Modulation of bodily response to chill stimuli by impaired structural connectivity of the left insula- a functional and lesion quantification study in stroke patients

BACKGROUND

The insula has important function in monitoring and integrating physiological responses to a personal experience of multimodal input. The experience of chills in response to auditory stimuli is an important example for a relevant arousing experience coupled with bodily response. A group study about altered chill experiences in patients with insula lesions is lacking.

METHODS

We investigated 28 stroke patients with predominantly insula lesions in the chronic stage and 14 age matched controls using chill stimuli of both valences (music, harsh sounds). We analyzed group differences in subjective chill reports, associated bodily responses (skin conductance response, SCR), lesion mapping, diffusion weighted imaging and functional magnetic resonance imaging (fMRI). Other neuropsychological deficits were excluded by comprehensive testing. Diffusion weighted imaging was quantified for four insula tracts using fractional anisotropy.

RESULTS

Frequency of chill experiences was comparable between participant groups. However, bodily responses were decreased for the stroke group. Whereas there was no association of lesion location we found a positive association for the SCR during aversive sounds and the tract connecting anterior inferior insula and left temporal pole in the stroke group. Similarly, fMRI-activation in areas hypothesized to compensate for damage was increased with bodily response.

CONCLUSIONS

We observed a decoupling of felt arousal and bodily response after insula lesion. Impaired bodily response was related to an impaired interaction of the left anterior insula and the temporal pole.

Foramen magnum compression in Coffin-Lowry syndrome: A case report

Coffin-Lowry syndrome (CLS) is a rare genetic disorder inherited in an X-linked dominant pattern. Common manifestations include intellectual disability, growth retardation, dysmorphic facial features, and variable skeletal anomalies. Here we report a patient who first presented with episodes of apparent life-threatening events (ALTE) found to be caused by hydrocephalus and brainstem compression at the foramen magnum. Together with his small size, short limbs and fingers, and facial appearance, the narrowing of the foramen magnum lead to the initial clinical misdiagnosis of hypochondroplasia. Subsequent evaluation and testing lead to the correct diagnosis of CLS. This case demonstrates the variability in presentation of CLS, and that skeletal findings may be misleading in infancy. © 2017 Wiley Periodicals, Inc.

The functional -1019C/G HTR1A polymorphism and mechanisms of fear

Serotonin receptor 1A gene (HTR1A) knockout mice show pronounced defensive behaviour and increased fear conditioning to ambiguous conditioned stimuli. Such behaviour is a hallmark of pathological human anxiety, as observed in panic disorder with agoraphobia (PD/AG). Thus, variations in HTR1A might contribute to neurophysiological differences within subgroups of PD/AG patients. Here, we tested this hypothesis by combining genetic with behavioural techniques and neuroimaging. In a clinical multicentre trial, patients with PD/AG received 12 sessions of manualized cognitive-behavioural therapy (CBT) and were genotyped for HTR1A rs6295. In four subsamples of this multicentre trial, exposure behaviour (n=185), defensive reactivity measured using a behavioural avoidance test (BAT; before CBT: n=245; after CBT: n=171) and functional magnetic resonance imaging (fMRI) data during fear conditioning were acquired before and after CBT (n=39). HTR1A risk genotype (GG) carriers more often escaped during the BAT before treatment. Exploratory fMRI results suggest increased activation of the amygdala in response to threat as well as safety cues before and after treatment in GG carriers. Furthermore, GG carriers demonstrated reduced effects of CBT on differential conditioning in regions including the bilateral insulae and the anterior cingulate cortex. Finally, risk genotype carriers demonstrated reduced self-initiated exposure behaviour to aversive situations. This study demonstrates the effect of HTR1A variation on defensive behaviour, amygdala activity, CBT-induced neural plasticity and normalization of defence behaviour in PD/AG. Our results, therefore, translate evidence from animal studies to humans and suggest a central role for HTR1A in differentiating subgroups of patients with anxiety disorders.

