Inhibition enhances memory capacity: optimal feedback, transient replay and oscillations.
Recurring sequences of neuronal activation in the hippocampus are a candidate for a neurophysiological correlate of episodic memory. Here, we discuss a mean-field theory for such spike sequences in phase space and show how they become unstable when the neuronal network operates at maximum memory capacity. We find that inhibitory feedback rescues replay of the sequences, giving rise to oscillations and thereby enhancing the network's capacity. We further argue that transient sequences in an overloaded network with feedback inhibition may provide a mechanistic picture of memory-related neuronal activity during hippocampal sharp-wave ripple complexes.
Department Biologie II, Ludwig-Maximilians University Munich, Großhadernerstrasse 2, 82152 Planegg, Germany. kammerer@bio.lmu.de
Axel
A
Kammerer
Alvaro
A
Tejero-Cantero
Christian
C
Leibold
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001683:Biological Clocks / Q000502:physiology*; D025461:Feedback, Physiological / Q000502:physiology*; D006624:Hippocampus / Q000166:cytology; D006801:Humans; D008568:Memory / Q000502:physiology*; D008959:Models, Neurological; D009433:Neural Inhibition / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D017711:Nonlinear Dynamics