canal nerves. Exp Neurol 10: 393–405

    Google Scholar 

  • Thor KB, Kuo DC, deGroat WC, Biais D, Backes M (1982) Alterations of HRP-labelled pudendal nerve afferent projections in the sacral spinal cord of the cat during neonatal development and after spinal cord transection: correlation with physiological plasticity of a spinal somatovesical reflex. Soc Neurosci Abstr 8: 84.8

    Google Scholar 

  • Toermies JF (1938) Reflex discharge from the spinal cord over the dorsal roots. J Neurophysiol 1: 378–390

    Google Scholar 

  • Ueyama T, Mizuno N, Nomura S, Konishi A, Itoh K, Arakawa H (1984) Central distribution of afferent and efferent components of the pudendal nerve in cat. J Comp Neurol 222: 38–46

    Google Scholar 

  • Wilson VJ, Yoshida M, Schor RH (1970) Supraspinal monosynaptic excitation and inhibition of thoracic back motoneurons. Exp Brain Res 11: 282–295

    Google Scholar 

  • Zemlan FP, Kow L-M, Pfaff DW (1983) Effects of interruption of bulbospinal pathways on lordosis, posture and locomotion. Exp Neurol 81: 177–194

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Additional information

Supported by US PHS grant HD13795

Rights and permissions

Reprints and permissions

About this article

Cite this article

Cohen, M.S., Schwartz-Giblin, S. & Pfaff, D.W. The pudendal nerve-evoked response in axial muscle. Exp Brain Res 61, 175–185 (1985). https://doi.org/10.1007/BF00235633

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00235633

Key words

Navigation