title: Development and modulation of intrinsic membrane properties control the temporal precision of auditory brain stem neurons.
abstract: Passive and active membrane properties determine the voltage responses of neurons. Within the auditory brain stem, refinements in these intrinsic properties during late postnatal development usually generate short integration times and precise action-potential generation. This developmentally acquired temporal precision is crucial for auditory signal processing. How the interactions of these intrinsic properties develop in concert to enable auditory neurons to transfer information with high temporal precision has not yet been elucidated in detail. Here, we show how the developmental interaction of intrinsic membrane parameters generates high firing precision. We performed in vitro recordings from neurons of postnatal days 9-28 in the ventral nucleus of the lateral lemniscus of Mongolian gerbils, an auditory brain stem structure that converts excitatory to inhibitory information with high temporal precision. During this developmental period, the input resistance and capacitance decrease, and action potentials acquire faster kinetics and enhanced precision. Depending on the stimulation time course, the input resistance and capacitance contribute differentially to action-potential thresholds. The decrease in input resistance, however, is sufficient to explain the enhanced action-potential precision. Alterations in passive membrane properties also interact with a developmental change in potassium currents to generate the emergence of the mature firing pattern, characteristic of coincidence-detector neurons. Cholinergic receptor-mediated depolarizations further modulate this intrinsic excitability profile by eliciting changes in the threshold and firing pattern, irrespective of the developmental stage. Thus our findings reveal how intrinsic membrane properties interact developmentally to promote temporally precise information processing.
authors.affiliation: Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany; Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany; and.
authors.forename: Delwen L
authors.initials: DL
authors.lastname: Franzen
authors.affiliation: Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany; Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany; and.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Gleiss
authors.affiliation: Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany;
authors.forename: Christina
authors.initials: C
authors.lastname: Berger
authors.affiliation: Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany;
authors.forename: Franziska S
authors.initials: FS
authors.lastname: Kümpfbeck
authors.affiliation: Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany; Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany; and.
authors.forename: Julian J
authors.initials: JJ
authors.lastname: Ammer
authors.affiliation: Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany; BioImaging Center, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany felmy@zi.biologie.uni-muenchen.de.
authors.forename: Felix
authors.initials: F
authors.lastname: Felmy
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D001306:Auditory Pathways / Q000254:growth & development* / Q000502:physiology*; D001933:Brain Stem / Q000254:growth & development* / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology*; D017097:Electric Impedance; D005849:Gerbillinae; D007150:Immunohistochemistry; D007700:Kinetics; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism; D013997:Time Factors; D046509:Tissue Culture Techniques
chemical_list: D011188:Potassium
keywords: cholinergic modulation; neuronal excitability; postnatal development; ventral nucleus of the lateral lemniscus