Biology subjects

Pepping, G.-J.

Publications and source records attributed to Pepping, G.-J..

3 recordsLinked to original sources

bioRxiv2018

Prospective control of movement in the basal ganglia

Neural systems control purposeful movements both within an animals body (e.g., pumping blood) and in the environment (e.g., reaching). This is vital for all animals. The movement control functions of globus pallidus (GP), subthalamic nucleus (STN) and zona incerta (ZI) were analyzed in monkeys reaching for seen targets. Temporal profiles of their hand movements and the synchronized pattern of neuropower (rate of flow of electrochemical energy) through the basal ganglia were analyzed in terms of general tau theory of movement control (Lee et al., 2009), using the variable rho (=1/tau). The results suggest: (i) the neuroinformation for controlling movement is the relative-rate-of-change, rho, of neuropower in the nervous system; (ii) GP is involved in creating prescriptive rhos of neuropower to guide movements; (iii) STN is involved in registering perceptual rhos of neuropower to monitor the movement; (iv) ZI is involved in combining the prescriptive and perceptual rhos of neuropower to generate performatory rhos of neuropower to activate the muscles to produce the movement. Possible implications for Parkinsons disease are discussed.

neuroscience↗

bioRxiv2017

Improving tauG-Control Of Action In PD

A theory of action control (General Tau Theory) is applied to analyzing normal and abnormal movements in PD; and to designing and testing the efficacy of a sonic aid for PD. A central aspect of the theory, which is supported by experimental evidence across a variety of actions and species, is that the trajectories of competent skilled actions follow a particular temporal pattern, which is described by the mathematical function, tauG. Since tauG-control of actions can be largely deficient in PD, we designed a device that generates whoop-like sounds, where the fundamental frequency of the sound follows the tauG pattern. Our hypothesis was that by listening to these sounds the nervous system of someone with PD might be helped subsequently to self-generate tauG patterns in their nervous system, which might facilitate movement control in different situations. Five adults with PD, and five age-matched controls, took part in the study. They each listened to the sounds under two conditions: (a) experimental - turning a handle for 5 minutes while the sounds were played (b) control - turning the handle without the sounds. Before and after each condition, the tauG-control of lateral body sway while standing was measured (without the sounds playing), using force-plates, on two tasks: (i) keeping the feet down, (ii) lifting the trailing foot. The number of participants out of five, who showed greater ratio improvement following practice with whoop sounds compared to without sounds, was, on each task, high for the PDs compared with the age-matched controls (4 vs 2 or 3). Thus, for the PDs, listening to the tauG whoop-like sounds while performing one action (handle turning) improved subsequent tauG-control on a different task (body-swaying).

neuroscience↗

bioRxiv2017

Function of basal ganglia in tauG-guiding action

Nervous systems control purposeful movement, both within and outside the body, which is essential for the survival of an animal. The movement control functions of globus pallidus (GP), subthalamic nucleus (STN) and zona incerta (ZI) were analyzed in monkeys reaching for seen targets. Temporal profiles of the hand movements of monkeys and the synchronized flow of electrochemical energy through these basal ganglia were analyzed in terms of a theory of goal-directed movement. Theoretical and empirical analysis indicated: (i) the neural information for controlling movement is the relative-rate-of-change of flow of electrochemical energy in neurons rather than the flow itself; (ii) GP is involved in creating prospective electrochemical flow to guide movement; (iii) STN is involved in registering the perceptual electrochemical flow monitoring the movement; (iv) ZI is involved in integrating the prospective and perceptual electrochemical flows to power the muscles and thence the movement. Possible implications for PD are discussed.

neuroscience↗