title: Targeted pruning of a neuron's dendritic tree via femtosecond laser dendrotomy.
abstract: Neurons are classified according to action potential firing in response to current injection. While such firing patterns are shaped by the composition and distribution of ion channels, modelling studies suggest that the geometry of dendritic branches also influences temporal firing patterns. Verifying this link is crucial to understanding how neurons transform their inputs to output but has so far been technically challenging. Here, we investigate branching-dependent firing by pruning the dendritic tree of pyramidal neurons. We use a focused ultrafast laser to achieve highly localized and minimally invasive cutting of dendrites, thus keeping the rest of the dendritic tree intact and the neuron functional. We verify successful dendrotomy via two-photon uncaging of neurotransmitters before and after dendrotomy at sites around the cut region and via biocytin staining. Our results show that significantly altering the dendritic arborisation, such as by severing the apical trunk, enhances excitability in layer V cortical pyramidal neurons as predicted by simulations. This method may be applied to the analysis of specific relationships between dendritic structure and neuronal function. The capacity to dynamically manipulate dendritic topology or isolate inputs from various dendritic domains can provide a fresh perspective on the roles they play in shaping neuronal output.
authors.affiliation: Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia.
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Go
authors.affiliation: Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia.
authors.forename: Julian Min Chiang
authors.initials: JM
authors.lastname: Choy
authors.affiliation: Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia.
authors.forename: Alexandru Serban
authors.initials: AS
authors.lastname: Colibaba
authors.affiliation: Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Redman
authors.affiliation: Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Canberra, ACT, Australia.
authors.forename: Hans-A
authors.initials: HA
authors.lastname: Bachor
authors.affiliation: Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia.|Medical School, College of Medicine, Biology and Environment, The Australian National University, Canberra, ACT, Australia.
authors.forename: Christian
authors.initials: C
authors.lastname: Stricker
authors.affiliation: Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia.
authors.forename: Vincent Ricardo
authors.initials: VR
authors.lastname: Daria
mesh_terms: D000200:Action Potentials; D000818:Animals; D003712:Dendrites; D007834:Lasers; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods; D009474:Neurons / Q000166:cytology* / Q000502:physiology*; D017966:Pyramidal Cells / Q000166:cytology / Q000502:physiology; D051381:Rats