title: Characterization of intrinsic properties of cingulate pyramidal neurons in adult mice after nerve injury.
abstract: The anterior cingulate cortex (ACC) is important for cognitive and sensory functions including memory and chronic pain. Glutamatergic excitatory synaptic transmission undergo long-term potentiation in ACC pyramidal cells after peripheral injury. Less information is available for the possible long-term changes in neuronal action potentials or intrinsic properties. In the present study, we characterized cingulate pyramidal cells in the layer II/III of the ACC in adult mice. We then examined possible long-term changes in intrinsic properties of the ACC pyramidal cells after peripheral nerve injury. In the control mice, we found that there are three major types of pyramidal cells according to their action potential firing pattern: (i) regular spiking (RS) cells (24.7%), intrinsic bursting (IB) cells (30.9%), and intermediate (IM) cells (44.4%). In a state of neuropathic pain, the population distribution (RS: 21.3%; IB: 31.2%; IM: 47.5%) and the single action potential properties of these three groups were indistinguishable from those in control mice. However, for repetitive action potentials, IM cells from neuropathic pain animals showed higher initial firing frequency with no change for the properties of RS and IB neurons from neuropathic pain mice. The present results provide the first evidence that, in addition to synaptic potentiation reported previously, peripheral nerve injury produces long-term plastic changes in the action potentials of cingulate pyramidal neurons in a cell type-specific manner.
authors.affiliation: Department of Physiology, Faculty of Medicine, University of Toronto, Medical Science Building, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada. xiaoyan.cao@utoronto.ca
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Cao
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.forename: Long-Jun
authors.initials: LJ
authors.lastname: Wu
authors.forename: Xiang-Yao
authors.initials: XY
authors.lastname: Li
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.forename: Min
authors.initials: M
authors.lastname: Zhuo
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D003071:Cognition / Q000502:physiology; D004195:Disease Models, Animal; D004644:Emotions / Q000502:physiology; D006179:Gyrus Cinguli / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009437:Neuralgia / Q000503:physiopathology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009619:Nociceptors / Q000502:physiology; D009924:Organ Culture Techniques; D018408:Patch-Clamp Techniques; D010523:Peripheral Nervous System Diseases / Q000503:physiopathology*; D017966:Pyramidal Cells / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology; D013995:Time