Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Life Sciences
Rules And Mechanisms For Efficient Two-Stage Learning In Neural Circuits, Tiberiu Teşileanu, Bence Ölveczky, Vijay Balasubramanian
Rules And Mechanisms For Efficient Two-Stage Learning In Neural Circuits, Tiberiu Teşileanu, Bence Ölveczky, Vijay Balasubramanian
Publications and Research
Trial-and-error learning requires evaluating variable actions and reinforcing successful variants. In songbirds, vocal exploration is induced by LMAN, the output of a basal ganglia-related circuit that also contributes a corrective bias to the vocal output. This bias is gradually consolidated in RA, a motor cortex analogue downstream of LMAN. We develop a new model of such two-stage learning. Using stochastic gradient descent, we derive how the activity in ‘tutor’ circuits (e.g., LMAN) should match plasticity mechanisms in ‘student’ circuits (e.g., RA) to achieve efficient learning. We further describe a reinforcement learning framework through which the tutor can build its teaching …
Striatal Dopaminergic Innervation Regulates Subthalamic Beta-Oscillations And Cortical-Subcortical Coupling During Movements: Preliminary Evidence In Subjects With Parkinson’S Disease, Andrea Canessa, Nicolo G. Pozzi, Gabriele Arnulfo, Joachim Brumberg, Martin M. Reich, Gianni Pezzoli, Maria F. Ghilardi, Cordula Matthies, Frank Steigerwald, Jens Volkman, Ioannis U. Isais
Striatal Dopaminergic Innervation Regulates Subthalamic Beta-Oscillations And Cortical-Subcortical Coupling During Movements: Preliminary Evidence In Subjects With Parkinson’S Disease, Andrea Canessa, Nicolo G. Pozzi, Gabriele Arnulfo, Joachim Brumberg, Martin M. Reich, Gianni Pezzoli, Maria F. Ghilardi, Cordula Matthies, Frank Steigerwald, Jens Volkman, Ioannis U. Isais
Publications and Research
Activation of the basal ganglia has been shown during the preparation and execution of movement. However, the functional interaction of cortical and subcortical brain areas during movement and the relative contribution of dopaminergic striatal innervation remains unclear. We recorded local field potential (LFP) activity from the subthalamic nucleus (STN) and high-density electroencephalography (EEG) signals in four patients with Parkinson’s disease (PD) off dopaminergic medication during a multi-joint motor task performed with their dominant and non-dominant hand. Recordings were performed by means of a fully-implantable deep brain stimulation (DBS) device at 4 months after surgery. Three patients also performed a single-photon …
Corticospinal And Reciprocal Inhibition Actions On Human Soleus Motoneuron Activity During Standing And Walking, Berthe Hanna-Boutros, Sina Sangari, Louis-Solal Giboin, Mohamed-Mounir El Mendili, Alexandra Lackmy-Vallée, Véronique Marchand-Pauvert, Maria Knikou
Corticospinal And Reciprocal Inhibition Actions On Human Soleus Motoneuron Activity During Standing And Walking, Berthe Hanna-Boutros, Sina Sangari, Louis-Solal Giboin, Mohamed-Mounir El Mendili, Alexandra Lackmy-Vallée, Véronique Marchand-Pauvert, Maria Knikou
Publications and Research
Reciprocal Ia inhibition constitutes a key segmental neuronal pathway for coordination of antagonist muscles. In this study, we investigated the soleus H-reflex and reciprocal inhibition exerted from flexor group Ia afferents on soleus motoneurons during standing and walking in 15 healthy subjects following transcranial magnetic stimulation (TMS). The effects of separate TMS or deep peroneal nerve (DPN) stimulation and the effects of combined (TMS + DPN) stimuli on the soleus H-reflex were assessed during standing and at mid- and late stance phases of walking. Subthreshold TMS induced short-latency facilitation on the soleus H-reflex that was present during standing and at …