title: Interneuron Deficit Associates Attenuated Network Synchronization to Mismatch of Energy Supply and Demand in Aging Mouse Brains.
abstract: Higher cognitive functions depend critically on synchronized network activity in the gamma range (30-100 Hz), which results from activity of fast-spiking parvalbumin-positive (PV) interneurons. Here, we examined synaptic activity in the gamma band in relation to PV interneuron activity, stimulation-induced calcium activity in neurons and astrocytes, and cerebral blood flow and oxygen responses in the somatosensory cortex of young adult and old adult mice in vivo using electrical whisker pad stimulation. Gamma activity was reduced in old adult mice, and associated with reduced calcium activity of PV interneurons, whereas the overall responses of neurons and astrocytes were unchanged. Hemodynamic responses were highly correlated to the power of synaptic activity in both young adult and old adult mice, but the hemodynamic response amplitude attained was lower in old adult mice. In comparison, the work-dependent rise in O2 use, that is, the rise in the cerebral metabolic rate of oxygen (CMRO2) evoked by excitatory postsynaptic currents almost doubled in old adult mice. We conclude that PV interneuron function and gamma activity are particularly affected in old adult mice. Alterations in neurovascular coupling and CMRO2 responses may contribute to increased frailty and risk of cognitive decline in aged brains.
authors.affiliation: Department of Neuroscience and Pharmacology.|Center for Healthy Aging, University of Copenhagen, Copenhagen N 2200, Denmark.
authors.forename: Sanne Barsballe
authors.initials: SB
authors.lastname: Jessen
authors.affiliation: Department of Neuroscience and Pharmacology.|Center for Healthy Aging, University of Copenhagen, Copenhagen N 2200, Denmark.
authors.forename: Claus
authors.initials: C
authors.lastname: Mathiesen
authors.affiliation: Department of Neuroscience and Pharmacology.
authors.forename: Barbara Lykke
authors.initials: BL
authors.lastname: Lind
authors.affiliation: Department of Neuroscience and Pharmacology.|Center for Healthy Aging, University of Copenhagen, Copenhagen N 2200, Denmark.|Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup 2600, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: Lauritzen
mesh_terms: D000200:Action Potentials; D000375:Aging / Q000502:physiology*; D000818:Animals; D001253:Astrocytes / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000502:physiology; D019706:Excitatory Postsynaptic Potentials; D005260:Female; D065818:Gamma Rhythm / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007395:Interneurons / Q000502:physiology*; D008297:Male; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010100:Oxygen / Q000097:blood; D010320:Parvalbumins / Q000378:metabolism; D013003:Somatosensory Cortex / Q000502:physiology*; D013826:Theta Rhythm / Q000502:physiology*; D055698:Touch Perception / Q000502:physiology; D014738:Vibrissae / Q000502:physiology
chemical_list: D010320:Parvalbumins; D049452:Green Fluorescent Proteins; D010100:Oxygen; D002118:Calcium
keywords: aging; energy metabolism; gamma frequency activity; neurovascular coupling; parvalbumin-positive interneurons