RT Journal Article
SR Electronic
T1 Neuronal FOS reports synchronized activity of presynaptic neurons
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2023.09.04.556168
DO 10.1101/2023.09.04.556168
A1 Margarita Anisimova
A1 Paul J. Lamothe-Molina
A1 Andreas Franzelin
A1 Aman S. Aberra
A1 Michael B. Hoppa
A1 Christine E. Gee
A1 Thomas G. Oertner
YR 2023
UL http://biorxiv.org/content/early/2023/09/05/2023.09.04.556168.abstract
AB The immediate early gene FOS is frequently used as a marker for highly active neurons. Implicit in this use is the assumption that there is a correlation between neuronal spiking and FOS expression. Here we use optogenetic stimulation of hippocampal neurons to investigate the relation between spike frequency and FOS expression, and report several surprising observations. First, FOS expression is cell-type specific, spiking CA2 pyramidal neurons rarely express FOS. Second, FOS has a U-shaped dependence on frequency: Spiking at 0.1 Hz is more effective than high frequency spiking (50 Hz) while intermediate frequencies do not induce FOS. Third, the pathway from spiking to FOS is not cell-autonomous. Instead, transmitter release and metabotropic glutamate receptor (mGluR) activation are required and, at 0.1 Hz, FOS is induced independently of CREB/calcineurin/MEK pathways. We propose that FOS does not primarily encode a neuron’s own spike frequency but indicates repeated participation in highly synchronized activity, e.g. sharp wave ripples.Competing Interest StatementThe authors have declared no competing interest.