Ghrelin is related to lower brain reward activation during touch.

The gut hormone ghrelin drives food motivation and increases food intake, but it is also involved in the anticipation of and response to rewards other than food. This pre-registered study investigated how naturally varying ghrelin concentrations affect the processing of touch as a social reward in humans. Sixty-seven volunteers received slow caressing touch (so-called CT-targeted touch) as a social reward and control touch on their shins during 3T functional imaging on two test days. On one occasion, participants were fasted, and on another, they received a meal. On each occasion, plasma ghrelin was measured at three time points. All touch was rated as more pleasant after the meal, but there was no association between ghrelin concentrations and pleasantness. CT-targeted touch was rated as the most pleasant and activated somatosensory and reward networks (whole brain). A region-of-interest in the right medial orbitofrontal cortex (mOFC) showed lower activation during all touches, the higher the ghrelin concentrations were. During CT-targeted touch, a larger satiety response (ghrelin decrease after the meal) was associated with higher mOFC activation, and this mOFC activation was associated with higher experienced pleasantness. Overall, higher ghrelin concentrations appear to be related to a lower reward value for touch. Ghrelin may reduce the value of social stimuli, such as touch, to promote food search and intake in a state of low energy. This suggests that the role of ghrelin goes beyond assigning value to food reward.

Variants within the GABA transaminase (ABAT) gene region are associated with somatosensory evoked EEG potentials in families at high risk for affective disorders.

BACKGROUND: Depression frequently co-occurs with somatization, and somatic complaints have been reported as a vulnerability marker for affective disorders observable before disease onset. Somatization is thought to result from an increased attention to somatic sensations, which should be reflected in long-latency somatosensory evoked electroencephalogram (EEG) potentials (SSEPs) at the physiological level. Previous studies revealed that SSEPs are altered in depressed patients and suggested late SSEP components as vulnerability markers for affective disorders. Neurotransmitters such as serotonin, γ-aminobutyric acid (GABA) and the neuropeptide substance P may play an important role for both affective disorders and somatosensory processing. Method We investigated the associations between SSEPs and polymorphisms within candidate genes of the serotonergic, GABAergic as well as the substance P system in subjects at high risk for affective disorders. The sample was composed of high-risk families participating in the Munich Vulnerability Study and genetic association analyses were calculated using qfam (family-based association tests for quantitative traits) implemented in PLINK 1.05. RESULTS: We observed significant associations (false discovery rate <0.05) withstanding correction for multiple testing between late SSEP components (response strength 170-370 ms after stimulation) and four single nucleotide polymorphisms within the GABA transaminase (ABAT) gene region coding for a protein responsible for GABA degradation. No effects were found with the classical disease trait approach, suggesting SSEP marker specificity of the observed associations. CONCLUSIONS: Our findings point to a possible role of ABAT gene-regulated GABA catabolism for an altered processing of somatosensory stimuli as a potential vulnerability marker for affective disorders.

Interpersonal stroking touch is targeted to C tactile afferent activation.

C tactile fibers are a specialized group of fibers innervating the non-glabrous skin that are tuned to light gentle stroking applied with velocities between 1 and 10 cm/s. Those fibers add to the sensation of interpersonal caressing and pleasant touch. It is unclear whether people spontaneously apply touch that is tuned to optimally activate those fibers. This was investigated in three studies. In study one, 45 participants (21.8 ± 2.3 years, 24 women) were asked to stroke an artificial arm. In study two, 32 participants (28.3 ± 8.7 years, 16 women) were asked to stroke their partner. In study three, 11 parents (29.4 ± 5.7 years, 6 women) were asked to stroke their babies. Stroking velocity was tracked in all conditions. Stroking velocities were significantly slower in the partner touch and baby touch condition than in the artificial arm condition and all of the participants stroking their partner or baby used velocities that can activate C tactile fibers. We conclude that human social stroking is optimized for C tactile stimulation.

Refinement of map position of the human GluR6 kainate receptor gene (GRIK2) and lack of association and linkage with idiopathic generalized epilepsies.

Hereditary factors play a major role in the etiology of idiopathic generalized epilepsies (IGEs). The pivotal function of glutamate receptors (GluRs) in excitatory neurotransmission implicates their involvement in epileptogenesis and genetic susceptibility to IGEs. A trinucleotide repeat polymorphism detected in the 3' untranslated region of the kainate-selective GluR6 receptor gene (GRIK2) on chromosome 6 makes it possible to perform linkage and association studies with this high-ranking candidate gene. The present study tested the hypothesis that allelic variants of GRIK2 contribute to the genetic susceptibility to the common IGEs. Linkage and association analyses were conducted in 63 families ascertained through IGE patients with juvenile myoclonic epilepsy, juvenile absence epilepsy, or childhood absence epilepsy. Our linkage and association results suggest that allelic variants of GRIK2 are not involved in the expression of the common familial IGEs, and radiation hybrid mapping assigns GRIK2 to the chromosomal region 6q16.3-q21. This localization excludes GRIK2 as a candidate for the putative IGE susceptibility locus "EJM1" on the short arm of chromosome 6.

Impaired self-perception of the hand in complex regional pain syndrome (CRPS).

To investigate neglect, extinction, and body-perception in patients suffering from complex regional pain syndrome (CRPS). So-called 'neglect-like' symptoms have been reported in CRPS, however no studies have yet analyzed this phenomenon which might substantiate the theory of the central nervous system involvement in the pathophysiology of CRPS. A total of 114 patients with CRPS of the upper limb underwent bedside neurological examination. 'Neglect-like' symptoms were determined by asking all patients what kind of feeling they had toward the affected hand (feeling of foreignness). Hemispatial neglect was tested with the line bisection task in 29 patients and sensory extinction to simultaneous stimulation in 40 patients. The ability to identify fingers after tactile stimulation was tested in 73 patients. Independently of the affected side and disease duration, 54.4% of the patients reported that their hand felt 'foreign' or 'strange'. The ability to identify fingers was impaired in 48% on the affected hand and in 6.5% on the unaffected hand ( X(2) = 33.52, df = 1, p < 0.0001). These findings were related to pain intensity, illness duration and the extent of sensory deficits. No typical abnormalities indicating neglect were found in the line bisection test. Sensory extinction was normal in all patients. A large proportion of CRPS patients have disturbances of the self-perception of the hand, indicating an alteration of higher central nervous system processing. There are no indicators that classic neglect or extinction contribute to these findings. Physical therapy of such patients should take this observation into consideration.

Allelic association of juvenile absence epilepsy with a GluR5 kainate receptor gene (GRIK1) polymorphism.

Juvenile absence epilepsy (JAE) is a common subtype of idiopathic generalized epilepsy (IGE). Hereditary factors play a major role in its etiology. The important function of glutamate receptors (GluRs) in excitatory neurotransmission, synaptic plasticity, and neurodevelopment suggests their involvement in epileptogenesis. A tetranucleotide repeat polymorphism in the non-coding region of the kainate-selective GluR5 receptor gene (GRIK1) on chromosome 21q22.1 provides the tool to investigate this candidate gene. The present association and linkage study tested the hypothesis that allelic variants of GRIK1 confer genetic susceptibility to the pathogenesis of JAE. Our family-based association analysis using the haplotype-based haplotype relative risk statistic revealed an association of JAE with the nine-repeat containing allele of the GRIK1 tetranucleotide polymorphism (chi2 = 8.31, df = 1, P = 0.004). Supportive evidence for linkage to a JAE related IGE spectrum (Zmax = 1.67 at GRIK1) under an autosomal dominant mode of inheritance and significant allele sharing (P < 0.05) among the affected family members suggest that allelic variants of GRIK1 contribute a major genetic determinant to the pathogenesis of JAE-related phenotypes.

Evaluation of a putative major susceptibility locus for juvenile myoclonic epilepsy on chromosome 15q14.

Juvenile myoclonic epilepsy (JME) is a genetically determined common subtype of idiopathic generalized epilepsy (IGE). Significant evidence for linkage has been reported for a susceptibility locus for JME in the chromosomal region 15q14 that harbors the gene encoding the alpha7 subunit of the neuronal nicotinic acetylcholine receptor (CHRNA7). The present study was designed to test the earlier linkage finding and to explore whether this susceptibility locus is involved in the epileptogenesis of a broader spectrum of IGE syndromes. Multipoint parametric and nonparametric linkage analyses with seven microsatellite polymorphisms encompassing the region of the CHRNA7 gene were performed using two diagnostic schemes of JME-related traits in two groups of multiplex families ascertained through probands with either JME (n = 27) or idiopathic absence epilepsy (n = 30). The present linkage study failed to replicate evidence for a major susceptibility locus for JME in the region encompassing the CHRNA7 gene. In addition, we found no hint in favor of linkage to 15q14 under the broad diagnostic scheme in any of the sets of families. If genetic variation in this region confers susceptibility to JME, then its effect size might be too small or its occurrence too rare to be detected in the investigated families.

Common subtypes of idiopathic generalized epilepsies: lack of linkage to D20S19 close to candidate loci (EBN1, EEGV1) on chromosome 20.

Hereditary factors play a major role in the etiology of idiopathic generalized epilepsies (IGEs). A trait locus (EBN1) for a rare subtype of IGEs, the benign neonatal familial convulsions, and a susceptibility gene (EEGV1) for the common human low-voltage electroencephalogram have been mapped close together with D20S19 to the chromosomal region 20q13.2. Both loci are potential candidates for the susceptibility to IGE spectra with age-related onset beyond the neonatal period. The present study tested the hypothesis that a putative susceptibility locus linked to D20S19 predisposes to spectra of IGEs with age-related onset from childhood to adolescence. Linkage analyses were conducted in 60 families ascertained through IGE patients with juvenile myoclonic epilepsy, juvenile absence epilepsy or childhood absence epilepsy. Our results provide evidence against linkage of a putative susceptibility gene for four hierarchically broadened IGE spectra with D20S19 assuming tentative single-locus genetic models. The extent of an "exclusion region" (lod scores below-2) varied from 0.5 cM up to 22 cM on either side of D20S19 depending on the trait assumed. These results are contrary to the expectation that a susceptibility gene in vicinity to D20S19 confers a common major gene effect to the expression of IGE spectra with age-related onset from childhood to adolescence.

Impaired arithmetic facts but intact conceptual knowledge--a single-case study of dyscalculia.

We present the case of a young, highly educated patient who showed severe problems in basic arithmetic after a bone marrow transplant followed by extensive irradiation and chemotherapy. Despite his inability to resolve arithmetical fact problems (as 2 + 3), he showed intact processing of algebraic expressions and excellent understanding of complex arithmetic text problems. He perfectly knew arithmetic principles and applied them in various tasks. The performance of the patient suggests that conceptual knowledge (in addition to arithmetical fact knowledge and arithmetic procedures) is a functionally independent component of the calculation system.

The effects of brain lesions on the course of chronic epilepsies.

The effect of intercurrent brain lesions on the characteristics of chronic epilepsies has not yet been the subject of detailed investigation. We therefore retrospectively examined this issue for idiopathic, cryptogenic as well as symptomatic chronic epilepsies in patients documented in routine investigations at our outpatient seizure unit between the occurrence of epilepsy and commencement of the study. The clinical criteria for inclusion in this study were brain injury by trauma, stroke or intracerebral hemorrhage, documented by CT scan, and the occurrence of this so-called index event in patients with established chronic epilepsy. These requirements were met by 63 patients (40 male, mean age 44.8 years, SD 14.7 a; 23 female, mean age 43.1 years, SD 16.4 a). Seizure characteristics, EEG recordings as well as seizure frequencies before and after the index event were compared. Patients and controls were observed for a mean time of 22.12 years (SD 7.33 a) and 22.01 years (SD 11.31 a), respectively. Two patients presenting with generalized seizures prior to brain injury underwent a change in seizure characteristics. One control (without intercurrent brain lesion; matched for age, sex, age at onset of seizure disorder and classification of seizure disorder) primarily presenting with partial seizures evolving to generalized seizures showed changed seizure characteristics. These changes are statistically insignificant (McNemar test for the significance of changes). Seizure frequencies decreased significantly after brain injury. EEG recordings mirrored clinical findings with additional focal aspects according to brain lesion. These findings are discussed mainly with respect to the cofactorial etiology of epilepsies.(ABSTRACT TRUNCATED AT 250 WORDS)

Exclusion of linkage between idiopathic generalized epilepsies and the GABAA receptor alpha 1 and gamma 2 subunit gene cluster on chromosome 5.

Hereditary factors play a major role in the etiology of idiopathic generalized epilepsies (IGEs). The pivotal function of ionotropic gamma-aminobutyric acid type A receptors (GABRs) in inhibitory neurotransmission in the mammalian central nervous system suggests that they may be involved in epileptogenesis and genetic predisposition to IGEs. Dinucleotide repeat polymorphisms associated with the human GABAA receptor alpha 1 (GABRA1) and gamma 2 subunit (GABRG2) gene cluster on chromosome 5q32-q35 offer the opportunity to test whether these candidate genes confer susceptibility to IGEs. Our linkage analyses in 63 families ascertained through IGE patients with either juvenile myoclonic epilepsy, juvenile absence epilepsy or childhood absence epilepsy do not support the hypothesis that variants within the GABRA1 and GABRG2 gene cluster contribute a frequent major gene effect to the expression of the common familial IGEs.

Differential effect of a distractor on primary saccades and perceptual localization.

A distractor presented nearby the target of a goal-directed short latency saccade leads to spatial averaging, that is, the saccade lands between the target and the distractor. This so-called global effect is a characteristic feature of the spatial processing underlying the programming of saccadic eye movements. To determine whether this effect of near distractors on saccade metrics is also reflected in perceptual localization, subjects performed a saccade task and a perceptual localization task using identical, briefly flashed visual stimuli. To make the available visual processing time for saccades and perception more similar, we followed the target with a mask. Without the mask, primary saccades with short latency landed between target and distractor. The distractor had less effect on primary saccades with longer latencies (>200 ms) and did not affect the final eye position after late secondary saccades in the dark. This indicates that the oculomotor system can correctly use information about the target location 200 ms after the target flash even if no visual stimulus is present during this period. Likewise the presence of a distractor did not affect perceptual localization. Under the masking condition a similar global effect occurred for primary saccades with short latencies, but the latency dependence of the global effect was weakened. Secondary saccades and perceptual localization still did not show a global effect. The results suggest that the primary saccade is based on a specific target acquisition process that differs from that used for spatial perception and for the programming of memory-guided corrective saccades.

Changes in the volume of residual pituitary adenomas in patients with adult-onset growth hormone deficiency during replacement therapy with the recombinant human growth hormone.

