@article{VenturaBortWirknerGenheimeretal.2018, author = {Ventura-Bort, Carlos and Wirkner, Janine and Genheimer, Hannah and Wendt, Julia and Hamm, Alfons O. and Weymar, Mathias}, title = {Effects of Transcutaneous Vagus Nerve Stimulation (tVNS) on the P300 and Alpha-Amylase Level: A Pilot Study}, series = {Frontiers in Human Neuroscience}, volume = {12}, journal = {Frontiers in Human Neuroscience}, number = {202}, issn = {1662-5161}, doi = {10.3389/fnhum.2018.00202}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196129}, year = {2018}, abstract = {Recent research suggests that the P3b may be closely related to the activation of the locus coeruleus-norepinephrine (LC-NE) system. To further study the potential association, we applied a novel technique, the non-invasive transcutaneous vagus nerve stimulation (tVNS), which is speculated to increase noradrenaline levels. Using a within-subject cross-over design, 20 healthy participants received continuous tVNS and sham stimulation on two consecutive days (stimulation counterbalanced across participants) while performing a visual oddball task. During stimulation, oval non-targets (standard), normal-head (easy) and rotated-head (difficult) targets, as well as novel stimuli (scenes) were presented. As an indirect marker of noradrenergic activation we also collected salivary alpha-amylase (sAA) before and after stimulation. Results showed larger P3b amplitudes for target, relative to standard stimuli, irrespective of stimulation condition. Exploratory post hoc analyses, however, revealed that, in comparison to standard stimuli, easy (but not difficult) targets produced larger P3b (but not P3a) amplitudes during active tVNS, compared to sham stimulation. For sAA levels, although main analyses did not show differential effects of stimulation, direct testing revealed that tVNS (but not sham stimulation) increased sAA levels after stimulation. Additionally, larger differences between tVNS and sham stimulation in P3b magnitudes for easy targets were associated with larger increase in sAA levels after tVNS, but not after sham stimulation. Despite preliminary evidence for a modulatory influence of tVNS on the P3b, which may be partly mediated by activation of the noradrenergic system, additional research in this field is clearly warranted. Future studies need to clarify whether tVNS also facilitates other processes, such as learning and memory, and whether tVNS can be used as therapeutic tool.}, language = {en} } @article{FarmerStrzelczykFinisguerraetal.2021, author = {Farmer, Adam D. and Strzelczyk, Adam and Finisguerra, Alessandra and Gourine, Alexander V. and Gharabaghi, Alireza and Hasan, Alkomiet and Burger, Andreas M. and Jaramillo, Andr{\´e}s M. and Mertens, Ann and Majid, Arshad and Verkuil, Bart and Badran, Bashar W. and Ventura-Bort, Carlos and Gaul, Charly and Beste, Christian and Warren, Christopher M. and Quintana, Daniel S. and H{\"a}mmerer, Dorothea and Freri, Elena and Frangos, Eleni and Tobaldini, Eleonora and Kaniusas, Eugenijus and Rosenow, Felix and Capone, Fioravante and Panetsos, Fivos and Ackland, Gareth L. and Kaithwas, Gaurav and O'Leary, Georgia H. and Genheimer, Hannah and Jacobs, Heidi I. L. and Van Diest, Ilse and Schoenen, Jean and Redgrave, Jessica and Fang, Jiliang and Deuchars, Jim and Sz{\´e}les, Jozsef C. and Thayer, Julian F. and More, Kaushik and Vonck, Kristl and Steenbergen, Laura and Vianna, Lauro C. and McTeague, Lisa M. and Ludwig, Mareike and Veldhuizen, Maria G. and De Couck, Marijke and Casazza, Marina and Keute, Marius and Bikson, Marom and Andreatta, Marta and D'Agostini, Martina and Weymar, Mathias and Betts, Matthew and Prigge, Matthias and Kaess, Michael and Roden, Michael and Thai, Michelle and Schuster, Nathaniel M. and Montano, Nicola and Hansen, Niels and Kroemer, Nils B. and Rong, Peijing and Fischer, Rico and Howland, Robert H. and Sclocco, Roberta and Sellaro, Roberta and Garcia, Ronald G. and Bauer, Sebastian and Gancheva, Sofiya and Stavrakis, Stavros and Kampusch, Stefan and Deuchars, Susan A. and Wehner, Sven and Laborde, Sylvain and Usichenko, Taras and Polak, Thomas and Zaehle, Tino and Borges, Uirassu and Teckentrup, Vanessa and Jandackova, Vera K. and Napadow, Vitaly and Koenig, Julian}, title = {International Consensus Based Review and Recommendations for Minimum Reporting Standards in Research on Transcutaneous Vagus Nerve Stimulation (Version 2020)}, series = {Frontiers