Inhibition of neuronal and astrocytic protein degradation in the amygdala impairs contextual fear memory in male rats. (A) Schematic of the experimental design. CRISPR–dCas9 plasmids (from Fig. 1) were injected into the amygdala of male rats (N = 4–5 per group). Four weeks after transfection, animals were trained to contextual fear conditioning and tested 24 h later. In all cases, guide RNAs (gRNAs) targeted the ubiquitin gene Uba52 and proteasome subunit Psmd14. Control animals received only the gRNAs. (B) Performance during the training session. Inhibition of neuronal (SYN–dCas9), but not astrocytic (GFAP–dCas9), protein degradation reduced freezing behavior during the training session relative to controls. (C) Memory retention during the testing session. Inhibition of neuronal (SYN–dCas9) and astrocytic (GFAP–dCas9) protein degradation impaired long-term memory during the testing session. (*) P < 0.05 from control.
