The onset of diffuse noxious inhibitory controls in postnatal rat pups: a C-Fos study

Excessive brain iron has been found in several neurodegenerative diseases. However, little information is available about mechanism of iron uptake by different types of brain cells including neurons. In this study, transferrin-bound iron (Tf-Fe) accumulation in the cultured cerebellar granule cell was investigated in vitro. After 5 days of culture, the cells were incubated with 1 microM of double-labelled transferrin (1251-Tf-59Fe) at 37 degrees C for 60 min. The cellular Tf-Fe and transferrin (Tf) uptake was analysed. The result showed (1) Tf uptake by the cells increased rapidly at the first 5 min, reaching its maximum after about 20 min of incubation; (2) Tf-Fe uptake kept increasing in a linear manner during the whole period of incubation; (3) the addition of either NH4Cl or CH3NH2, the blockers of Tf-Fe uptake via inhibiting iron release from Tf within endosomes, decreased the cellular Tf-Fe uptake but had no significant effect on Tf uptake; (4) trypsin and unlabelled Tf-Fe inhibited the uptake rate of Tf-Fe as well as Tf. The results suggested that Tf-Fe transport across the membrane of this type of neuron, much like other mammalian cells, was mediated by Tf-TfR endocytosis. Dysfunction of Tf or TfR would possibly lead to iron irregulation in the brain and consequently cause damage to neuronal functions.     

Diffuse noxious inhibitory controls reduce the expression of noxious stimulus-evoked Fos-like immunoreactivity in the superficial and deep laminae of the rat spinal cord

Behavioral and electrophysiological studies have shown that a noxious stimulus applied to one part of the body can reduce the response to a subsequent noxious stimulus elsewhere on the body. This phenomenon is referred to as diffuse noxious inhibitory controls (DNIC). In the present study we used immunocytochemical labeling for the Fos protein product of the c-fos proto-oncogene to determine the location of lumbar spinal nociresponsive neurons that are inhibited by a spatially remote noxious stimulus. Repetitive hindpaw pinch evoked pronounced Fos-like immunoreactivity in the superficial and deep laminae of the lumbar spinal cord. Placing the tail in 50 degrees C water before each hindpaw pinch significantly reduced Fos-like immunoreactivity in these regions. These data demonstrate that nociresponsive neurons in both the superficial and deep laminae of the spinal cord are sensitive to inhibition by a spatially remote noxious conditioning stimulus.     

Dissociation of antinociception and escape deficits induced by stress in mice.

Six experiments (327 Swiss-Webster mice) assessed the conditions under which stress would induce antinociception in a subsequent hot-plate test. Both footshock and tail shock produced the antinociception. This effect was apparent with as little as a single shock trial. The magnitude of the antinociception was maximal following 15 shock presentations and was largely reduced after 60 shocks. In contrast to the results of R. L. Jackson et al (see record 1980-31880-001), whether stress was escapable was not a necessary feature needed to produce the antinociception. Moreover, the magnitude of the antinociception induced by stress was not enhanced in mice that had previously been exposed to stress. Finally, morphine (10.0, 20.0, and 30.0 mg/kg, ip) produced a pronounced antinociception but did not appreciably influence escape performance in a shuttle task in which performance was disrupted by inescapable shock. It is suggested that the antinociception and shuttle-escape deficits induced by uncontrollable shock are independent of one another. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gastric inhibitory polypeptide (GIP) and GIP receptor (GIPR)

Gastric inhibitory polypeptide, originally isolated from porcine intestine, is a gastrointestinal hormone belonging to the vasoactive intestinal peptide (VIP)/glucagon/secretin family. GIP consists of 42 amino acid residues which is derived by proteolytic processing of a GIP precursor. In vivo and in vitro experiments have indicated that GIP auguments glucose-stimulated insulin secretion, suggesting that GIP plays an important role in the regulation of insulin secretion as an incretin. Thus, GIP now is generally referred to as glucose-dependent insulinotropic polypeptide. It is also suggested that GIP may be involved in the pathogenesis of non insulin-dependent diabetes mellitus (NIDDM). GIP exerts its biological actions by binding to its specific receptors, which appear to be coupled to G proteins. We have isolated a cDNA encoding a GIP receptor from a hamster insulinoma(HIT-T15) cDNA library. The hamster GIP receptor is a 462 amino acid protein having seven transmembrane segments. Expression of recombinant of hamster GIP receptors in Chinese hamster ovary (CHO) cells shows that it binds specifically to GIP with high affinity (IC50 = 9.6 nM) and is positively coupled to adenylate cyclase. RNA blot analysis reveals that a 3.8-kb GIP receptor mRNA is expressed at high levels in rat pancreatic islets as well as in HIT-T15 cells.     