Dissociation and emotion regulation in borderline personality disorder

BACKGROUND

Although some evidence suggests that borderline personality disorder (BPD) is primarily a disorder of the emotion regulation system, findings remain inconsistent. One potential explanation for this is the moderating role of dissociation.

METHOD

In this study, 33 female subjects with BPD and 26 healthy controls (HC; matched by education level and nicotine intake) were presented idiographic aversive, standard unpleasant and neutral scripts. Modulation of startle reflex and electrodermal responses (skin conductance level; SCL) were measured during imagery of emotional and neutral scripts. Additionally, self-reports of emotional experience (valence and arousal) and present-state dissociation were assessed.

RESULTS

Patients with BPD showed elevated levels of dissociative experiences during testing. Present-state dissociation mediated group differences in SCL and startle response between the HC and BPD groups.

CONCLUSIONS

These results suggest that careful attention must be paid to the moderating effect of dissociative symptoms on the psychophysiological responses of BPD patients. Furthermore, the findings have important implications for the assessment and treatment of BPD, including the need to carefully assess BPD patients for dissociative symptoms and to incorporate the treatment of dissociation.

Short-term prospective comparison of prepulse inhibition between schizophrenic patients and healthy controls

INTRODUCTION

The prepulse inhibition (PPI) of acoustic startle reflex is impaired in schizophrenic individuals compared to normal controls, and has been suggested to be a biomarker for sensorimotor gating. In fact, some cross-sectional studies suggest a different type of effect on PPI changes depending on the kind of antipsychotic treatment but few prospective studies have been conducted to investigate the short-term course of PPI alterations during the first few weeks of treatment. This study aimed to investigate schizophrenic subjects and controls over 4 weeks to analyze the course of PPI changes between groups at baseline and during follow-up, to determine whether potential PPI alterations are influenced by type of antipsychotic medication and whether these alterations are accompanied by changes in psychopathology.

METHODS

39 schizophrenic patients and 39 controls were enrolled into this open prospective trial. Acoustic startle response (PPI) measurements and clinical (PANSS) performance were obtained shortly after admission and every 14 days for a 4-week follow-up period (T1 to T3).

RESULTS

Patients were treated with first and/or second generation antipsychotics in an open-label design. At baseline (T1) significant deficits were detected between schizophrenic subjects and controls for several PPI conditions. Neither was a relationship between type of antipsychotic treatment and PPI measures detected at baseline and during follow-up, nor was any association with PANSS psychopathology found.

DISCUSSION

The results of our study confirm previous research on PPI deficits in schizophrenic subjects. As with previous prospective PPI studies in schizophrenic subjects, initial PPI deficits were not observed during the follow-up period, independent of the kind of antipsychotic treatment and severity of psychopathology. These findings may indicate that PPI serves as a biological marker of schizophrenic psychosis and sensorimotor gating independent of type of antipsychotic administered or severity of psychotic symptoms.

Environmental enrichment improves functional and neuropathological indices following stroke in young and aged rats

PURPOSE

Aging is associated with a temporally dysregulated cellular response to ischemia as well as poor functional recovery. While environmental enrichment has been shown to improve the behavioral outcome of stroke in young animals, the effect of an enriched environment on behavioral and neuropathological recovery in aged animals is not known.

METHODS

Focal cerebral ischemia was produced by electrocoagulation of the right middle cerebral artery in 3 month- and 20 month-old male Sprague-Dawley rats. The functional outcome was assessed in neurobehavioral tests conducted over a period of 28 days following surgery. Brain tissue was then immunostained for proliferating astrocytes and the infarct and scar tissue volumes were measured.

