fear conditioning chambers  (Med Associates Inc)

Journal: Neural Regeneration Research

Article Title: Regulator of G protein signaling 6 mediates exercise-induced recovery of hippocampal neurogenesis, learning, and memory in a mouse model of Alzheimer’s disease

doi: 10.4103/NRR.NRR-D-23-01993

Figure Lengend Snippet: RGS6 in DG NPCs is required for running-induced cognitive improvements in APP SWE mice. (A) Schematic outlining experimental design. Mice were placed in cages containing either fixed (control) or free (running) wheels for 8 weeks. Mice underwent hippocampal-based learning and memory behavioral tasks after 4 weeks (Y-maze [B]) and 8 weeks (Y-maze [C] and contextual fear conditioning (CFC, [D]) of wheel treatment. (B, C) Multi-way analysis of variance with Tukey’s post hoc adjustment was used to analyze the effects of and interactions between genotype, sex, time, and wheel treatment after 4 (B) or 8 weeks (C) of wheel treatment. Top: % Spontaneous alternations— Significant effects of genotype ( F 3,154 = 16.261, P = 0.000) and wheel treatment ( F 1,154 = 52.906, P = 0.000), as well as their interaction ( F 3,154 = 19.638, P = 0.000) were observed. No significant effects of sex or time were observed. Bottom: % Time spent in novel arm— Significant effects of genotype ( F 3,154 = 30.835, P = 0.000) and wheel treatment ( F 1,154 = 22.496, P = 0.000), as well as their interaction ( F 3,154 = 7.652, P = 0.000) were observed. No significant effects of sex or time were observed. (D) Multi-way ANOVA with Tukey’s post hoc adjustment was used to analyze the effects of and interactions between genotype, sex, and wheel treatment. A significant effect of genotype ( F 3,55 = 6.217, P = 0.001) and its interaction with wheel treatment ( F 3,55 = 3.898, P = 0.013) were observed. No significant effects of sex or wheel treatment were observed. Data are expressed as mean ± SEM. * P < 0.05, ** P < 0.01, *** P < 0.001. (Fixed wheel: n = 8 RGS6 WT DG mice; n = 11 RGS6 KO DG mice; n = 10 RGS6 WT DG ; APP SWE mice; n = 12 RGS6 KO DG ; APP SWE mice. Free wheel: n = 7 RGS6 WT DG mice; n = 9 RGS6 KO DG mice; n = 10 RGS6 WT DG ; APP SWE mice; n = 15 RGS6 KO DG ; APP SWE mice). DCX: Doublecortin; DG: dentate gyrus; GFP: green fluorescent protein; IHC: immunohistochemistry; NPCs: neuronal progenitor cells; RGS6: Regulator of G protein signaling 6.

Article Snippet: For each trial, mice are placed in a fear conditioning box (Med Associates NIR VFC System, Fairfax, VT, USA) with a steel wire bottom.

Techniques: Control, Immunohistochemistry

Journal: Frontiers in Genetics

Article Title: Affective phenotypes in heterozygous LRRK2 R1441G knock-in mice

doi: 10.3389/fgene.2025.1629897

Figure Lengend Snippet: Evidence for depression-related behavioural phenotypes in heterozygous KI +/− mice. (A) All mice showed a preference for the sucrose solution with the percentage of sucrose solution exceeding 50%, but a reduction was evident in the KI +/− group, whose preference was significantly lower than KI +/+ mice ( p < 0.05 *) and marginally below WT mice ( p = 0.06 # ) based on pairwise comparisons by Fisher’s LSD. (B) Latency to shuttle (left) and percentage of escape failures (right) in the conditioned active avoidance task illustrate the impact of prior exposure to inescapable shock versus escapable shock. This difference resulted in a significant main effect of pre-exposure experience (* p < 0.01). (C) Immobility time (as a percentage) across successive 1-min bins on days 1 and 2 are separately depicted, showing earlier and stronger immobility in KI+/− and KI+/+ mice than WT mice (especially on Day 2). (D) Mean immobility time (as a percentage) in the FST is shown for the full 10-min test (bins 1–10, left) and the last 6 min (bins 5–10, right). Both KI+/− and KI+/+ mice exhibited significantly higher immobility than WT mice in post hoc pairwise comparisons ( p < 0.05 *). The SPT and FST were conducted in mice from Cohort A. n = 12 (6♀+ 6♂) per genotype. The LH experiment included mice in both cohorts A and B. n = 12 (6♀+ 6♂) per genotype per pre-exposure condition. All data are presented as the mean ± SE. Overlaid scatter points represent data from individual mice (green dots = ♂; pink dots = ♀).

Article Snippet: Two conditioned freezing chambers (MED-VFC-USB-M, Med Associates, VT, United States) were used.

