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Depletion of substance P axons in substantia gelatinosa of patients with diminished pain sensitivity
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or an increase followed by a decrease. Typically the firing of single impulses was replaced by doublets or triplets. Adrenaline also fired some previously silent fibers. Although ischemia also fired off the same fibers, it was shown that the adrenergically induced activity was not due to this factor. Phentolamine blocked the effect of adrenaline but had no effect on the spontaneous discharge nor that induced by ischemia. Acetylcholine had no effect. Various experiments showed that the region of abnormal adrenergic sensitivity was in the region of the nerve end. It was concluded that the region of abnormal sensitivity to adrenaline was at sprouts of the axons or at "the zone of dysmyelination just proximal to the cut end.' Spontaneous rhythmic motor unit potentials in the carpal tunnel syndrome. - - F. Spaans, J. Neurol. Neurosurg. Psychiat., 45 (1982) 19-28. Ongoing spontaneous motor unit activity was found in the lateral thenar muscles in 18 of 164 patients with the carpal tunnel syndrome. In most cases a single motor unit was firing off in doublets or triplets. Ischemia at first increased and later greatly decreased the activity. This activity was also suppressed by strong contraction of the muscles and by supramaximal stimulation of the median nerve. By blocking the median nerve at the elbow, it was shown that the site of generation of the spontaneous motor impulses was distal to the elbow and probably at the compression site at the carpus.
PEPTIDES Review: Endogenous opiates: 1980. - - G.A. Olson, R.A. Olson, A.J. Kastin and D.H. Coy, Peptides, 2 (1981) 349-369. This useful review covers over 300 recent (1980) papers in several areas related to endogenous opioids. Topics receiving attention are: opiate receptors, opioid peptide precursors, opioids in non-mammalian vertebrates and invertebrates, the anatomical distribution of opioid peptides and receptors, new peptides (including Dynorphin) and metabolically stable analogs, behavioral and clinical aspects, hormonal interactions and clinical aspects, hormonal interactions and other related topics. Debate continues over the significance of multiple opiate receptors. New and interesting synthetic analogs have been developed. Our knowledge of the synthesis and catabolism of opioid peptides continues its rapid advance. Substance P analog, DiMe-C7: evidence for stability in rat brain and prolonged central actions. - - A.S. Eison, S.D. lversen, B.E.B. Sandberg, S.P. Watson, M.R. Hanley and L.L. Iversen, Science, 215 (1982) 188-190. The authors show that a substance P analog produces behavioral effects that are prolonged by a duration that reflects its increased metabolic stability. Depletion of substance P axons in substantia gelatinosa of patients with diminished pain sensitivity. - - J. Pearson, L. Brandeis and A.C. Cuello, Nature (Lond.), 295 (1982) 7. Patients with familial dysautonomia have reduced pain and temperature sensitiv-
216 ity, fewer dorsal root ganglion cells and small Lissauer's tracts. Immunohistochemical examination of tissues from 5 patients with this condition showed almost complete absence of substance P in the substantia gelatinosa but apparently normal amounts in the substantia nigra. Sensory and motor functions of spinal cord substance P. - - M. Piercey, L. Schroeder,
K. Folkers, J.C. Xu and J. Horig, Science, 214 ( 1981) 1361-1363. In mice, either intrathecal substance P or cutaneously applied capsaicin elicit biting and scratching behavior, presumably via release of substance P. These effects are blocked by the substance P antagonist D-Pro2-D-Phe7-D-Trpg-sP (!.0 nmole). This supports a role for substance P or a pain transmitter.
MEDICINE Changes of cutaneous sensory thresholds induced by non-painful transcutaneous electrical nerve stimulation in normal subjects and in subjects with chronic pain. - M. Zoppi, F. Francini, M. Maresca and P. Procacci, J. Neurol. Neurosurg. Psychiat.,
44 (1981) 708-717. Changes of sensory thresholds induced by non-painful transcutaneous electrical nerve stimulation (TENS) were analyzed in normal subjects and in patients with chronic myofascial pain in one lower limb. The thresholds of the tactile, tingling and painful sensations were measured by means or electrical stimuli in the distribution area of the stimulated nerve (local thresholds) and in other areas (general thresholds). There were changes in thresholds within the territory of the electrically stimulated nerve, and changes elsewhere and generally in the body. Trends of the sensory thresholds during and after TENS differed in different healthy subjects according to their thresholds before TENS. In the group of patients there was a significant difference between thresholds on the two sides of the body. The difference between the two sides was reduced by TENS. Pain relief induced by TENS may be related to this fact.
NURSING Will it hurt less if I can control it? A complex answer to a simple question, m S.C.
