WEBINAR - BMI Progress Reports 2020 // Prof. Schneggenburger's Lab: Michael Kintscher - Tail striatum contributes to the control of learned fear expression
Event details
Date | 17.06.2020 |
Hour | 13:15 › 14:00 |
Speaker | Michael Kintscher |
Category | Conferences - Seminars |
During fear learning, an initially innocuous sensory cue acquires a negative emotional value, and can thereby induce a defensive behavior, like immobility or freezing. An amygdala - midbrain pathway is known to play a role in the execution of learned fear behaviors, but it is likely that other motor-related areas are involved in the execution of such a strong behavior. Here, we study the role of the ventral tail striatum, a brain area adjacent to the amygdala, in auditory-cued fear learning in mice. Using rabies-virus mediated tracing, we find that the secondary sensory cortex and the underlying posterior insular cortex are the most prevalent input regions of the ventral tail striatum. Optogenetic circuit mapping shows that the posterior insular cortex provides strong excitatory drive of both D1-receptor-positive and of Adora-positive medial spiny neurons (MSNs). Preliminary results suggest that following fear learning, excitatory synapses from pInsCx onto D1-MSNs undergo LTP, whereas those onto Adora-MSNs undergo LTD. Using fiber photometry of Ca2+ transients, we find that D1- and Adora- MSNs are strongly activated by an aversive stimulus (foot shock). Silencing the foot shock-driven activity in each neuron population, we found that foot shock-driven activity of D1-MSNs causes an enhanced learned freezing response to tones one day later, whereas Adora-MSNs cause a learned suppression of freezing at times when no tones are given during the retrieval day. Thus, opposite forms of learning in the two populations of MSNs enhances the freezing response driven by the sensory cue. Our study defines a role for a striatal structure in the control of learned fear behavior, a finding that should be relevant for the treatment of psychiatric pathologies like anxiety disorders.
Practical information
- Informed public
- Free
Organizer
- Brain Mind institute