Extended Data Fig. 12: ITC to CeM connectivity.
From: Intercalated amygdala clusters orchestrate a switch in fear state
a, Schematic illustrating the experimental design used to assess connectivity between ITCdm or ITCvm neurons and CeM neurons. To isolate IPSCs, CPP (10 μM) and CNQX (10 μM) were applied. b, Example voltage-clamp recording from a CeM neuron showing selective IPSC elicited by stimulation of the ITCvm but not ITCdm. c, Summary of connectivity from ITCdm and ITCvm to CeM (n = 11 neurons from 4 mice). *P = 7.5 × 10−3, Fisher’s exact test. d, Evoked IPSC amplitudes recorded from CeM neurons (at −70 mV holding potential) in response to stimulation of ITCdm or ITCvm clusters. e, Synaptic conductance calculated based on IPSC amplitudes recorded at three different holding potentials (−60, −70, and −80 mV). f, Example injections of CTB555 targeted to the ventrolateral periaqueductal grey (vlPAG). Scale bar, 200 μm. g, Schematic illustrating the experimental design used to assess connectivity between ITCdm or ITCvm neurons and CeM neurons projecting to the vlPAG. vlPAG-projecting CeM neurons were retrogradely labelled with CTB injections into the vlPAG. Whole-cell recordings were performed in CTB+ CeM neurons while photostimulating incoming axons expressing ChR2–EYFP from either ITCdm or ITCvm. h, Summary of connectivity from ITCdm and ITCvm to vlPAG-projecting CeM neurons (n = 15 neurons from 4 mice and n = 10 neurons from 4 mice). *P = 0.0001, Fisher’s exact test. i, Evoked IPSC amplitudes recorded from CTB+ CeM neurons (at 0 mV holding potential) in response to stimulation of axons from ITCdm or ITCvm. j, Example injections of CTB555 and CTB647 targeted to the PL or IL, respectively. Scale bar, 500 μm. k, Example BLA histology showing PLp and ILp BLA neurons. Both subpopulations are located in the medial part of the BLA. Scale bar, 200 μm. l, Mostly non-overlapping PLp and ILp subpopulations; orange arrow indicates an example of a double-labelled neuron. Scale bar, 50 μm. m, Quantification of double-labelled neurons (n = 3 mice). Mean ± s.e.m. n, State-dependent functional changes in amygdala circuitry regulated by ITC clusters. Node size indicates activity level, connection width represents putative functional connection strength.
