MBExC /CIDBN Lecture

Professor Ilya A. Fleidervish, M.D., Ph.D. from the Ben-Gurion University, Beersheva, Israel will talk about “Mitochondria decode neuronal firing frequency and Hebbian coincidences” during the MBExC Lecture on June 20th, 2023 at 1:15 pm at the small lecture hall (behind the library) at the Max Planck Institute for Multidisciplinary Sciences, Hermann-Rein-Str. 3.

Abstract
Mitochondrial metabolism is critical for brain function. However, the mechanisms linking mitochondrial energy production to neuronal activity are elusive. Using whole-cell electrical recordings from Layer 5 pyramidal neurons in cortical slices and fluorescence imaging of cytosolic, mitochondrial Ca²⁺ indicators and endogenous NAD(P)H, we revealed ultra-fast, spike-evoked mitochondrial Ca²⁺ transients temporally similar to cytosolic Ca²⁺ elevations. We demonstrate that, whereas single or few spikes elicit the mitochondrial Ca²⁺ transients throughout the cell, their amplitude is differentially regulated in distinct neuronal compartments. Thus, these signals were prominent in the soma and apical dendrites and ~3 times smaller in basal dendrites and axons.  The spike firing frequency had a subtle effect on the amplitude of the cytosolic Ca²⁺ elevations but dramatically affected mitochondrial Ca²⁺ transients and NAD(P)H oxidation and recovery rates. Moreover, while subthreshold EPSPs alone caused no detectable Ca²⁺ elevation in dendritic mitochondria, the Hebbian coincidence of unitary EPSP and postsynaptic spike produced a localized, single mitochondrial Ca²⁺ elevation. These findings suggest that neuronal mitochondria are uniquely capable of decoding firing frequency and EPSP-to-spike time intervals for tuning the metabolic rate and triggering changes in synaptic efficacy.

Host: Prof. Dr. Fred Wolf, MPI-DS and University of Göttingen

Please find the poster of the announcement here: