TY - JOUR A1 - Hahn, Tim A1 - Dresler, Thomas A1 - Pyka, Martin A1 - Notebaert, Karolien A1 - Fallgatter, Andreas J. T1 - Local Synchronization of Resting-State Dynamics Encodes Gray's Trait Anxiety JF - PLoS ONE N2 - The Behavioral Inhibition System (BIS) as defined within the Reinforcement Sensitivity Theory (RST) modulates reactions to stimuli indicating aversive events. Gray's trait Anxiety determines the extent to which stimuli activate the BIS. While studies have identified the amygdala-septo-hippocampal circuit as the key-neural substrate of this system in recent years and measures of resting-state dynamics such as randomness and local synchronization of spontaneous BOLD fluctuations have recently been linked to personality traits, the relation between resting-state dynamics and the BIS remains unexplored. In the present study, we thus examined the local synchronization of spontaneous fMRI BOLD fluctuations as measured by Regional Homogeneity (ReHo) in the hippocampus and the amygdala in twenty-seven healthy subjects. Correlation analyses showed that Gray's trait Anxiety was significantly associated with mean ReHo in both the amygdala and the hippocampus. Specifically, Gray's trait Anxiety explained 23% and 17% of resting-state ReHo variance in the left amygdala and the left hippocampus, respectively. In summary, we found individual differences in Gray's trait Anxiety to be associated with ReHo in areas previously associated with BIS functioning. Specifically, higher ReHo in resting-state neural dynamics corresponded to lower sensitivity to punishment scores both in the amygdala and the hippocampus. These findings corroborate and extend recent findings relating resting-state dynamics and personality while providing first evidence linking properties of resting-state fluctuations to Gray's BIS. KW - reward KW - bold activity KW - amygdala KW - brain KW - personality KW - sensitivity KW - punishment KW - dimensions KW - modulation KW - predict Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131057 VL - 8 IS - 3 ER - TY - JOUR A1 - Kollert, Sina A1 - Dombert, Benjamin A1 - Döring, Frank A1 - Wischmeyer, Erhard T1 - Activation of TRESK channels by the inflammatory mediator lysophosphatidic acid balances nociceptive signalling JF - Scientific Reports N2 - In dorsal root ganglia (DRG) neurons TRESK channels constitute a major current component of the standing outward current IK\(_{SO}\). A prominent physiological role of TRESK has been attributed to pain sensation. During inflammation mediators of pain e.g. lysophosphatidic acid (LPA) are released and modulate nociception. We demonstrate co-expression of TRESK and LPA receptors in DRG neurons. Heterologous expression of TRESK and LPA receptors in Xenopus oocytes revealed augmentation of basal K\(^{+}\) currents upon LPA application. In DRG neurons nociception can result from TRPV\(_{1}\) activation by capsaicin or LPA. Upon co-expression in Xenopus oocytes LPA simultaneously increased both depolarising TRPV\(_{1}\) and hyperpolarising TRESK currents. Patch-clamp recordings in cultured DRG neurons from TRESK[wt] mice displayed increased IK\(_{SO}\) after application of LPA whereas under these conditions IK\(_{SO}\) in neurons from TRESK[ko] mice remained unaltered. Under current-clamp conditions LPA application differentially modulated excitability in these genotypes upon depolarising pulses. Spike frequency was attenuated in TRESK[wt] neurons and, in contrast, augmented in TRESK[ko] neurons. Accordingly, excitation of nociceptive neurons by LPA is balanced by co-activation of TRESK channels. Hence excitation of sensory neurons is strongly controlled by the activity of TRESK channels, which therefore are good candidates for the treatment of pain disorders. KW - protein coupled receptors KW - molecular mechanisms KW - neuropathic pain KW - migraine KW - initiation KW - modulation KW - cells KW - sensory neurons KW - domain K\(^{+}\) channels KW - 2-pore potassium channel Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148312 VL - 5 IS - 12548 ER - TY - JOUR A1 - Kohl, S. A1 - Gruendler, T. O. J. A1 - Huys, D. A1 - Sildatke, E. A1 - Dembek, T. A. A1 - Hellmich, M. A1 - Vorderwulbecke, M. A1 - Timmermann, L. A1 - Ahmari, S. E. A1 - Klosterkoetter, J. A1 - Jessen, F. A1 - Sturm, V. A1 - Visser-Vandewalle, V. A1 - Kuhn, J. T1 - Effects of deep brain stimulation on prepulse inhibition in obsessive-compulsive disorder JF - Translational Psychiatry N2 - Owing to a high response rate, deep brain stimulation (DBS) of the ventral striatal area has been approved for treatment-refractory obsessive-compulsive disorder (tr-OCD). Many basic issues regarding DBS for tr-OCD are still not understood, in particular, the mechanisms of action and the origin of side effects. We measured prepulse inhibition (PPI) in treatment-refractory OCD patients undergoing DBS of the nucleus accumbens (NAcc) and matched controls. As PPI has been used in animal DBS studies, it is highly suitable for translational research. Eight patients receiving DBS, eight patients with pharmacological treatment and eight age-matched healthy controls participated in our study. PPI was measured twice in the DBS group: one session with the stimulator switched on and one session with the stimulator switched off. OCD patients in the pharmacologic group took part in a single session. Controls were tested twice, to ensure stability of data. Statistical analysis revealed significant differences between controls and (1) patients with pharmacological treatment and (2) OCD DBS patients when the stimulation was switched off. Switching the stimulator on led to an increase in PPI at a stimulus-onset asynchrony of 200 ms. There was no significant difference in PPI between OCD patients being stimulated and the control group. This study shows that NAcc-DBS leads to an increase in PPI in tr-OCD patients towards a level seen in healthy controls. Assuming that PPI impairments partially reflect the neurobiological substrates of OCD, our results show that DBS of the NAcc may improve sensorimotor gating via correction of dysfunctional neural substrates. Bearing in mind that PPI is based on a complex and multilayered network, our data confirm that DBS most likely takes effect via network modulation. KW - nucleus KW - serotonin KW - schizophrenia KW - dopamine KW - double-blind KW - psychiatric disorders KW - in vivo KW - acoustic startle KW - reflex KW - modulation Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-138300 VL - 5 IS - e675 ER - TY - JOUR A1 - Schilcher, Felix A1 - Thamm, Markus A1 - Strube-Bloss, Martin A1 - Scheiner, Ricarda T1 - Opposing actions of octopamine and tyramine on honeybee vision JF - Biomolecules N2 - The biogenic amines octopamine and tyramine are important neurotransmitters in insects and other protostomes. They play a pivotal role in the sensory responses, learning and memory and social organisation of honeybees. Generally, octopamine and tyramine are believed to fulfil similar roles as their deuterostome counterparts epinephrine and norepinephrine. In some cases opposing functions of both amines have been observed. In this study, we examined the functions of tyramine and octopamine in honeybee responses to light. As a first step, electroretinography was used to analyse the effect of both amines on sensory sensitivity at the photoreceptor level. Here, the maximum receptor response was increased by octopamine and decreased by tyramine. As a second step, phototaxis experiments were performed to quantify the behavioural responses to light following treatment with either amine. Octopamine increased the walking speed towards different light sources while tyramine decreased it. This was independent of locomotor activity. Our results indicate that tyramine and octopamine act as functional opposites in processing responses to light. KW - biogenic amines KW - neurotransmitter KW - phototaxis KW - ERG KW - behaviour KW - modulation KW - visual system KW - octopamine KW - tyramine KW - Apis mellifera Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-246214 SN - 2218-273X VL - 11 IS - 9 ER -