RESULTS

Aged rats showed more severe behavioral impairments and diminished functional recovery compared to young rats. Most infarcted animals had disturbances of sensorimotor function, with recovery beginning later, progressing more slowly, and reaching a lower functional endpoint in aged animals. However, the enriched environment significantly improved the rate and extent of recovery in aged animals. Correlation analysis revealed that the beneficial effect of the enriched environment on recovery, both in young and aged rats, correlated highly with a reduction in infarct size, in the number of proliferating astrocytes, and in the volume of the glial scar.

CONCLUSIONS

These results suggest that temporally modulating astrocytic proliferation and the ensuing scar formation might be a fruitful approach to improving functional recovery after stroke in aged rats.

Neurotoxicological and Statistical Analyses of a Mixture of Five Organophosphorus Pesticides Using a Ray Design

Environmental exposures generally involve chemical mixtures instead of single chemicals. Statistical models such as the fixed-ratio ray design, wherein the mixing ratio (proportions) of the chemicals is fixed across increasing mixture doses, allows for the detection and characterization of interactions among the chemicals. In this study, we tested for interaction(s) in a mixture of five organophosphorus (OP) pesticides (chlorpyrifos, diazinon, dimethoate, acephate, and malathion). The ratio of the five pesticides (full ray) reflected the relative dietary exposure estimates of the general population as projected by the US EPA Dietary Exposure Evaluation Model (DEEM). A second mixture was tested using the same dose levels of all pesticides, but excluding malathion (reduced ray). The experimental approach first required characterization of dose-response curves for the individual OPs to build a dose-additivity model. A series of behavioral measures were evaluated in adult male Long-Evans rats at the time of peak effect following a single oral dose, and then tissues were collected for measurement of cholinesterase (ChE) activity. Neurochemical (blood and brain cholinesterase [ChE] activity) and behavioral (motor activity, gait score, tail-pinch response score) endpoints were evaluated statistically for evidence of additivity. The additivity model constructed from the single chemical data was used to predict the effects of the pesticide mixture along the full ray (10-450 mg/kg) and the reduced ray (1.75-78.8 mg/kg). The experimental mixture data were also modeled and statistically compared to the additivity models. Analysis of the 5-OP mixture (the full ray) revealed significant deviation from additivity for all endpoints except tail-pinch response. Greater-than-additive responses (synergism) were observed at the lower doses of the 5-OP mixture, which contained non-effective dose levels of each of the components. The predicted effective doses (ED20, ED50) were about half that predicted by additivity, and for brain ChE and motor activity, there was a threshold shift in the dose-response curves. For the brain ChE and motor activity, there was no difference between the full (5-OP mixture) and reduced (4-OP mixture) rays, indicating that malathion did not influence the non-additivity. While the reduced ray for blood ChE showed greater deviation from additivity without malathion in the mixture, the non-additivity observed for the gait score was reversed when malathion was removed. Thus, greater-than-additive interactions were detected for both the full and reduced ray mixtures, and the role of malathion in the interactions varied depending on the endpoint. In all cases, the deviations from additivity occurred at the lower end of the dose-response curves.

Accelerated glial reactivity to stroke in aged rats correlates with reduced functional recovery

Following cerebral ischemia, perilesional astrocytes and activated microglia form a glial scar that hinders the genesis of new axons and blood vessels in the infarcted region. Since glial reactivity is chronically augmented in the normal aging brain, the authors hypothesized that postischemic gliosis would be temporally abnormal in aged rats compared to young rats. Focal cerebral ischemia was produced by reversible occlusion of the right middle cerebral artery in 3- and 20-month-old male Sprague Dawley rats. The functional outcome was assessed in neurobehavioral tests at 3, 7, 14, and 28 days after surgery. Brain tissue was immunostained for microglia, astrocytes, oligodendrocytes, and endothelial cells. Behaviorally, aged rats were more severely impaired by stroke and showed diminished functional recovery compared with young rats. Histologically, a gradual activation of both microglia and astrocytes that peaked by days 14 to 28 with the formation of a glial scar was observed in young rats, whereas aged rats showed an accelerated astrocytic and microglial reaction that peaked during the first week after stroke. Oligodendrocytes were strongly activated at early stages of infarct development in all rats, but this activation persisted in aged rats. Therefore, the development of the glial scar was abnormally accelerated in aged rats and coincided with the stagnation of recovery in these animals. These results suggest that a temporally anomalous gliotic reaction to cerebral ischemia in aged rats leads to the premature formation of scar tissue that impedes functional recovery after stroke.

