title: Examining the limits of cellular adaptation bursting mechanisms in biologically-based excitatory networks of the hippocampus.
abstract: Determining the biological details and mechanisms that are essential for the generation of population rhythms in the mammalian brain is a challenging problem. This problem cannot be addressed either by experimental or computational studies in isolation. Here we show that computational models that are carefully linked with experiment provide insight into this problem. Using the experimental context of a whole hippocampus preparation in vitro that spontaneously expresses theta frequency (3-12 Hz) population bursts in the CA1 region, we create excitatory network models to examine whether cellular adaptation bursting mechanisms could critically contribute to the generation of this rhythm. We use biologically-based cellular models of CA1 pyramidal cells and network sizes and connectivities that correspond to the experimental context. By expanding our mean field analyses to networks with heterogeneity and non all-to-all coupling, we allow closer correspondence with experiment, and use these analyses to greatly extend the range of parameter values that are explored. We find that our model excitatory networks can produce theta frequency population bursts in a robust fashion.Thus, even though our networks are limited by not including inhibition at present, our results indicate that cellular adaptation in pyramidal cells could be an important aspect for the occurrence of theta frequency population bursting in the hippocampus. These models serve as a starting framework for the inclusion of inhibitory cells and for the consideration of additional experimental features not captured in our present network models.
authors.affiliation: Fundamental Neurobiology, Toronto Western Research Institute (TWRI), University Health Network (UHN), Krembil Discovery Tower (KDT), 60 Leonard Ave. 7KD411, Toronto, Ontario, M5T 2S8, Canada.|Department of Physiology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: K A
authors.initials: KA
authors.lastname: Ferguson
authors.affiliation: Fundamental Neurobiology, Toronto Western Research Institute (TWRI), University Health Network (UHN), Krembil Discovery Tower (KDT), 60 Leonard Ave. 7KD411, Toronto, Ontario, M5T 2S8, Canada.|Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
authors.forename: F
authors.initials: F
authors.lastname: Njap
authors.affiliation: Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
authors.forename: W
authors.initials: W
authors.lastname: Nicola
authors.affiliation: Fundamental Neurobiology, Toronto Western Research Institute (TWRI), University Health Network (UHN), Krembil Discovery Tower (KDT), 60 Leonard Ave. 7KD411, Toronto, Ontario, M5T 2S8, Canada. frances.skinner@gmail.com.|Departments of Medicine (Neurology) and Physiology, University of Toronto, Toronto, Ontario, Canada. frances.skinner@gmail.com.
authors.forename: F K
authors.initials: FK
authors.lastname: Skinner
authors.affiliation: Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada. sacampbell@uwaterloo.ca.
authors.forename: S A
authors.initials: SA
authors.lastname: Campbell
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D056547:CA1 Region, Hippocampal / Q000502:physiology*; D003198:Computer Simulation; D055641:Mathematical Concepts; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology*; D016571:Neural Networks, Computer; D017966:Pyramidal Cells / Q000502:physiology; D051381:Rats; D013826:Theta Rhythm / Q000502:physiology*
keywords: Computer simulation; Mathematical model; Mean-field theory; Network model; Theta rhythm