title: Visually evoked activity in cortical cells imaged in freely moving animals.
abstract: We describe a miniaturized head-mounted multiphoton microscope and its use for recording Ca(2+) transients from the somata of layer 2/3 neurons in the visual cortex of awake, freely moving rats. Images contained up to 20 neurons and were stable enough to record continuously for >5 min per trial and 20 trials per imaging session, even as the animal was running at velocities of up to 0.6 m/s. Neuronal Ca(2+) transients were readily detected, and responses to various static visual stimuli were observed during free movement on a running track. Neuronal activity was sparse and increased when the animal swept its gaze across a visual stimulus. Neurons showing preferential activation by specific stimuli were observed in freely moving animals. These results demonstrate that the multiphoton fiberscope is suitable for functional imaging in awake and freely moving animals.
authors.affiliation: Network Imaging Group, Max Planck Institute for Biological Cybernetics, Spemannstrasse 41, 72076 Tübingen, Germany.
authors.forename: Juergen
authors.initials: J
authors.lastname: Sawinski
authors.forename: Damian J
authors.initials: DJ
authors.lastname: Wallace
authors.forename: David S
authors.initials: DS
authors.lastname: Greenberg
authors.forename: Silvie
authors.initials: S
authors.lastname: Grossmann
authors.forename: Winfried
authors.initials: W
authors.lastname: Denk
authors.forename: Jason N D
authors.initials: JN
authors.lastname: Kerr
mesh_terms: D000818:Animals; D002118:Calcium / Q000502:physiology*; D005074:Evoked Potentials, Visual; D008297:Male; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods; D009068:Movement; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D014793:Visual Cortex / Q000166:cytology / Q000502:physiology*
chemical_list: D002118:Calcium