The specificity of infant emotional expression for emotion perception

Attachment theory emphasizes the role of negative emotional expression in infancy for establishing proximity to and care of the caregiver. According to Lang's biphasic model of emotions protective reflexes (e.g. startle response) are primed if a defensive motivational set is activated. The aim of the study was to examine whether the perception of an infant emotional expression can prime such defensive behavior. The sample consisted of 48 university students. Startle reflex, corrugator and zygomatic EMG activity and subjective ratings of valence and arousal were assessed as a response to presentation of pictures of different emotional valence. Affective startle modulation was obtained when probes were presented during pictures of the International Affective Pictures System replicating previous findings. By contrast, negative infant emotion pictures did not prompt an augmentation of the startle response, although both the subjective ratings and the mimic EMG activity indicated a clear differentiation between negative and positive infant pictures. This pattern of findings was found only in a between-subject design, but not when the two picture sets were presented in the same session, indicating an interference of contrasting content of pictures.

Ancistroealaines A and B, two new bioactive naphthylisoquinolines, and related naphthoic acids from Ancistrocladus ealaensis

Two new 5,8'-coupled naphthylisoquinoline alkaloids, ancistroealaines A (1) and B (2), eleutherolic acid (3), and two naphthoic acids, ancistronaphthoic acid A (4) and B (5), have been isolated from Ancistrocladus ealaensis. Their structures were determined by spectroscopic, chemical, and chiroptical methods. Ancistroealaine A (1) exhibited activity against Leishmania donovani and Trypanosoma cruzi in vitro.

Bilateral thoracoscopy for sympathectomy in the treatment of hyperhidrosis

Thoracoscopic sympathectomy has been established as the least invasive technique with high success rates for treatment of palmary hyperhidrosis [1,4,5]. In our procedure both sides are treated during the same operation. A bilateral thoracoscopy was performed in 20 patients for incapacitating hyperhidrosis. Immediate complications at operation were minimal. All patients reported satisfaction with the procedure in spite of compensatory sweating. The short hospital stay has significant financial benefits and these are increased if both sides are treated at the same time. This procedure is more aggressive than the single side procedure but the morbidity is not increased.

Clinical effectiveness of dermatomal evoked cerebrally recorded somatosensory responses

Among 129 patients with spine pain and radiculopathy in both the cervical and lumbar region, there were significant differences between the upper and lower extremity DSER groups, noting the higher number of normal studies by our criteria in the upper extremities as compared to the lower extremities. This difference may be due to the intertwining of the "nerve circuitry" of the input pathways. It appears that the dermatomal somatosensory evoked response is a study of low sensitivity and of high specificity.

Cerebral hemispheric asymmetry in humans. Cortical speech zones in 100 adults and 100 infant brains

Morphological asymmetry of the frontal operculum and temporal planum becomes measurable at the 29th week of gestation. There is evidence of subsequent differential development of the planum in favor of the left, with the left planum larger than the right. While both the frontal operculum and left planum were always present, the right planum ranged in size from absent (10%)to larger than the left (about 10%). Females predominated (P less than .05) in the latter group. The findings suggest that (1) a higher percentage of persons may have right-sided cerebral representation for speech than has been assumed previously; (2) a predetermined morphological asymmetry contributes to establishing the ultimate pattern of cerebral speech representation following an early insult to a predisposed hemisphere; and (3) it is necessary to scrutinize clinical material for the differential organization of hemispheric development between sexes.