title: Brain-derived neurotrophic factor differentially modulates excitability of two classes of hippocampal output neurons.
abstract: Brain-derived neurotrophic factor (BDNF) plays an important role in hippocampus-dependent learning and memory. Canonically, this has been ascribed to an enhancing effect on neuronal excitability and synaptic plasticity in the CA1 region. However, it is the pyramidal neurons in the subiculum that form the primary efferent pathways conveying hippocampal information to other areas of the brain, and yet the effect of BDNF on these neurons has remained unexplored. We present new data that BDNF regulates neuronal excitability and cellular plasticity in a much more complex manner than previously suggested. Subicular pyramidal neurons can be divided into two major classes, which have different electrophysiological and morphological properties, different requirements for the induction of plasticity, and different extrahippocampal projections. We found that BDNF increases excitability in one class of subicular pyramidal neurons yet decreases excitability in the other class. Furthermore, while endogenous BDNF was necessary for the induction of synaptic plasticity in both cell types, BDNF enhanced intrinsic plasticity in one class of pyramidal neurons yet suppressed intrinsic plasticity in the other. Taken together, these data suggest a novel role for BDNF signaling, as it appears to dynamically and bidirectionally regulate the output of hippocampal information to different regions of the brain.
authors.affiliation: Department of Neurobiology, Northwestern University, Evanston, Illinois; Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, Virginia;
authors.forename: A R
authors.initials: AR
authors.lastname: Graves
authors.affiliation: Department of Neurobiology, Northwestern University, Evanston, Illinois; Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan;
authors.forename: S J
authors.initials: SJ
authors.lastname: Moore
authors.affiliation: Department of Neurobiology, Northwestern University, Evanston, Illinois; Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, Virginia;
authors.forename: N
authors.initials: N
authors.lastname: Spruston
authors.affiliation: Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Pediatrics, The University of Chicago, Chicago, Illinois; and.
authors.forename: A K
authors.initials: AK
authors.lastname: Tryba
authors.affiliation: Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, Tennessee ckaczoro@uthsc.edu.
authors.forename: C C
authors.initials: CC
authors.lastname: Kaczorowski
mesh_terms: D000200:Action Potentials / Q000187:drug effects*; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D006624:Hippocampus / Q000166:cytology*; D008297:Male; D051379:Mice; D009474:Neurons / Q000145:classification* / Q000187:drug effects*; D018408:Patch-Clamp Techniques
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D018691:Excitatory Amino Acid Antagonists
keywords: burst firing; hippocampus; intrinsic plasticity; long-term potentiation; metabotropic glutamate receptors