title: A video based feedback system for control of an active commutator during behavioral physiology.
abstract: BACKGROUND
  To investigate the relationship between neural function and behavior it is necessary to record neuronal activity in the brains of freely behaving animals, a technique that typically involves tethering to a data acquisition system. Optimally this approach allows animals to behave without any interference of movement or task performance. Currently many laboratories in the cognitive and behavioral neuroscience fields employ commercial motorized commutator systems using torque sensors to detect tether movement induced by the trajectory behaviors of animals.
  
  
  RESULTS
  In this study we describe a novel motorized commutator system which is automatically controlled by video tracking. To obtain accurate head direction data two light emitting diodes were used and video image noise was minimized by physical light source manipulation. The system calculates the rotation of the animal across a single trial by processing head direction data and the software, which calibrates the motor rotation angle, subsequently generates voltage pulses to actively untwist the tether. This system successfully provides a tether twist-free environment for animals performing behavioral tasks and simultaneous neural activity recording.
  
  
  CONCLUSIONS
  To the best of our knowledge, it is the first to utilize video tracking generated head direction to detect tether twisting and compensate with a motorized commutator system. Our automatic commutator control system promises an affordable and accessible method to improve behavioral neurophysiology experiments, particularly in mice.
authors.affiliation: Department of Anatomy, Brain Science & Engineering Institute, Behavioral Neural Circuitry and Physiology Laboratory, Kyungpook National University Graduate School of Medicine, 2-101, Dongin-dong, Jung-gu, Daegu, 700-842, South Korea.
authors.forename: Mootaek
authors.initials: M
authors.lastname: Roh
authors.affiliation: Laboratory for Circuit and Behavioral Physiology, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: McHugh
authors.affiliation: Department of Anatomy, Brain Science & Engineering Institute, Behavioral Neural Circuitry and Physiology Laboratory, Kyungpook National University Graduate School of Medicine, 2-101, Dongin-dong, Jung-gu, Daegu, 700-842, South Korea. irislkm@knu.ac.kr.
authors.forename: Kyungmin
authors.initials: K
authors.lastname: Lee
mesh_terms: D000465:Algorithms; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D002138:Calibration; D025461:Feedback, Physiological; D008297:Male; D008810:Mice, Inbred C57BL; D010827:Physiology / Q000295:instrumentation*; D012399:Rotation; D059629:Signal-To-Noise Ratio; D013647:Task Performance and Analysis; D014741:Video Recording