in Human Neuroscience}, volume = {14}, journal = {Frontiers in Human Neuroscience}, issn = {1662-5161}, doi = {10.3389/fnhum.2020.568051}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234346}, year = {2021}, abstract = {Given its non-invasive nature, there is increasing interest in the use of transcutaneous vagus nerve stimulation (tVNS) across basic, translational and clinical research. Contemporaneously, tVNS can be achieved by stimulating either the auricular branch or the cervical bundle of the vagus nerve, referred to as transcutaneous auricular vagus nerve stimulation(VNS) and transcutaneous cervical VNS, respectively. In order to advance the field in a systematic manner, studies using these technologies need to adequately report sufficient methodological detail to enable comparison of results between studies, replication of studies, as well as enhancing study participant safety. We systematically reviewed the existing tVNS literature to evaluate current reporting practices. Based on this review, and consensus among participating authors, we propose a set of minimal reporting items to guide future tVNS studies. The suggested items address specific technical aspects of the device and stimulation parameters. We also cover general recommendations including inclusion and exclusion criteria for participants, outcome parameters and the detailed reporting of side effects. Furthermore, we review strategies used to identify the optimal stimulation parameters for a given research setting and summarize ongoing developments in animal research with potential implications for the application of tVNS in humans. Finally, we discuss the potential of tVNS in future research as well as the associated challenges across several disciplines in research and clinical practice.}, language = {en} } @article{GenheimerAndreattaAsanetal.2017, author = {Genheimer, Hannah and Andreatta, Marta and Asan, Esther and Pauli, Paul}, title = {Reinstatement of contextual conditioned anxiety in virtual reality and the effects of transcutaneous vagus nerve stimulation in humans}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, number = {17886}, doi = {10.1038/s41598-017-18183-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169892}, year = {2017}, abstract = {Since exposure therapy for anxiety disorders incorporates extinction of contextual anxiety, relapses may be due to reinstatement processes. Animal research demonstrated more stable extinction memory and less anxiety relapse due to vagus nerve stimulation (VNS). We report a valid human three-day context conditioning, extinction and return of anxiety protocol, which we used to examine effects of transcutaneous VNS (tVNS). Seventy-five healthy participants received electric stimuli (unconditioned stimuli, US) during acquisition (Day1) when guided through one virtual office (anxiety context, CTX+) but never in another (safety context, CTX-). During extinction (Day2), participants received tVNS, sham, or no stimulation and revisited both contexts without US delivery. On Day3, participants received three USs for reinstatement followed by a test phase. Successful acquisition, i.e. startle potentiation, lower valence, higher arousal, anxiety and contingency ratings in CTX+ versus CTX-, the disappearance of these effects during extinction, and successful reinstatement indicate validity of this paradigm. Interestingly, we found generalized reinstatement in startle responses and differential reinstatement in valence ratings. Altogether, our protocol serves as valid conditioning paradigm. Reinstatement effects indicate different anxiety networks underlying physiological versus verbal responses. However, tVNS did neither affect extinction nor reinstatement, which asks for validation and improvement of the stimulation protocol.}, language = {en} } @phdthesis{Genheimer2020, author = {Genheimer, Hannah}, title = {The acquisition of anxiety and the impact of transcutaneous vagus nerve stimulation on extinction learning in virtual contexts}, doi = {10.25972/OPUS-20639}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-206390}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {This thesis aims for a better understanding of the mechanisms underlying anxiety as well as trauma- and stressor-related disorders and the development of new therapeutic approaches. I was first interested in the associative learning mechanisms involved in the etiology of anxiety disorders. Second, I explored the therapeutic effects of transcutaneous vagus nerve stimulation (tVNS) as a promising new method to accelerate and stabilize extinction learning in humans. For these purposes, I applied differential anxiety conditioning protocols realized by the implementation of virtual reality (VR). Here, a formerly neutral virtual context (anxiety context, CTX+) is presented whereby the participants unpredictably receive mildly aversive electric stimuli (unconditioned stimulus, US). Another virtual context (safety context, CTX-) is never associated with the US. Moreover, extinction of conditioned anxiety can be modeled by presenting the same contexts without US delivery. When unannounced USs were administered after extinction, i.e. reinstatement, the strength of the "returned" conditioned anxiety can provide information on the stability of the extinction memory. In Study 1, I disentangled the role of elemental and conjunctive context representations in the acquisition of conditioned anxiety. Sequential screenshots of two virtual offices were presented like a flip-book so that I elicited the impression of walking through the contexts. Some pictures of CTX+ were paired with an US (threat elements), but not some other screenshots of the same context (non-threat elements), nor the screenshots depicting CTX- (safety elements). Higher contingency ratings for threat compared to non-threat elements revealed elemental representation. Electro-cortical responses showed larger P100 and early posterior negativity amplitudes elicited by screenshots depicting CTX+ compared to CTX- and suggested conjunctive representation. These results support the dual context representation in anxiety acquisition in healthy individuals. Study 2 addressed the effects of tVNS on the stabilization of extinction learning by using a context conditioning paradigm. Potentiated startle responses as well as higher aversive ratings in CTX+ compared to CTX- indicate successful anxiety conditioning. Complete extinction was found in startle responses and valence ratings as no differentiation between CTX+ and CTX- suggested. TVNS did not affect extinction or reinstatement of anxiety which may be related to the inappropriate transferability of successful stimulation parameters from epilepsy patients to healthy participants during anxiety extinction. Therefore, in Study 3 I wanted to replicate the modulatory effects of tVNS on heart rate and pain perception by the previously used parameters. However, no effects of tVNS were observed on subjective pain ratings, on pain tolerance, or on heart rate. This led to the conclusion that the modification of stimulation parameters is necessary for a successful acceleration of anxiety extinction in humans. In Study 4, I prolonged the tVNS and, considering previous tVNS studies, I applied a cue conditioning paradigm in VR. Therefore, during acquisition a cue (CS+) presented in CTX+ predicted the US, but not another cue (CS-). Both cues were presented in a second context (CTX-) and never paired with the US. Afterward, participants received either tVNS or sham stimulation and underwent extinction learning. I found context-dependent cue conditioning only in valence ratings, which was indicated by lower valence for CS+ compared to CS- in CTX+, but no differential ratings in CTX-. Successful extinction was indicated by equal responses to CS+ and CS-. Interestingly, I found reinstatement of conditioned fear in a context-dependent manner, meaning startle response was potentiated for CS+ compared to CS- only in the anxiety context. Importantly, even the prolonged tVNS had no effect, neither on extinction nor on reinstatement of context-dependent cue conditioning. However, I found first evidence for accelerated physiological contextual extinction due to less differentiation between startles in CTX+ compared to CTX- in the tVNS than in the sham stimulated group. In sum, this thesis first confirms the dual representation of a context in an elemental and a conjunctive manner. Second, though anxiety conditioning and context-dependent cue conditioning paradigms worked well, the translation of tVNS accelerated extinction from rats to humans needs to be further developed, especially the stimulation parameters. Nevertheless, tVNS remains a very promising approach of memory enhancement, which can be particularly auspicious in clinical settings.}, subject = {Angst}, language = {en} }