Anger management style and emotional reactivity to noxious stimuli among chronic pain patients and healthy controls: The role of endogenous opioids.

Objective: Previous work suggests that elevated trait anger-out exacerbates pain responses in part through endogenous opioid dysfunction. The authors examined whether this opioid dysfunction affects not only perceived pain intensity, but also emotional responses to being hurt. Design: 79 chronic low back pain (LBP) patients and 46 healthy controls received opioid blockade (8 mg naloxone i.v.) and placebo in randomized, counterbalanced order in separate sessions. During each session, participants sequentially experienced finger pressure pain and ischemic forearm pain tasks, with emotional state assessed at baseline and postpain. Main Outcome Measures: Blockade effects indexing opioid modulation of emotional reactivity were derived by subtracting placebo from blockade condition emotional reactivity. Results: Significant Participant Type × Anger-Out interactions on blockade effects indicated that in LBP participants but not in controls, greater anger-out was associated with deficient opioid modulation of anxiety, anger, and fear reactivity to noxious stimulation. Across participant types, greater anger-in was associated with impaired opioid modulation of anxiety and fear reactivity. Anger-in opioid effects were partially due to overlap with general negative affect. Conclusions: Opioid dysfunction associated with trait anger-out may affect not only perceived pain intensity, but also pain-related suffering in individuals with chronic pain conditions. Implications for understanding the health effects of anger management styles are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral characteristics of vasopressin-deficient rats (Brattleboro strain)

A group of vasopressin-deficient rats (Brattleboro strain--DI) and a group of normal Long-Evans rats were successively evaluated on visual discrimination, olfactory discrimination, delayed alternation at short and long intertrial intervals (ITIs), approach-avoidance conflict in a straight runway, and open-field behavior. It was found that DI rats adapted more slowly than normal rats in the T-maze, in the straight runway, and they were slower to emerge into the open field. The DI rats were impaired relative to normal animals on the discrimination tasks (visual and olfactory), but they were not impaired on delayed alternation (at least for short ITIs). DI rats also showed better retention of the punishment effect in the approach-avoidance conflict test than normal animals. It is suggested that DI rats have defective reference-memory mechanisms, fairly intact working-memory processes and altered adaptability (timidity or cautiousness).     

Behavioral and physiological reactions to observed violence: Effects of prior exposure to aggressive stimuli.

80 male undergraduates first watched videotaped sequences that were arousing, but which contained different degrees of violence. Ss then observed either a 2nd videotape of a sequence of aggressive acts or no videotape. Ss who were shown the 2nd videotape were told that the aggressive acts they saw were either justified or not justified, or were given no information regarding justification. It was found that Ss who had first seen an arousing but less violent tape were subsequently more aggressive toward an antagonist if they had observed justified violence. Ss who had first watched the violent videotape showed no differences in aggression as a function of the justification of the 2nd set of aggressive acts. Analysis of blood pressure data showed that prior exposure to violence attenuated arousal in response to subsequently observed aggression. The results are discussed in terms of differential sensitivity to cues that inhibit or disinhibit aggression. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral and physiological correlates of children's reactions to others in distress.