In the course of a prospective study concerning recombinant human growth hormone replacement therapy in adult-onset growth hormone deficiency, we determined the volumes of residual tumors in six patients with pituitary macroadenomas who had formerly been treated with surgery alone or surgery and external radiotherapy. Pituitary CT scans in direct coronal views were obtained at baseline, and at 6, 12 and 18 months. The volumes of the residual tumors were calculated from the tumor diameters assuming that the tumors had an ellipsoid shape. Tumor volumes did not change in one patient and were reduced in two patients. In three patients, clinically non-significant tumor expansion by a median of 23.6 +/- 13.2% (range, 21.1-62.0%) was noted after 12 to 18 months. This tumor expansion did not cause signs or symptoms of a mass effect and did not influence further treatment. One of the six patients discontinued treatment and no further change in tumor size, as determined by MRT, was noted over a mean follow up of 34 months. Treatment was continued for up to 38 months in five patients. In four of these five patients no further change in tumor size was detected. However, treatment with the growth hormone was stopped in one patient since a 30% expansion in tumor volume, elevating the optic chiasm, was noted on MRT. None of the patients developed deterioration of visual fields. Interestingly, tumor invasion of the cavernous sinus had been present initially in all three who displayed tumor expansion while on rhGH. This first study in which diameters of residual pituitary adenomas in patients on growth hormone replacement therapy were prospectively and carefully measured, permits no conclusion regarding a causal relationship between growth hormone and tumor expansion, owing to the small number of patients. However, the observed incidence is not much different from that in former studies without growth hormone replacement therapy. Nevertheless, a close observation of the pituitary by imaging studies at regular intervals appears to be mandatory, particularly in patients with invasive residual adenomas.

Feelings of helplessness increase ERN amplitudes in healthy individuals.

Experiencing feelings of helplessness has repeatedly been reported to contribute to depressive symptoms and negative affect. In turn, depression and negative affective states are associated, among others, with impairments in performance monitoring. Thus, the question arises whether performance monitoring is also affected by feelings of helplessness. To this end, after the induction of feelings of helplessness via an unsolvable reasoning task, 37 participants (20 females) performed a modified version of a Flanker task. Based on a previously validated questionnaire, 17 participants were classified as helpless and 20 as not-helpless. Behavioral measures revealed no differences between helpless and not-helpless individuals. However, we observed enhanced Error-Related Negativity (ERN) amplitude differences between erroneous and correct responses in the helpless compared to the not-helpless group. Furthermore, correlational analysis revealed that higher scores of helplessness were associated with increased ERN difference scores. No influence of feelings of helplessness on later stages of performance monitoring was observed as indicated by Error-Positivity (Pe) amplitude. The present study is the first to demonstrate that feelings of helplessness modulate the neuronal correlates of performance monitoring. Thus, even a short-lasting subjective state manipulation can lead to ERN amplitude variation, probably via modulation of mesencephalic dopamine activity.

[Modification of dose distributions of ultra-hard X-radiation by scattering from inhomogeneities (author's transl)]. / Veränderung der Dosisverteilung ultraharter Röntgenstrahlung durch Ausstreuung aus Inhomogenitäten.

As a result of modified scattering, implants of all sorts like artificial joints, osteosynthesis nails, gold fillings in teeth, etc. the densities and ordinal numbers of which differ from that of soft tissue, cause a modification of the dose in the marginal zone of the tissues situated before the inhomogeneity. If, for example, an ultra-hard X-radiation is applied, dose increases of about 30% can be measured in the region lying in front of a steel plate.

Assessing noise annoyance: an improvement-oriented approach.

A concept for practice-oriented assessment of noise annoyance at the workplace is presented. Employees evaluated the noise situation at their workplace by characterizing the loudest noise event with respect to relevant noise characteristics. The results from a first use of the questionnaire for Subjective Evaluation of Noise Characteristics in Office Workplaces (SENO) show (1) a general need for an additional constructive measure of subjective noise annoyance, (2) that evaluation of the loudest noise event is representative for the overall workplace situation, and (3) that coping plays a crucial role and should be explicitly controlled. Finally, examples of how to use SENO for improving the workplace situation are given.

[Epileptic prodromal manifestations and episodic affective symptoms: nonspecific complaints or non-convulsive status epilepticus?]. / Epileptische Prodromi und episodische Verstimmungen: unspezifische Beschwerdebilder oder Status epilepticus non convulsivus?

