Conditioning of the early behavioral response to apomorphine in the rotational model of Parkinson's disease

The rotational model of Parkinson's disease has been widely used to investigate the action of dopamine agonists. This animal model involves the production of a unilateral nigrostriatal lesion in rats. The lesion is produced with 6-hydroxydopamine which causes dopamine depletion and subsequent supersensitivity of striatal receptors. Thus, administration of drugs which are therapeutically effective in Parkinson's disease, elicits circling behavior contralateral to the lesioned side. The origin of the paradoxical response and the undrugged rotations observed after saline injections in apomorphine pretreated rats has not been explained. We report here that the undrugged response can be associated with the early rotational response elicited by the drug. Furthermore, we show the effect of inhibitory conditioning on this early response. Our results suggest that pharmacological conditioning plays a significant role in the modification of the therapeutic effectiveness of CNS-active drugs after extended treatments.     

Connectivity patterns during music listening: Evidence for action‐based processing in musicians

Musical expertise is visible both in the morphology and functionality of the brain. Recent research indicates that functional integration between multi‐sensory, somato‐motor, default‐mode (DMN), and salience (SN) networks of the brain differentiates musicians from non‐musicians during resting state. Here, we aimed at determining whether brain networks differentially exchange information in musicians as opposed to non‐musicians during naturalistic music listening. Whole‐brain graph‐theory analyses were performed on participants' fMRI responses. Group‐level differences revealed that musicians' primary hubs comprised cerebral and cerebellar sensorimotor regions whereas non‐musicians' dominant hubs encompassed DMN‐related regions. Community structure analyses of the key hubs revealed greater integration of motor and somatosensory homunculi representing the upper limbs and torso in musicians. Furthermore, musicians who started training at an earlier age exhibited greater centrality in the auditory cortex, and areas related to top‐down processes, attention, emotion, somatosensory processing, and non‐verbal processing of speech. We here reveal how brain networks organize themselves in a naturalistic music listening situation wherein musicians automatically engage neural networks that are action‐based while non‐musicians use those that are perception‐based to process an incoming auditory stream. Hum Brain Mapp 38:2955–2970, 2017. © 2017 Wiley Periodicals, Inc.     

A low cost fMRI-compatible tracking system using the Nintendo Wii remote

It is sometimes necessary during functional magnetic resonance imaging (fMRI) experiments to capture different movements made by the subjects, e.g. to enable them to control an item or to analyze its kinematics. The aim of this work is to present an inexpensive hand tracking system suitable for use in a high field MRI environment. It works by introducing only one light-emitting diode (LED) in the magnet room, and by receiving its signal with a Nintendo Wii remote (the primary controller for the Nintendo Wii console) placed outside in the control room. Thus, it is possible to take high spatial and temporal resolution registers of a moving point that, in this case, is held by the hand. We tested it using a ball and racket virtual game inside a 3 Tesla MRI scanner to demonstrate the usefulness of the system. The results show the involvement of a number of areas (mainly occipital and frontal, but also parietal and temporal) when subjects are trying to stop an object that is approaching from a first person perspective, matching previous studies performed with related visuomotor tasks. The system presented here is easy to implement, easy to operate and does not produce important head movements or artifacts in the acquired images. Given its low cost and ready availability, the method described here is ideal for use in basic and clinical fMRI research to track one or more moving points that can correspond to limbs, fingers or any other object whose position needs to be known.     

Prediction of surgical risk in patients with endocarditis: Comparison of logistic EuroSCORE,EuroSCORE II and APORTEI score

ObjectivesAPORTEI score is a new risk prediction model for patients with infective endocarditis. It has been recently validated on a Spanish multicentric national cohort of patients. The aim of the present study is to compare APORTEI performances with logistic EuroSCORE and EuroSCORE II by testing calibration and discrimination on a local sample population underwent cardiac surgery because of endocarditis.MethodsWe tested three prediction scores on 111 patients underwent surgery from 2014 to 2020 at our Institution because of infective endocarditis. Area under the curves and Hosmer–Lemeshow test were used to analyze discrimination and calibration respectively of logistic EuroSCORE, EuroSCORE II and APORTEI score.ResultsThe overall observed one-month mortality rate was 21.6%. The observed-to-expected ratio was 1.27 for logistic EuroSCORE, 3.27 for EuroSCORE II and 0.94 for APORTEI. The area under the curve (AUC) value of APORTEI (0.88 ± 0.05) was significantly higher than that one of logistic EuroSCORE (AUC 0.77 ± 0.05; p 0.0001) and of EuroSCORE II (AUC 0.74 ± 0.05; p 0.0005). Hosmer–Lemeshow test showed better calibration performance of the APORTEI, (logistic EuroSCORE: p 0.19; EuroSCORE II: p 0.11; APORTEI: p 0.56).ConclusionAPORTEI risk score shows significantly higher performances in term of discrimination and calibration compared with both logistic EuroSCORE and EuroSCORE II.     

Conditioning the placebo response in the rotational model of Parkinson's disease

Persistent behavioural effect of the direct dopamine receptors agonist apomorphine in the rotational model of Parkinson's disease was investigated. We show how this placebo response can be considered an extraordinary example of environment-drug associative learning and how it can be related to a critical point of the time-course response to the drug after repeated administration. Classical conditioning of "placebo response" in an animal model of a neurological or psychiatric disease had not been reported previously.