UC San Diego UC San Diego Electronic Theses and Dissertations Title Inhibition, recurrent excitation, and neural feedback in computational models of sparse bursting and birdsong sequencing Permalink https://escholarship.org/uc/item/2nm5d3tj Author Gibb, Leif Publication Date 2009 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA, SAN DIEGO Inhibition, Recurrent Excitation, and Neural Feedback in Computational Models of Sparse Bursting and Birdsong Sequencing A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Neurosciences with a Specialization in Computational Neurobiology by Leif Gibb Committee in charge: Henry D. I. Abarbanel, Chair Maxim Bazhenov Gert Cauwenberghs Timothy Q. Gentner William B. Kristan Terrence J. Sejnowski 2009 Copyright Leif Gibb, 2009 All rights reserved. Signature Page The Dissertation of Leif Gibb is approved, and it is acceptable in quality and form for publication on microfilm and electronically: Chair University of California, San Diego 2009 iii DEDICATION To my mother, Roberta Gibb, who has always been my greatest source of love, support, and inspiration; my grandmother, Jean Gibb, who helped her raise me and wanted to live to see me earn my PhD; and my grandfather, Prof. Thomas R. P. Gibb, who helped inspire my love of science. iv TABLE OF CONTENTS Signature Page ............................................................................................................... iii Dedication ...................................................................................................................... iv Table of Contents ........................................................................................................... v List of Tables ............................................................................................................... viii List of Figures ................................................................................................................ ix Acknowledgements ....................................................................................................... xi Curriculum Vitae ......................................................................................................... xiv Abstract of the Dissertation ......................................................................................... xix Chapter 1: Inhibition and Recurrent Excitation in a Computational Model of Sparse Bursting in Song Nucleus HVC ..................................................................................... 1 Abstract ............................................................................................................... 1 Introduction ........................................................................................................ 2 Methods .............................................................................................................. 4 Basic spiking model ............................................................................... 4 Modeling HVC RA neurons ...................................................................... 6 Modeling HVC I neurons ......................................................................... 8 Modeling synaptic currents .................................................................. 10 Modeling temperature dependence of neurons and synapses ............... 11 Synapses of physiological strength ...................................................... 12 Poisson synapses .................................................................................. 13 Sparseness index and spike time .......................................................... 14 Results .............................................................................................................. 14 Initial model: Dynamical behavior of a single bistable cluster ............ 14 Mechanisms of inhibition ..................................................................... 19 A model of HVC RA sparse bursting: the limitations of local inhibition ............................................................................................... 25 A model of HVC RA sparse bursting utilizing global inhibition ............ 28 Sparse bursting without clusters or unidirectional HVC RA chains ....... 36 Experimental predictions of the sparse bursting model ....................... 37 Discussion ......................................................................................................... 42 Which type of HVC RA neuron exhibits sparse premotor bursting? ...... 47 2+ Potential role for a Ca current in HVC RA bursting ............................ 47 Cluster size ........................................................................................... 48 A possible role for developmental plasticity in the establishment of HVC I →→→ HVC RA connectivity .............................................................. 49 Acknowledgements .......................................................................................... 51 Grants ............................................................................................................... 52 v References ........................................................................................................ 52 Supplementary Methods ................................................................................... 58 Supplementary Results ..................................................................................... 61 Chapter 2: Inhibition and Neural Feedback in a Computational Model of Birdsong Sequencing ................................................................................................................... 66 Abstract ............................................................................................................. 66 Introduction ...................................................................................................... 67 Methods ............................................................................................................ 74 Basic spiking model ............................................................................. 74 Modeling HVC RA neurons .................................................................... 75 Modeling HVC I neurons ....................................................................... 76 Modeling other neurons (RA, DM/PAm, Uva, RAm, nXIIts) ............. 77 Modeling synaptic currents .................................................................. 77 Modeling temperature dependence of neurons and synapses ............... 78 Spike time ............................................................................................. 79 Analysis of stimulation results ............................................................. 79 Statistics ................................................................................................ 80 Results .............................................................................................................. 80 Brainstem feedback in a model of syllable sequencing ........................ 80 Variations on and perturbations of the syllable sequencing model ...... 89 The effects of stimulation on model behavior ...................................... 93 Timing dependence of stimulation effects ......................................... 104 Feedback delay and HVC cooling ...................................................... 106 Discussion ....................................................................................................... 113 Absence of syllable transitions in experimental data ......................... 118 Empirical influence of Uva on HVC .................................................. 121 Which brainstem nucleus (if any) is involved in syllable sequencing? ........................................................................................ 122 Thalamic gating and interruption of song at syllable boundaries ....... 123 Acknowledgements ........................................................................................ 124 Grants ............................................................................................................. 125 References ...................................................................................................... 125 Supplementary Figures ................................................................................... 132 Appendix .................................................................................................................... 135 Chapter 1 ........................................................................................................ 135 Extended summary of HVC neuron types .......................................... 135 Roles of other neurons and synaptic connections in the HVC microcircuit ......................................................................................... 137 Anatomical clusters in HVC ............................................................... 140 Chapter 2 ........................................................................................................ 140 Extended summary of inputs and feedback pathways to HVC .......... 140 Extended summary of birdsong sequence variability ......................... 141 vi Extended discussion of the nature and function of bilateral input to HVC ...................................................................................................