title: The combined depletion of monoamines alters the effectiveness of subthalamic deep brain stimulation.
abstract: Non-motor symptoms of Parkinson's disease are under-studied and therefore not well treated. Here, we investigated the role of combined depletions of dopamine, norepinephrine and/or serotonin in the manifestation of motor and non-motor deficits in the rat. Then, we studied the impact of these depletions on the efficacy of deep brain stimulation of the subthalamic nucleus (STN-DBS). We performed selective depletions of dopamine, norepinephrine and serotonin, and the behavioral effects of different combined depletions were investigated using the open field, the elevated plus maze and the forced swim test. Bilateral dopamine depletion alone induced locomotor deficits associated with anxiety and mild "depressive-like" behaviors. Although additional depletions of norepinephrine and/or serotonin did not potentiate locomotor and anxiety disorders, combined depletions of the three monoamines dramatically exacerbated "depressive-like" behavior. STN-DBS markedly reversed locomotor deficits and anxiety behavior in animals with bilateral dopamine depletion alone. However, these improvements were reduced or lost by the additional depletion of norepinephrine and/or serotonin, indicating that the depletion of these monoamines may interfere with the antiparkinsonian efficacy of STN-DBS. Furthermore, our results showed that acute STN-DBS improved "depressive-like" disorder in animals with bilateral depletion of dopamine and also in animals with combined depletions of the three monoamines, which induced severe immobility in the forced swim test. Our data highlight the key role of monoamine depletions in the pathophysiology of anxiety and depressive-like disorders and provide the first evidence of their negative consequences on the efficacy of STN-DBS upon the motor and anxiety disorders in the context of Parkinson's disease.
authors.affiliation: Univ. de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, 33076 Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, 33076 Bordeaux, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Faggiani
authors.affiliation: Univ. de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, 33076 Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, 33076 Bordeaux, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Delaville
authors.affiliation: Univ. de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, 33076 Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, 33076 Bordeaux, France. Electronic address: abdelhamid.benazzouz@u-bordeaux.fr.
authors.forename: Abdelhamid
authors.initials: A
authors.lastname: Benazzouz
mesh_terms: D000818:Animals; D001008:Anxiety Disorders / Q000503:physiopathology / Q000628:therapy; D001596:Benzylamines; D015306:Biogenic Monoamines / Q000378:metabolism*; D002375:Catalepsy / Q000503:physiopathology / Q000628:therapy; D003342:Corpus Striatum / Q000378:metabolism; D046690:Deep Brain Stimulation / Q000379:methods; D003866:Depressive Disorder / Q000503:physiopathology / Q000628:therapy; D004298:Dopamine / Q000172:deficiency*; D005625:Frontal Lobe / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000502:physiology; D016627:Oxidopamine; D020734:Parkinsonian Disorders / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy*; D017207:Rats, Sprague-Dawley; D020531:Subthalamic Nucleus / Q000378:metabolism*
chemical_list: D001596:Benzylamines; D015306:Biogenic Monoamines; D016627:Oxidopamine; C012102:DSP 4; D004298:Dopamine
keywords: Anxiety behavior; Deep brain stimulation; Depressive-like behavior; Monoaminergic systems; Parkinson's disease; Subthalamic nucleus