Subjective unspecific complaints presage in some patients with epilepsy a following overt epileptic seizure. It has to be considered whether these epileptic prodromal states are simple partial seizures (epileptic aura) or a status epilepticus non convulsivus. Three patients with epilepsy of different classification and etiology were studied. Their interictally occurring unspezific complaints, the clinical examination and EEG with simultaneous videorecording were documented. In these three cases the results led to the conclusion that the epileptic prodromal states were the expression of a status epilepticus non convulsivus. The management and possible therapeutic intervention are discussed.

[Variability of the dose effect in the radio-biologic experimentation on animals. Second communication: influence of breed, sex, age as well as of infections on death rates and LD 50 values (author's transl)]. / Zur Variabilität des Dosiseffektes im strahlenbiologischen Tierversuch. 2. Mitteilung: Einflüsse von Rasse, Geschlecht, Alter sowie von Infektionen auf die Absterberaten und die LD-50-Werte.

As already demonstrated for Wistar rats, the radioresistance of Siv-50 male and female rats increases continually during their first months of life. Furthermore, males show a higher radioresistance than females during this period. The authors show with the same animals that a very radiosensitive rat strain can become a highly radioresistant strain after 2 1/2 years. After whole-body irradiation with 800--900 R, the increase of resistance of 85 days old males was between 62% and 68%. As a cause of this resistance increase, a mixed infection with Bordetella bronchiseptica and other germs is discussed. On the basis of literature, the authors discuss the occurrence of radioresistance increases after immunization or preconditioning with various bacterial vaccines and bacterial endotoxins.

[Variability of the dose effect in the radio-biologic experimentation on animals. Third communication: Influence of breed, sex, age as well as radiation dose on body weight and survival time in days after whole-body irradiation of Wistar and Siv-50 rats (author's transl)]. / Zur Variabilität des Dosiseffektes im strahlenbiologischen Tierversuch. 3. Mitteilung: Einfluss von Rasse, Geschlecht, Alter sowie Strahlendosis auf den Gewichtsverlauf und die Uberlebenszeit in Tagen nach Ganzkörperbestrahlung bei Wistar- und Siv-50-Ratten.

After a whole-body irradiation of Wistar and Siv-50 rat males and females with 600 to 900 R, the survival times and the development of weight of the irradiated animals were determined and compared. The development of body weight was influenced by the dose administered as well as by age, sex and breed of the animals. Furthermore, the weight curves showed also characteristic analogies. During a period of 30 days after the irradiation, there are generally two phases with a considerable weight loss which are both accompanied by a reduced absorption of drinking-water and the appearance of a gastrointestinal and hemopoietic irradiation damage as well as the resulting activity increase of the pituitary gland and the cortex of the suprarenal gland. The weight recovery occurring after sublethal radiation doses is also influenced by the administered dose and the age of the animals. The dropping weight curves of dying animals are equally dependent on the administered dose. With regard to the survival time in days in dependence upon the administered dose and the age of the animals, the authors proved that the survival time of the finally dying animals becomes longer as their radioresistance increases. During the last phase of the 30 days' experimentation, females show a markedly increased death rate whereas males seem to have continually better survival chances when they are still alive at the last phase.

[Dosimetry of a whole-body irradiation for bone marrow transplantation]. / Dosimetrie einer Ganzkörperbestrahlung zur Knochenmarkstransplantation.

The authors present a method allowing to dose a whole-body irradiation in such a way that a nearly homogenous dose of 10 Gy is reached in the whole patient, with the exception of the lung which shall only receive 8 Gy. Particular attention is given to the increased dose in the head and neck region caused by the smaller thickness as compared to the trunk, which is compensated by shields. The measurements were taken in a plastic phantom for all possible patient's dimensions. All necessary basic data are stored in a program which calculates the monitor preselection for the individual fields after input of the patient's dimensions. Further controls are intended in the near future by in-vivo measurements. The time necessary for the described measurements is about for to six days, and the same time has to be appended for the evaluation and establishment of the program.