title: Sensory and cognitive neurophysiology in rats, Part 1: Controlled tactile stimulation and micro-ECoG recordings in freely moving animals.
abstract: BACKGROUND
  We have developed a setup for rats that allows for controlled sensory input to an animal engaged in a task while recording both electrophysiological signals and behavioral output.
  
  
  METHODS
  We record electrophysiological signals using a novel high-density micro-electrocorticography (micro-ECoG) grid that covers almost the whole somatosensory system. We dealt with the well-known difficulty that the rat uses its whisker system in an active (motor-controlled) way to explore its environment by designing a head-mounted device that stimulates the rat's snout in a way unaffected by whisker movements.
  
  
  RESULTS
  We replicate the spatial specificity of early evoked responses in somatosensory and auditory cortex. In a companion paper (Cognitive Neurophysiology in Rats, Part 2: Validation and Demonstration) we validate our setup and show for the first time that the ECoG can be used to record evoked responses in a signal that reflects neural output (spiking activity).
  
  
  METHODS
  Compared with high-density wire recordings, micro-ECoG offers a much more stable signal without readjustments, and a much better scalability. Compared with head-fixed preparations, our head-mounted stimulator allows to stay closer to the rat's natural way of collecting sensory information.
  
  
  CONCLUSIONS
  For perceptual and cognitive research, our setup provides a unique combination of possibilities that cannot be achieved in other setups for rodents.
authors.affiliation: Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, The Netherlands.
authors.forename: George
authors.initials: G
authors.lastname: Dimitriadis
authors.affiliation: Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, The Netherlands.
authors.forename: Anne M M
authors.initials: AM
authors.lastname: Fransen
authors.affiliation: Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, The Netherlands. Electronic address: e.maris@donders.ru.nl.
authors.forename: Eric
authors.initials: E
authors.lastname: Maris
mesh_terms: D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D001931:Brain Mapping / Q000295:instrumentation / Q000379:methods; D003071:Cognition / Q000502:physiology*; D004569:Electroencephalography; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D021621:Imaging, Three-Dimensional; D008297:Male; D009482:Neurophysiology / Q000295:instrumentation / Q000379:methods; D010812:Physical Stimulation; D051381:Rats; D020318:Rats, Long-Evans; D013028:Space Perception / Q000502:physiology; D014110:Touch / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology*
keywords: Barrel cortex; Electrophysiology; Head-mounted tactile stimulation; Micro-ECoG; Multi-unit activity; Rat; Somatosensory system