Techniques:

Journal: Frontiers in Genetics

Article Title: Affective phenotypes in heterozygous LRRK2 R1441G knock-in mice

doi: 10.3389/fgene.2025.1629897

Figure Lengend Snippet: Selected phenotypes in anxiety-related behaviour. (A) The distribution of time spent in the open arms of the EPM relative to time in all arms (in percent) provides a measure of anxiety-like behaviour. A significant difference was detected using Fisher’s LSD test between KI +/− and WT mice (*), while the difference between KI +/− and KI +/+ did not achieve significance (# at p = 0.09). The EPM test included mice in both cohort A and B. n = 24 (12♀+ 12♂) per genotype. Overlaid scatter points represent data from individual mice (green dots = ♂; pink dots = ♀). (B) The expression of conditioned fear to the tone-CS, assessed 48 h after tone–shock pairings, was indexed by percentage time freezing in the tone test. Tone-freezing was continuously tracked for 8 min after the initial 2-min pre-CS period. The data presented are averaged across three consecutive test days (separate plots for each day are presented in ). (C) The expression of foreground contextual fear conditioning was assessed by returning the animals to the shocked context “A” on the first and third days (1A and 3A) and the neutral context “B” on the second and fourth days (2B and 4B) after conditioning. Higher levels of freezing in context “A” relative context “B” supported the expression of context-specific conditioned fear response. For (B,C) , n = 12 (6♀+ 6♂) per genotype. All data are presented as the mean ± SE.

Article Snippet: Two conditioned freezing chambers (MED-VFC-USB-M, Med Associates, VT, United States) were used.

Techniques: Expressing

Journal: Journal of Advanced Research

Article Title: Hippocampal dipeptidyl peptidase 9 bidirectionally regulates memory associated with synaptic plasticity

doi: 10.1016/j.jare.2024.09.031

Figure Lengend Snippet: The DPP is regulated by memory and regulates memory. 11 (a). Schematic of contextual fear conditioning (CFC) and DPP9 protein detection after memory retrieval. (b). Immunoblotting for DPP9 in the hippocampus 48 h after foot shock(n = 5, t test). (c) Schematic of the AAV vector delivering Cas13d and gRNA. (d) Immunofluorescence staining of injection sites 24 h after KD AVV injection (GFP, green; DPP9, red; DAPI, blue); scale, 1 mm; 100 mm. (e) Immunoblotting for DPP9 in the hippocampus 24 h after KD-AVV injection (n = 3, t test). (f) Schematic of the AAV vector used to deliver DPP9-FLAG. (g) Immunofluorescence staining of injection sites 24 h after OE-AVV injection (GFP, green; FLAG, red; DAPI, blue); scale, 1 mm; 100 mm. (h) Immunoblotting for DPP9 expression in the hippocampus 24 h after OE-induced AVV injection (n = 3, t test). (i, j) Schematic of the CFC after KD and OE AAV injection. (k) Learning curve during CFC training (6 times, 0.8 mA) for KD mice. (n = 8, RM two-way ANOVA) (m) Learning curve during contextual fear conditioning (CFC) training (3 times, 0.5 mA) for OE mice. (n = 10, two-way ANOVA). (l, n) Memory retrieval of CFCs on day 2 in KD and CTR mice (n = 7, t test). *P < 0.05, ** P < 0.01, mean ± SEM.

Article Snippet: The day before the plantar electric shock, the mice were placed in the fear conditioning system (Med Associates, Inc., MED-VFC2-USB-M) for 10 min to allow the mice to habituate to the context.

Techniques: Western Blot, Plasmid Preparation, Immunofluorescence, Staining, Injection, Expressing

Journal: Journal of Advanced Research

Article Title: Hippocampal dipeptidyl peptidase 9 bidirectionally regulates memory associated with synaptic plasticity

doi: 10.1016/j.jare.2024.09.031

Figure Lengend Snippet: Effects of DPP9 and DPP9 inhibitors on long-term potentiation. (a-j) High-frequency stimulation (HFS, 100 Hz) induced CA1 long-term potentiation (LTP). The solution was maintained for at least 1 h and incubated for 20 min for the fEPSP summary. (KD, n = 7; OE, n = 7; Val-BoroPro (VbP), 20 μM; n = 6; VbP, 10 μM; n = 6; sitagliptin, 50 μM; n = 6; t test). (k) Schematic diagram of the VbP intervention in the conditioned fear memory test. The cannula was embedded in the hippocampus of the mice 7 days before adaptation, and 1 μL of 500 μM VBP was given 10 min before 5 kHz sound training. One microliter of 500 μM VbP was added 10 min before memory retrieval. (l) Nissl staining of brain sections at the cannula embedding site. (m) Learning curve during contextual fear conditioning (CFC) training (4 times, 0.8 mA) for 500 μM VbP. (n = 6, two-way ANOVA) (n) The CFC memory test was performed after 2 days of treatment with 500 μM VBP. (n = 6, t test) *P < 0.05, **P < 0.01, *** P < 0.001, mean ± SEM.

Article Snippet: The day before the plantar electric shock, the mice were placed in the fear conditioning system (Med Associates, Inc., MED-VFC2-USB-M) for 10 min to allow the mice to habituate to the context.

Techniques: Incubation, Staining