Article Figures & Data
Figures
- Figure 1.
Histology confirmation of this study. A, An illustrative representation showing cannula placement in the ReRh. B, A Nissl-stained coronal section showing the cannula placement in the ReRh. C, A dark-field image showing diffusion of TMR-X muscimol in the ReRh.
- Figure 2.
Re neurons were generally recruited in the encoding phase of trace and delay fear conditioning. A, Animals underwent a 2-d behavioral experiment, in which half of the animals in each group were killed after conditioning and the rest after retrieval test. B, c-Fos+ expression in Re neurons (red square). c-Fos signals were visualized with blue/black reaction products within the nucleus of activated neurons. C, The freezing behavior of TRACE, DELAY, UNPAIRED, and NoCOND groups. Freezing levels of the conditioning (n = 12 per group) and test trials (n = 6 per group) are presented in left panel, respectively. The middle panel shows the averaged freezing levels of the UNPAIRED group (gray line with SEM) and the divergent high (solid lines) or low (dashed lines) freezing levels of each animal during retrieval test. The right panel shows the average c-Fos+ count of the UNPAIRED group (gray bar with SEM) and the counts of high freezing (open circles; behaviors shown in solid lines) and low freezing (filled circles; behaviors shown in dashed lines) animals based on their behavior on trial 3 (n = 3 each). D, Group differences in c-Fos+ counts of the Re after conditioning (upper panel) and test (lower panel); *p < 0.05. NS, not significant.
- Figure 3.
The ReRh was critically involved during the acquisition of trace fear conditioning. A, Experimental design. Animals underwent a 2-d behavioral experiment, in which the animals received drug infusion immediately before conditioning (day 1). B, Injector tip placements of all the animals included in data analyses at levels −1.92, −2.16, −2.52, and −3.00 mm posterior relative to bregma. The gray areas marked in the atlas are the Re and ventral Re. C, The freezing behavior of V-TRACE (n = 7), M-TRACE (n = 6), V-DELAY (n = 6), and M-DELAY groups (n = 5) when injections were performed before conditioning.
- Figure 4.
The ReRh was not involved during the consolidation of trace fear conditioning. A, Experimental design. Animals underwent a 2-d behavioral experiment, in which the animals received drug infusion immediately after conditioning (day 1). B, Injector tip placements of all the animals included in data analyses at levels −1.92, −2.16, −2.52, and −3.00 mm posterior relative to bregma. The gray areas marked in the atlas are the Re and ventral Re. C, The freezing behavior of C-TRACE (n = 8), M-TRACE (n = 7), C-DELAY (n = 7), and M-DELAY groups (n = 7) when injections were performed after conditioning.
- Figure 5.
The ReRh was not involved during the retrieval of trace fear conditioning. A, Experimental design. Animals underwent a 2-d behavioral experiment, in which the animals received drug infusion immediately before test (day 2). B, Injector tip placements of all the animals included in data analyses at levels −1.92, −2.16, −2.52, and −3.00 mm posterior relative to bregma. The gray areas marked in the atlas are the Re and ventral Re. C, The freezing behavior of V-TRACE (n = 5), M-TRACE (n = 7), V-DELAY (n = 7), and M-DELAY groups (n = 7) when injections were performed before retrieval test.
- Figure 6.
Retrieval of trace fear acquired under ReRh inactivation reprised under ReRh inactivation. A, Experimental design. Animals underwent a 2-d behavioral experiment, in which the animals received drug infusion immediately before both conditioning and retrieval test. B, Injector tip placements of all the animals included in data analyses at levels −1.92, −2.16, −2.52, and −3.00 mm posterior relative to bregma. The gray areas marked in the atlas are the Re and ventral Re. C, The freezing behavior of SAL-SAL (n = 10), MUS-SAL (n = 9), and MUS-MUS groups (n = 9) when the injections were performed before both conditioning and retrieval test.
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