Elsevier

Brain Research

Volume 571, Issue 1, 31 January 1992, Pages 26-34
Brain Research

Responses of neurons in ventroposterolateral nucleus of primate thalamus to urinary bladder distension

https://doi.org/10.1016/0006-8993(92)90506-5Get rights and content

Abstract

The purpose of this study was to examine effects of a noxious visceral stimulus, urinary bladder distension (UBD), on cells in the ventroposterolateral (VPL) nucleus of anesthetized monkeys. We hypothesized that processing of visceral information in the VPL nucleus of the thalamus is similar to spinothalamic tract (STT) organization of visceral afferent input. Urinary bladder distention excites sacral and upper-lumbar STT cells that have somatic input from proximal somatic fields25; whereas, thoracic STT cells are inhibited by UBD7. Extracellular action potentials of 67 neurons were recorded in VPL nucleus. Urinary bladder distention excited 22 cells, inhibited 9 cells, and did not affect activity of 36 cells. Seventeen of 22 cells excited by UBD also received convergent somatic input from noxious squeeze of the hip, groin, or perineal regions. No cells activated only by innocuous somatic stimuli were excited by UBD. Five of 9 cells inhibited by UBD had upper-body somatic fields. There was a significant tendency for VPL neurons excited by UBD to have proximal lower-body somatic fields that were excited by noxious stimulation of skin and underlying muscle (P < 0.001). Antidromic activation of 4 thalamic neurons affected by UBD showed that visceral input stimulated by UBD reached the primary somatosensory (SI) cortex.

References (34)

  • Albe-FessardD. et al.

    Diencephalic mechanisms of pain sensation

    Brain Res. Rev.

    (1985)
  • BahnsE. et al.

    Functional characteristics of lumbar visceral afferent fibers from the urinary bladder and the urethra in the cat

    Pflügers Arch.

    (1986)
  • BahnsE. et al.

    Responses of sacral visceral afferents from the lower urinary tract, colon, and anus to mechanical stimulation

    Pfluegers Arch.

    (1987)
  • BerkleyK.J.

    Spatial relationships between the terminations of somatic sensory and motor pathways in the rostral brainstem of cats and monkeys. I. Ascending sensory inputs to lateral diencephalon

    J. Comp. Neurol.

    (1980)
  • BolserD.C. et al.

    Convergence of phrenic and cardiopulmonary spinal afferent fibers on cervical and thoracic spinothalamic tract neurons in the monkey: implications for referred pain from the diaphragm and heart

    J. Neurophysiol.

    (1991)
  • BrennanT.J. et al.

    Urinary bladder and hindlimb afferent input inhibits activity of primate T2-T5 spinothalamic tract neurons

    J. Neurophysiol.

    (1989)
  • CaseyK.L. et al.

    Ventral posterior thalamic neurons differentially responsive to noxious stimulation of the awake monkey

    Science

    (1983)
  • Cited by (0)

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