Circuit mechanisms of associative fear learning in auditory cortex

Munich Psychiatry Lecture Series | MPLS

  • Cancelled/Abgesagt
  • Datum: 08.11.2016
  • Uhrzeit: 15:00 - 16:00
  • Vortragende(r): Johannes J. Letzkus, PhD
  • Research Group Leader, Max Planck Institute for Brain Research, Frankfurt
  • Ort: Max-Planck-Institut für Psychiatrie
  • Raum: Hörsaal
  • Gastgeber: Alessio Attardo
  • Kontakt: junkert@psych.mpg.de
Circuit mechanisms of associative fear learning in auditory cortex
The neuronal mechanisms of associative learning have been under intense investigation for many decades. While synaptic plasticity as the putative cellular mechanism of learning has been studied in great detail, we know much less about the interactions of different types of neurons in the local network that lead to memory formation. In particular, all aspects of circuit function are tightly controlled by different types of inhibitory interneurons, but their role in learning is little understood.

The neuronal mechanisms of associative learning have been under intense investigation for many decades. While synaptic plasticity as the putative cellular mechanism of learning has been studied in great detail, we know much less about the interactions of different types of neurons in the local network that lead to memory formation. In particular, all aspects of circuit function are tightly controlled by different types of inhibitory interneurons, but their role in learning is little understood. To address this question, we record activity in identified neurons in auditory cortex during formation of an associative auditory fear memory. Our results indicate that a mild foot-shock, which drives learning in this paradigm, elicits strong and differential responses in different types of auditory cortex interneurons, leading to disinhibition of pyramidal neurons. Optogenetic manipulations counteracting the observed disinhibition of pyramidal cells exclusively during the foot-shock strongly reduce fear memory acquisition, directly demonstrating causality between circuit events in auditory cortex and learning at the behavioral level. Importantly, recent experiments suggest that disinhibition during the foot-shock is also a crucial mechanism for fear learning in the amygdala. Together with other recent work, our results highlight the importance of interneuron-interneuron interactions for memory formation and suggest that disinhibition is a key circuit mechanism for induction of experience-dependent plasticity during associative learning.

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