Examined the behavioral and physiological correlates of children's reactions to others in distress and the relation of these to dispositional helpfulness. 37 3rd graders and 29 6th graders watched a film about a distressed child. Facial expressions, heart rate variability (HRV), and skin conductance (SC) were recorded during the film. An index of dispositional helpfulness was obtained from children's mothers. High HRV was predictive of children's sympathetic rather than distressed reactions. For boys, sympathetic responsiveness positively predicted dispositional helpfulness; for girls, SC was inversely related to dispositional helpfulness. It was concluded that children who are able to regulate their vicariously induced emotional responsiveness are relatively likely to experience sympathy and relatively unlikely to experience personal distress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Molecular analysis of survival motor neuron (SMN) and neuronal apoptosis inhibitory protein (NAIP) genes of spinal muscular atrophy patients and their parents

We have assayed deletions of two candidate genes for spinal muscular atrophy (SMA), the survival motor neuron (SMN) and neuronal apoptosis inhibitory protein (NAIP) genes, in 101 patients from 86 Chinese SMA families. Deletions of exons 7 and 8 of the telomeric SMN gene were detected in 100%, 78.6%, 96.6%, and 16.7%, in type I, II, III, and adult-onset SMA patients, respectively. Deletion of exon 7 only was found in eight type II and one type III patient. One type II patient did not have a deletion of either exon 7 or 8. The prevalence of deletions of exons 5 and 6 of the NAIP gene were 22.5% and 2.4% in type I and II SMA patients, respectively. We also examined four polymorphisms of SMN genes and found that there were only two, SMN-2 and CBCD541-2, in Chinese subjects. In our study, analysis of the ratio of the telomeric to centromeric portion (T/C ratio) of the SMN gene after enzyme digestion was performed to differentiate carriers, normals, and SMA patients. We found the T/C ratio of exon 7 of the SMN gene differed significantly among the three groups, and may be used for carrier analysis. An asymptomatic individual with homozygous deletion of exons 7 and 8 of the SMN gene showed no difference in microsatellite markers in the SMA-related 5q11.2-5q13.3. In conclusion, SMN deletion in clinically presumed child-onset SMA should be considered as confirmation of the diagnosis. However, adult-onset SMA, a heterogeneous disease with phenotypical similarities to child-onset SMA, may be caused by SMN or other gene(s).     

Video microscopic analysis of ionophore induced acrosome reactions of lobster (Homarus americanus) sperm

Sperm from the American lobster (Homarus americanus) are normally nonmotile. However, during fertilization, the sperm undergo a calcium-dependent acrosome reaction that propels them forward about 18 microns. The reaction occurs in two phases, eversion and ejection, which take place too quickly to permit analysis by direct observation. The purposes of this study were to examine the structural changes occurring in sperm during the normal acrosome reaction and to determine the rate of the reaction using video microscopy. The reaction was induced in vitro by ionophore A23187 and recorded using a video system attached to a Nikon Nomarski interference microscope. Videotapes were played back frame by frame (30 frames/sec), and images of reactions from 10 sperm were analyzed. The acrosome reaction, including the eversion of the acrosomal vesicle and ejection of the subacrosomal material and nucleus, can be divided into 4 steps: (1) expansion of the apical cap followed by expansion of the remainder of the acrosomal cylinder; expansion of the cylinder begins at its apical end and proceeds toward its base, (2) eversion of the apical half of the acrosomal vesicle and initial contraction of the apical cap, (3) eversion of the basal half of the acrosomal vesicle, continued contraction of the apical cap, and ejection of the subacrosomal material and nucleus, and (4) final contraction of the apical cap and ejection of the acrosomal filament. During steps 2, 3, and 4, the mean forward movement of sperm is 12.7, 3.9, and 1.1 microns, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dynorphin A(1-17) mediates midazolam antagonism of morphine antinociception in mice

Studies have shown that midazolam acts in the brain to antagonize the antinociception produced by morphine. The purpose of this study was to determine if spinal dynorphin A(1-17) (Dyn) was involved in the antagonistic effects of midazolam. A number of drugs when administered intracerebroventricularly (ICV) to mice release Dyn in the spinal cord to antagonize morphine-induced antinociception. In the present study using the mouse tail-flick test, midazolam administered ICV produced a dose related reduction of the antinociception induced by morphine given intrathecally (IT). The antagonistic action of midazolam against morphine-induced antinociception involved the release of Dyn in the spinal cord, as evidenced by the following results. 1) Administration of naloxone, nor-binaltorphimine and dynorphin antiserum, IT, eliminated the antagonistic effect of midazolam, given ICV, against morphine. Treatment with these opioid antagonists and dynorphin antiserum is known to inhibit the action of spinally released Dyn. 2) Production of desensitization to the effect of spinal Dyn by pretreating with morphine, 10 mg/kg subcutaneously 3 h before the tail-flick test, abolished the antagonistic action of midazolam given ICV. A 3-h pretreatment with midazolam, ICV, also produced desensitization to the antianalgesic action of Dyn given IT. 3) Elimination of the Dyn component of action of midazolam by administration of naloxone, nor-binaltorphimine and dynorphin antiserum, IT, uncovered slight antinociceptive activity of midazolam, given ICV. Coadministration of flumazenil (a benzodiazepine antagonist), bicuculline (a GABA antagonist) and picrotoxin (a chloride ion channel blocker) inhibited the midazolam effect.(ABSTRACT TRUNCATED AT 250 WORDS)     

