title: Mesoscopic patterns of neural activity support songbird cortical sequences.
abstract: Time-locked sequences of neural activity can be found throughout the vertebrate forebrain in various species and behavioral contexts. From "time cells" in the hippocampus of rodents to cortical activity controlling movement, temporal sequence generation is integral to many forms of learned behavior. However, the mechanisms underlying sequence generation are not well known. Here, we describe a spatial and temporal organization of the songbird premotor cortical microcircuit that supports sparse sequences of neural activity. Multi-channel electrophysiology and calcium imaging reveal that neural activity in premotor cortex is correlated with a length scale of 100 µm. Within this length scale, basal-ganglia-projecting excitatory neurons, on average, fire at a specific phase of a local 30 Hz network rhythm. These results show that premotor cortical activity is inhomogeneous in time and space, and that a mesoscopic dynamical pattern underlies the generation of the neural sequences controlling song.
authors.affiliation: Department of Cognitive and Neural Systems, Boston University, Boston, Massachusetts, United States of America; Department of Biology, Boston University, Boston, Massachusetts, United States of America.
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Markowitz
authors.affiliation: Department of Biology, Boston University, Boston, Massachusetts, United States of America.
authors.forename: William A
authors.initials: WA
authors.lastname: Liberti
authors.affiliation: Program in Neuroscience, Harvard University, Boston, Massachusetts, United States of America.
authors.forename: Grigori
authors.initials: G
authors.lastname: Guitchounts
authors.affiliation: Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.
authors.forename: Tarciso
authors.initials: T
authors.lastname: Velho
authors.affiliation: Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.
authors.forename: Carlos
authors.initials: C
authors.lastname: Lois
authors.affiliation: Department of Biology, Boston University, Boston, Massachusetts, United States of America; Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Gardner
mesh_terms: D000818:Animals; D046369:Finches / Q000502:physiology*; D008297:Male; D009044:Motor Cortex / Q000033:anatomy & histology / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D014828:Vocalization, Animal / Q000502:physiology*