title: Energy demand of synaptic transmission at the hippocampal Schaffer-collateral synapse.
abstract: Neuroenergetic models of synaptic transmission predicted that energy demand is highest for action potentials (APs) and postsynaptic ion fluxes, whereas the presynaptic contribution is rather small. Here, we addressed the question of energy consumption at Schaffer-collateral synapses. We monitored stimulus-induced changes in extracellular potassium, sodium, and calcium concentration while recording partial oxygen pressure (pO(2)) and NAD(P)H fluorescence. Blockade of postsynaptic receptors reduced ion fluxes as well as pO(2) and NAD(P)H transients by ∼50%. Additional blockade of transmitter release further reduced Na(+), K(+), and pO(2) transients by ∼30% without altering presynaptic APs, indicating considerable contribution of Ca(2+)-removal, transmitter and vesicle turnover to energy consumption.
authors.affiliation: Institute for Neurophysiology, Charité-Universitätsmedizin, Berlin, Germany.
authors.forename: Agustin
authors.initials: A
authors.lastname: Liotta
authors.forename: Jörg
authors.initials: J
authors.lastname: Rösner
authors.forename: Christine
authors.initials: C
authors.lastname: Huchzermeyer
authors.forename: Anna
authors.initials: A
authors.lastname: Wojtowicz
authors.forename: Oliver
authors.initials: O
authors.lastname: Kann
authors.forename: Dietmar
authors.initials: D
authors.lastname: Schmitz
authors.forename: Uwe
authors.initials: U
authors.lastname: Heinemann
authors.forename: Richard
authors.initials: R
authors.lastname: Kovács
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D056547:CA1 Region, Hippocampal / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology*; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D005971:Glutamates / Q000502:physiology; D006624:Hippocampus / Q000378:metabolism* / Q000502:physiology*; D066298:In Vitro Techniques; D015640:Ion Channel Gating / Q000502:physiology; D007700:Kinetics; D008297:Male; D009249:NADP / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology; D011188:Potassium / Q000378:metabolism; D017966:Pyramidal Cells / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000378:metabolism; D013569:Synapses / Q000378:metabolism* / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000502:physiology
chemical_list: D015220:Calcium Channels; D005971:Glutamates; D009249:NADP; D005680:gamma-Aminobutyric Acid; D012964:Sodium; D011188:Potassium; D002118:Calcium