Thompson, Psychol. Bull., 90 (1981) 89-101. The relation between control over an aversive event and the amount of stress or pain the event produces has been of interest to researchers in health psychology. This article presents a typology of control and reviews research that relates the 4 types of control (behavioral, cognitive, information, and retrospective) to reactions to aversive stimuli. After reviewing theories relevant to this area, a unifying theme is presented. It is proposed that reactions to potentially stressful events depend on their meaning for the individual. Three dimensions of meaning are discussed:
or an increase followed by a decrease. Typically the firing of single impulses was replaced by doublets or triplets. Adrenaline also fired some previously silent fibers. Although ischemia also fired off the same fibers, it was shown that the adrenergically induced activity was not due to this factor. Phentolamine blocked the effect of adrenaline but had no effect on the spontaneous discharge nor that induced by ischemia. Acetylcholine had no effect. Various experiments showed that the region of abnormal adrenergic sensitivity was in the region of the nerve end. It was concluded that the region of abnormal sensitivity to adrenaline was at sprouts of the axons or at "the zone of dysmyelination just proximal to the cut end.' Spontaneous rhythmic motor unit potentials in the carpal tunnel syndrome. - - F. Spaans, J. Neurol. Neurosurg. Psychiat., 45 (1982) 19-28. Ongoing spontaneous motor unit activity was found in the lateral thenar muscles in 18 of 164 patients with the carpal tunnel syndrome. In most cases a single motor unit was firing off in doublets or triplets. Ischemia at first increased and later greatly decreased the activity. This activity was also suppressed by strong contraction of the muscles and by supramaximal stimulation of the median nerve. By blocking the median nerve at the elbow, it was shown that the site of generation of the spontaneous motor impulses was distal to the elbow and probably at the compression site at the carpus.
PEPTIDES Review: Endogenous opiates: 1980. - - G.A. Olson, R.A. Olson, A.J. Kastin and D.H. Coy, Peptides, 2 (1981) 349-369. This useful review covers over 300 recent (1980) papers in several areas related to endogenous opioids. Topics receiving attention are: opiate receptors, opioid peptide precursors, opioids in non-mammalian vertebrates and invertebrates, the anatomical distribution of opioid peptides and receptors, new peptides (including Dynorphin) and metabolically stable analogs, behavioral and clinical aspects, hormonal interactions and clinical aspects, hormonal interactions and other related topics. Debate continues over the significance of multiple opiate receptors. New and interesting synthetic analogs have been developed. Our knowledge of the synthesis and catabolism of opioid peptides continues its rapid advance. Substance P analog, DiMe-C7: evidence for stability in rat brain and prolonged central actions. - - A.S. Eison, S.D. lversen, B.E.B. Sandberg, S.P. Watson, M.R. Hanley and L.L. Iversen, Science, 215 (1982) 188-190. The authors show that a substance P analog produces behavioral effects that are prolonged by a duration that reflects its increased metabolic stability. Depletion of substance P axons in substantia gelatinosa of patients with diminished pain sensitivity. - - J. Pearson, L. Brandeis and A.C. Cuello, Nature (Lond.), 295 (1982) 7. Patients with familial dysautonomia have reduced pain and temperature sensitiv-
216 ity, fewer dorsal root ganglion cells and small Lissauer's tracts. Immunohistochemical examination of tissues from 5 patients with this condition showed almost complete absence of substance P in the substantia gelatinosa but apparently normal amounts in the substantia nigra. Sensory and motor functions of spinal cord substance P. - - M. Piercey, L. Schroeder,
K. Folkers, J.C. Xu and J. Horig, Science, 214 ( 1981) 1361-1363. In mice, either intrathecal substance P or cutaneously applied capsaicin elicit biting and scratching behavior, presumably via release of substance P. These effects are blocked by the substance P antagonist D-Pro2-D-Phe7-D-Trpg-sP (!.0 nmole). This supports a role for substance P or a pain transmitter.
MEDICINE Changes of cutaneous sensory thresholds induced by non-painful transcutaneous electrical nerve stimulation in normal subjects and in subjects with chronic pain. - M. Zoppi, F. Francini, M. Maresca and P. Procacci, J. Neurol. Neurosurg. Psychiat.,
44 (1981) 708-717. Changes of sensory thresholds induced by non-painful transcutaneous electrical nerve stimulation (TENS) were analyzed in normal subjects and in patients with chronic myofascial pain in one lower limb. The thresholds of the tactile, tingling and painful sensations were measured by means or electrical stimuli in the distribution area of the stimulated nerve (local thresholds) and in other areas (general thresholds). There were changes in thresholds within the territory of the electrically stimulated nerve, and changes elsewhere and generally in the body. Trends of the sensory thresholds during and after TENS differed in different healthy subjects according to their thresholds before TENS. In the group of patients there was a significant difference between thresholds on the two sides of the body. The difference between the two sides was reduced by TENS. Pain relief induced by TENS may be related to this fact.
NURSING Will it hurt less if I can control it? A complex answer to a simple question, m S.C.
Thompson, Psychol. Bull., 90 (1981) 89-101. The relation between control over an aversive event and the amount of stress or pain the event produces has been of interest to researchers in health psychology. This article presents a typology of control and reviews research that relates the 4 types of control (behavioral, cognitive, information, and retrospective) to reactions to aversive stimuli. After reviewing theories relevant to this area, a unifying theme is presented. It is proposed that reactions to potentially stressful events depend on their meaning for the individual. Three dimensions of meaning are discussed: