Telemetry based measurements of the physiological effects of stress and the role of noradrenaline in the stress response following Deep Brain Stimulation of the medial forebrain bundle

Abstract: Background: Preclinical and clinical trials have shown the short-term and long-term efficacy of in medial forebrain bundle (mfb) DBS the treatment of major depression. However, the acute physiological effects of DBS are not known. Implanted telemetry systems can be used to collect essential vital signs (ECG, heart rates, blood pressure and core temperature) from freely-moving awaked animals in realtime.Noradrenaline (NA) in the brain has been widely demonstrated as an important factor both in the stress response and in the pathogenesis of depression.
Objective: The present study consisted of two experiments; the first one was to use establish telemetry implantation in rats and use the system to collect both real-time animals’ vital signs in daily life and different behavior tests. The second one was to study the role of NA in the stress response of animals following mfb DBS by lesioning noradrenergic neurons of the locus coeruleus (LC) in the brain.
Method: For the telemetry experiment, Sprague–Dawley (SD) rats received the implanted device and were monitored up to 10 days during their sleep-awake cycles and while performing various behavior tasks. For the NA-Lesion and NA-Sham experiment, SD rats were tested on a variety of behavior tests,secondly some of the animals’ LC were partially lesioned with 6-OHDA and then received bilateral mfbDBS electrodes. Some animals also received bilateral, chronic and continuous stimulation for 7days and all the animals were tested on the same behavior tests again and were also exposed to an acute stress condition.
Results: The 6-OHDA caused a decrease of noradrenergic neurons in the LC. There was no effect of LC lesion on the open field test. The mfb DBS reduced the time and distance that animals remained in the central area during the open field test. However, in the sucrose consumption test, neither lesion nor mfb DBS had an impact on the outcome. Moreover, the mfb DBS reduced the immobility of the LC lesion group in the forced swimming test. Blood glucose or blood corticosterone levels results did not show any effect of LC lesion and mfb DBS and they had no effect on the acute stress condition response either.
Conclusion: Telemetry system was a safe and effective method in recording vital signs of the
experimental animals. 6-ODHA could cause lesions of noradrenergic neurons in the LC without other side effects. A reduction of immobility during forced swimming test in the LC-lesion group was achieved by mfb DBS. Further studies should concentrate on the mechanism of MFB DBS, in particular on the role of noradrenaline in the brain

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch
• Notes: Universität Freiburg, Dissertation, 2021

Classification and Topics

• Keyword: Symposium Major Depression - Beyond Response to Remission. 1999, Hamburg ; Noradrenaline ; Prosencephalon ; Brain stimulation

Contributors, Places and Time

• Event: Veröffentlichung
• (where): Freiburg
• (who): Universität
• (when): 2021
• Creator: Zhang, Yu
• Contributor: Coenen, Volker Arnd ; Albert-Ludwigs-Universität Freiburg. Medizinische Fakultät

Further information

• DOI: 10.6094/UNIFR/222565
• URN: urn:nbn:de:bsz:25-freidok-2225654
• Rights: Kein Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 15.08.2025, 7:32 AM CEST