TY - JOUR A1 - Ventura-Bort, Carlos A1 - Wirkner, Janine A1 - Genheimer, Hannah A1 - Wendt, Julia A1 - Hamm, Alfons O. A1 - Weymar, Mathias T1 - Effects of Transcutaneous Vagus Nerve Stimulation (tVNS) on the P300 and Alpha-Amylase Level: A Pilot Study JF - Frontiers in Human Neuroscience N2 - 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. KW - EEG KW - P300 KW - tVNS KW - norepinephrine KW - locus coeruleus KW - salivary alpha-amylase Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196129 SN - 1662-5161 VL - 12 IS - 202 ER - TY - JOUR A1 - Pozzi, Nicoló Gabriele A1 - Bolzoni, Francesco A1 - Biella, Gabriele Eliseo Mario A1 - Pezzoli, Gianni A1 - Ip, Chi Wang A1 - Volkmann, Jens A1 - Cavallari, Paolo A1 - Asan, Esther A1 - Isaias, Ioannis Ugo T1 - Brain noradrenergic innervation supports the development of Parkinson’s tremor: a study in a reserpinized rat model JF - Cells N2 - The pathophysiology of tremor in Parkinson’s disease (PD) is evolving towards a complex alteration to monoaminergic innervation, and increasing evidence suggests a key role of the locus coeruleus noradrenergic system (LC-NA). However, the difficulties in imaging LC-NA in patients challenge its direct investigation. To this end, we studied the development of tremor in a reserpinized rat model of PD, with or without a selective lesioning of LC-NA innervation with the neurotoxin DSP-4. Eight male rats (Sprague Dawley) received DSP-4 (50 mg/kg) two weeks prior to reserpine injection (10 mg/kg) (DR-group), while seven male animals received only reserpine treatment (R-group). Tremor, rigidity, hypokinesia, postural flexion and postural immobility were scored before and after 20, 40, 60, 80, 120 and 180 min of reserpine injection. Tremor was assessed visually and with accelerometers. The injection of DSP-4 induced a severe reduction in LC-NA terminal axons (DR-group: 0.024 ± 0.01 vs. R-group: 0.27 ± 0.04 axons/um\(^2\), p < 0.001) and was associated with significantly less tremor, as compared to the R-group (peak tremor score, DR-group: 0.5 ± 0.8 vs. R-group: 1.6 ± 0.5; p < 0.01). Kinematic measurement confirmed the clinical data (tremor consistency (% of tremor during 180 s recording), DR-group: 37.9 ± 35.8 vs. R-group: 69.3 ± 29.6; p < 0.05). Akinetic–rigid symptoms did not differ between the DR- and R-groups. Our results provide preliminary causal evidence for a critical role of LC-NA innervation in the development of PD tremor and foster the development of targeted therapies for PD patients. KW - Parkinson’s disease KW - tremor KW - locus coeruleus KW - noradrenaline KW - reserpinized rat model Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357721 SN - 2073-4409 VL - 12 IS - 21 ER - TY - JOUR A1 - Paakkari, I. A1 - Sirén, Anna-Leena A1 - Nurminen, M.-L. A1 - Svartström-Fraser, M. T1 - Injection of thyrotropin releasing hormone into the locus coeruleus increases blood pressure N2 - Thyrotropin releasing hormone (TRH), 10 pmol kg-1 injected in the region of locus coeruleus, caused a rapid (within 1 min) rise of mean arterial pressure in the urethane- naesthetized rat. No clear-cut effects in heart rate or ventilation were observed. When TRH was injected into the lateral ventricle, a dose more than 10-fold higher was required to achieve a comparable rise in arterial pressure. It is concluded that TRH may have a physiological rote in centrat cardiovascular regulation. KW - Thyreotropin-Releasinghormon KW - Blutdruck KW - Locus coeruleus KW - TRH KW - blood pressure KW - locus coeruleus Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-72894 ER - TY - JOUR A1 - Isaias, Ioannis U. A1 - Marzegan, Alberto A1 - Pezzoli, Gianni A1 - Marotta, Giorgio A1 - Canesi, Margherita A1 - Biella, Gabriele E. M. A1 - Volkmann, Jens A1 - Cavallari, Paolo T1 - A role for locus coeruleus in Parkinson tremor JF - Frontiers in Human Neuroscience N2 - We analyzed rest tremor, one of the etiologically most elusive hallmarks of Parkinson disease(PD), in 12 consecutive PD patients during a specific task activating the locus coeruleus (LC) to investigate a putative role of noradrenaline (NA) in tremor generation and suppression. Clinical diagnosis was confirmed in all subjects by reduced dopamine reuptake transporter (DAT) binding values investigated by single photon computed tomography imaging (SPECT) with [\(^{123}\)I] N-\(\omega\)-fluoropropyl-2 \(\beta\)-carbomethoxy-3 \(\beta\)-(4-iodophenyl) tropane (FP-CIT). The intensity of tremor (i.e., the power of Electromyography [EMG] signals), but not its frequency, significantly increased during the task. In six subjects, tremor appeared selectively during the task. In a second part of the study, we retrospectively reviewed SPECT with FP-CIT data and confirmed the lack of correlation between dopaminergic loss and tremor by comparing DAT binding values of 82 PD subjects with bilateral tremor (n = 27), unilateral tremor (n = 22), and no tremor (n = 33). This study suggests a role of the LC in Parkinson tremor. KW - locus coeruleus KW - disease KW - basal ganglia KW - resting tremor KW - functional neuroanatomy KW - dopamine KW - norepinephrine KW - progression KW - binding KW - rat KW - noradrenalin KW - parkinson disease KW - tremor Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133955 VL - 5 IS - 179 ER -