Disulfide analysis reveals a role for macrophage migration inhibitory factor (MIF) as thiol-protein oxidoreductase

The mere exposure effect is the increase in positive affect that results from the repeated exposure to previously novel stimuli. We sought to determine if judgments other than affective preference could reliably produce a mere exposure effect for two-dimensional random shapes. In two experiments, we found that brighter and darker judgments did not differentiate target from distracter shapes, liking judgments led to target selection greater than chance, and disliking judgments led to distracter selection greater than chance. These results for brighter, darker, and liking judgments were obtained regardless of whether shape recognition was greater (Experiment 1) or not greater (Experiment 2) than chance. Effects of prior exposure to novel shapes were reliably observed only for affective judgment tasks. These results are inconsistent with general predictions made by the nonspecific activation hypothesis, but not the affective primacy or perceptual fluency hypotheses which were discussed in terms of cognitive neuroscience research.     

Spondylosis deformans and diffuse idiopathic skeletal hyperostosis (DISH) in Finland

A population study with 6-year follow-up of 6 167 persons aged over 30 was carried out in nine population groups in Southern Finland. Estimation of spondylosis and DISH (Diffuse Skeletal Hyperostosis) was made from lateral chest X-rays. Reliability coefficients (kappa) in the repeat reading of 1 025 films ranged between 0.60 and 0.76. 214 cases of newly developed DISH and 1 080 of spondylosis were observed. With the exception of 4 new cases, all cases of DISH had developed in persons who had had spondylosis at baseline or developed it during the follow-up. The sexual incidence of spondylosis was fairly similar, i.e. 4 cases per 100 person years in both. Prevalence and incidence of spondylosis were highest in rural areas, in persons with strenuous occupations and in the obese. Incidence of DISH was 0.7 cases per 100 person years in men and 0.4 in women. DISH was equally common in all types of population. It was not associated with arduousness of occupation. Obesity and-to a lesser degree-diabetes mellitus and glucose intolerance were associated with DISH. Neither condition was associated with elevated serum calcium, serum cholesterol or bacteriuria. The study supports the concept that DISH is epidemiologically and pathogenetically different from spondylosis deformans.     

Behavioral expectations: Development of parallel forms and analysis of scale assumptions.

Describes the development of parallel forms of behavioral expectation scales (BES) as well as a check on the adequacy of examples contributed as documentation for BES numerical evaluations. Data generated by O. Harari and S. Zedeck (see record 1974-11883-001) were used to develop 2 forms of BES, A and B. Results from 95 undergraduates indicate that the forms had, in general, equivalent dimension means and variances as well as the same degree of correlation with other variables (overall evaluation and satisfaction with the instructor). An independent sample of 56 students assessed 39 contributed examples provided to support actual evaluations. Results indicate high agreement between the original value and the independent assessments. The flexibility and increased use of the BES data are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Counselor recognition of transference reactions: Reply to Mallinckrodt (1996) and Carter (1996).

J. A. Carter (see record 199600458-003) and B. Mallinckrodt (see record 199600458-002) have provided thought-provoking critiques of the article (K. D. Multon, M. J. Patton, & D. M. Kivlighan; see record 199600458-001) that described the development of the Missouri Identifying Transference Scale. This reply attempts to address the issues of construct definition noted by both respondents, argues for the importance of a multimethod approach in describing transference, and attempts to differentiate transferential aspects of the relationship from other relational components. (PsycINFO Database Record (c) 2010 APA, all rights reserved)