title: An optimized surgical approach for obtaining stable extracellular single-unit recordings from the cerebellum of head-fixed behaving mice.
abstract: BACKGROUND
  Electrophysiological recording approaches are essential for understanding brain function. Among these approaches are various methods of performing single-unit recordings. However, a major hurdle to overcome when recording single units in vivo is stability. Poor stability results in a low signal-to-noise ratio, which makes it challenging to isolate neuronal signals. Proper isolation is needed for differentiating a signal from neighboring cells or the noise inherent to electrophysiology. Insufficient isolation makes it impossible to analyze full action potential waveforms. A common source of instability is an inadequate surgery. Problems during surgery cause blood loss, tissue damage and poor healing of the surrounding tissue, limited access to the target brain region, and, importantly, unreliable fixation points for holding the mouse's head.
  
  
  METHODS
  We describe an optimized surgical procedure that ensures limited tissue damage and delineate a method for implanting head plates to hold the animal firmly in place.
  
  
  RESULTS
  Using the cerebellum as a model, we implement an extracellular recording technique to acquire single units from Purkinje cells and cerebellar nuclear neurons in behaving mice. We validate the stability of our method by holding single units after injecting the powerful tremorgenic drug harmaline. We performed multiple structural analyses after recording.
  
  
  METHODS
  Our approach is ideal for studying neuronal function in active mice and valuable for recording single-neuron activity when considerable motion is unavoidable.
  
  
  CONCLUSIONS
  The surgical principles we present for accessing the cerebellum can be easily adapted to examine the function of neurons in other brain regions.
authors.affiliation: Department of Pathology and Immunology, Department of Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA.
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: White
authors.affiliation: Department of Pathology and Immunology, Department of Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Lin
authors.affiliation: Department of Pathology and Immunology, Department of Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA.
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Brown
authors.affiliation: Department of Pathology and Immunology, Department of Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA.
authors.forename: Marife
authors.initials: M
authors.lastname: Arancillo
authors.affiliation: Department of Pathology and Immunology, Department of Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA.
authors.forename: Elizabeth P
authors.initials: EP
authors.lastname: Lackey
authors.affiliation: Department of Pathology and Immunology, Department of Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA.
authors.forename: Trace L
authors.initials: TL
authors.lastname: Stay
authors.affiliation: Department of Pathology and Immunology, Department of Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA. Electronic address: sillitoe@bcm.edu.
authors.forename: Roy V
authors.initials: RV
authors.lastname: Sillitoe
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D014408:Biomarkers, Tumor / Q000378:metabolism; D002531:Cerebellum / Q000166:cytology* / Q000196:embryology / Q000254:growth & development; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods; D004622:Embryo, Mammalian; D006360:Heat-Shock Proteins / Q000378:metabolism; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018832:Molecular Chaperones; D009363:Neoplasm Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000502:physiology*; D011963:Receptors, GABA-A / Q000378:metabolism; D059629:Signal-To-Noise Ratio; D014851:Wakefulness / Q000502:physiology*; D002256:Carbonic Anhydrases
chemical_list: D014408:Biomarkers, Tumor; D006360:Heat-Shock Proteins; D053496:Inositol 1,4,5-Trisphosphate Receptors; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D011963:Receptors, GABA-A; C512821:Car8 protein, mouse; D002256:Carbonic Anhydrases; C486113:Hsbp1 protein, mouse
keywords: Action potential; Behavior; Cerebellum; Electrophysiology; Surgery; Tremor