Journal: Translational Psychiatry

Article Title: Enhancing dopaminergic signaling and histone acetylation promotes long-term rescue of deficient fear extinction

doi: 10.1038/tp.2016.231

Figure Lengend Snippet: Rescue of impaired fear extinction induces a select transcriptional response in the medial prefrontal cortex (mPFC) and amygdala. ( a ) Scheme illustrating experimental paradigm. Mice were subjected to ‘normal' 0.6 mA fear conditioning (Cond.) in context A and fear extinction (Ext training in context B). All groups were conditioned on control diet (Ctl) before mice were subjected to dietary zinc restriction (ZnR) for 14 days till Ext. ( b ) Heatmap depicting differentially expressed genes in the mPFC (491) and amygdala (52) determined using microarray analysis between non-extinguishing Ctl diet-fed mice and extinguishing ZnR-fed mice. Each line depicts a differentially regulated gene; each row depicts the gene expression in each animal. Blue and red indicate low and high levels of expression, respectively. ( c ) Histogram showing the biological process to which the differentially regulated genes belong (orange, number of differentially regulated genes per biological process; green, significance of enrichment).

Article Snippet: mPFC and amygdala tissue punches were formaldehyde crosslinked and chromatin immunoprecipitation was performed following a modification of the Active Motif ChIP-IT Express kit protocol with an ac H4 antibody.

Techniques: Control, Microarray, Gene Expression, Expressing

Journal: Translational Psychiatry

Article Title: Enhancing dopaminergic signaling and histone acetylation promotes long-term rescue of deficient fear extinction

doi: 10.1038/tp.2016.231

Figure Lengend Snippet: Rescue of impaired fear extinction enhances expression of genes coding for dopamine D1 (Drd1a) and D2 (Drd2) receptors. ( a ) Scheme illustrating experimental paradigm for b , c . Cond, ‘normal' 0.6 mA fear conditioning; Ext, extinction training; Exp, fear expression; Ctl, control diet; ZnR, dietary zinc restriction. Expression of dopaminergic genes in the medial prefrontal cortex (mPFC) and amygdala following successful rescue of impaired fear extinction ( b ) and following fear expression ( c ). * P <0.05 Ctl versus ZnR, ** P <0.01 Ctl versus ZnR. n =3–8 per group. ( d ) Scheme illustrating experimental paradigm for e . Cond., ‘normal' (0.6 mA) conditioning; ER, extinction retrieval; SR, spontaneous recovery; RN, fear renewal. ( e ) Lower freezing was observed in L-dopa-treated mice when compared with VEH-treated during Ext. trial blocks 7–8 through to 15–16 and also during ER. n =10 per group. * P <0.05 post hoc testing L-dopa versus VEH. ( f ) Scheme illustrating experimental paradigm for g . Cond., ‘weak' (0.3 mA) conditioning. ( g ) Lower freezing was observed in L-dopa-treated mice when compared with VEH-treated mice during ER. n =7–8 per group. * P <0.05 post hoc testing L-dopa versus VEH.

Article Snippet: mPFC and amygdala tissue punches were formaldehyde crosslinked and chromatin immunoprecipitation was performed following a modification of the Active Motif ChIP-IT Express kit protocol with an ac H4 antibody.

Techniques: Expressing, Control

Journal: Translational Psychiatry

Article Title: Enhancing dopaminergic signaling and histone acetylation promotes long-term rescue of deficient fear extinction

doi: 10.1038/tp.2016.231

Figure Lengend Snippet: Enhancing histone acetylation promotes enduring and context-independent rescue of newly formed extinction memories. ( a ) Scheme illustrating experimental paradigm for b , c . Cond., ‘normal' fear conditioning; Exp, fear extinction; Exp, fear expression; Ctl, control diet; ZnR, zinc-restricted diet. n =3–8 per group. ( b ) Enhanced abundance of acH4 was observed in the promoter region of Drd2 following fear extinction in the medial prefrontal cortex (mPFC). ( c ) No changes in any group were observed following fear expression. ( d ) Scheme illustrating experimental paradigm for e – p . ER, extinction retrieval; SR, spontaneous recovery; RN, renewal. ( e ) Freezing was lower in MS-275 administered mice during ER, SR and RN. n =9–10 per group. * P <0.05 post hoc testing MS-275 versus VEH. ( f ) Representative epifluorescent photomicrograph of a coronal section (Bregma +1.78 mm) stained for acH4 immunoreactivity. IL, infralimbic cortex; PL, prelimbic cortex. Scale bar=500 μm. ( g ) Representative epifluorescent photomicrographs delineating the cortical layers within the IL. Scale bar=100 μm. ( h , i ) Enhanced acH4 epifluorescence was observed in NeuN-positive (NeuN+) cell populations following MS-275 administration and following successful fear extinction (CS+) in layer II and in layer III, but not layer V/VI, compared with vehicle-treated counterparts (VEH). ** P <0.01 post hoc testing MS-275 versus VEH in conditioned (CS+) groups. n =4–6/group. Scale bar=20 μm. ( j ) Representative epifluorescent photomicrograph of a coronal section (Bregma −1.56 mm) delineating the basal amygdala region quantified. BA, basal amygdala; Ce, central amygdala; LA, lateral amygdala. Scale bar=250 μm. ( k , l ) Enhanced acH4 epifluorescence was observed in NeuN-positive nuclei (NeuN+) only successful fear extinction acquisition and MS-275 administration. Scale bar=20 μm. ** P <0.01 post hoc testing MS-275 versus VEH in conditioned (CS+) groups. n =4–6/group. ( m ) Representative epifluorescent photomicrograph of a coronal section (Bregma +1.78 mm) stained for acH4 immunoreactivity. IL, infralimbic cortex; PL, prelimbic cortex. Scale bar=500 μm. ( n ) Representative epifluorescent photomicrographs delineating the cortical layers within the PL. Scale bar=100 μm. ( o , p ) Enhanced acH4 epifluorescence was observed in NeuN-positive (NeuN+) cell populations following successful fear extinction (CS+) in mice administered VEH and MS-275 to a similar level in layer II, but not layers II or V/VI, compared to vehicle-treated counterparts (VEH). Scale bar=20 μm. * P <0.05, ** P <0.01 post hoc testing MS-275 versus VEH in conditioned (CS+) groups. n =4–6 per group.

Article Snippet: mPFC and amygdala tissue punches were formaldehyde crosslinked and chromatin immunoprecipitation was performed following a modification of the Active Motif ChIP-IT Express kit protocol with an ac H4 antibody.

Techniques: Expressing, Control, Staining