dreadd  (Addgene inc)

Journal: Neurobiology of Stress

Article Title: Norepinephrine neurons in the locus coeruleus and the nucleus of the solitary tract drive different stress-related behavioral outputs in mice

doi: 10.1016/j.ynstr.2026.100802

Figure Lengend Snippet: DREADD expression in noradrenergic neurons. DREADD/mCherry-inducing viral vectors were administered to the NTS and LC of DBH-CRE mice. (A) mCherry-expressing neurons (red) co-labeled with TH (green) in the NTS. Few off-target mCherry-positive neurons were observed in the area postrema (AP). (B) Over 90% of the mCherry-expressing neurons in the NTS were immunopositive for TH. ( C ) mCherry-expressing neurons co-labeled with TH in the LC. ( D ) Over 90% of the mCherry-expressing neurons in the LC were immunopositive for TH. ( E ) cFos staining in the LC 90 min following DCZ injection IP in mice expressing the mCherry control virus (Control) or the Gq-DREADD. ( F ) cFOS was expressed in a significantly greater number of LC neurons following DCZ injection in the DREADD-expressing compared to the control virus-expressing mice. Scale bars = 100 μm.

Article Snippet: In addition, a virus that induces the expression of mCherry without a DREADD (AAV9-hSyn-DIO-mCherry, 0.66 ∗ 3 13 GC/mL, Addgene 50459-AAV9) was injected bilaterally into the NTS as a control (CTRL).

Techniques: Expressing, Labeling, Staining, Injection, Control, Virus

Journal: Neurobiology of Stress

Article Title: Norepinephrine neurons in the locus coeruleus and the nucleus of the solitary tract drive different stress-related behavioral outputs in mice

doi: 10.1016/j.ynstr.2026.100802

Figure Lengend Snippet: Chemogenetic activation of PVN-projecting NE neurons induced multiple stress behaviors in male and female mice. (A) A Cre-dependent, Gq-DREADD-expressing retrograde AAV was injected into the PVN of DBH-Cre mice. (B) Noradrenergic neurons in the NTS and the LC were labeled with tyrosine hydroxylase immunofluorescence (TH-ir); sparse expression of mCherry immunofluorescence (mCherry-ir) was observed in the LC and NTS. (C) mCherry-immunopositive axons were visible in the PVN. (D) No mCherry immunofluorescence was detected in the rostral ventro-lateral medulla (RVLM). (E, F) DCZ activation of NE neurons retrogradely labeled from the PVN decreased the exploratory behaviors of walking (E) and rearing (F). (G, H) DCZ caused a trend toward an increase in the time spent grooming (G) and caused a significant increase in immobility (H). (I) Regression analysis revealed a strong correlation between time spent in grooming and immobility behaviors in these mice. (J) Food intake was not significantly affected by Gq-DREADD activation of PVN-projecting NE neurons. White arrows in panel B indicate co-localization of mCherry and TH immunofluorescence.

Article Snippet: In addition, a virus that induces the expression of mCherry without a DREADD (AAV9-hSyn-DIO-mCherry, 0.66 ∗ 3 13 GC/mL, Addgene 50459-AAV9) was injected bilaterally into the NTS as a control (CTRL).

Techniques: Activation Assay, Expressing, Injection, Labeling, Immunofluorescence

Journal: Neurobiology of Stress

Article Title: Norepinephrine neurons in the locus coeruleus and the nucleus of the solitary tract drive different stress-related behavioral outputs in mice

doi: 10.1016/j.ynstr.2026.100802

Figure Lengend Snippet: Chemogenetic activation of NE neurons in male and female mice. ( A ) Experimental design: A Gq-DREADD-expressing AAV was injected bilaterally into the NTS of DBH-Cre mice and the mice were subjected subsequently to I.P. injections of CNO and vehicle at a two-week interval, in a cross-over design. Inset: Viral expression of the DREADD was confirmed by confocal imaging of mCherry fluorescence in the NTS. ( B ) Chemogenetic stimulation of NE neurons in the NTS activated the HPA axis, as indicated by an increase in serum corticosterone in both males and females. ( C, D ) Vehicle-injected control males spent more time walking (C) and rearing (D) than control females; chemogenetic activation of NTS NE neurons significantly decreased walking and rearing in both males and females and abolished the sex difference in the response. ( E ) Grooming behavior after vehicle injection did not differ between males and females; CNO caused a decrease in the time spent grooming in both sexes. ( F ) CNO caused a robust increase in the time both males and females spent in immobility, with no differences between sexes.

Article Snippet: In addition, a virus that induces the expression of mCherry without a DREADD (AAV9-hSyn-DIO-mCherry, 0.66 ∗ 3 13 GC/mL, Addgene 50459-AAV9) was injected bilaterally into the NTS as a control (CTRL).

Techniques: Activation Assay, Expressing, Injection, Imaging, Fluorescence, Control

Journal: Neurobiology of Stress

Article Title: Norepinephrine neurons in the locus coeruleus and the nucleus of the solitary tract drive different stress-related behavioral outputs in mice

doi: 10.1016/j.ynstr.2026.100802

Figure Lengend Snippet: Chemogenetic activation of NE neurons in the LC in male and female mice. (A) Experimental design: A Gq-DREADD-expressing AAV was injected bilaterally into the LC of DBH-Cre mice, then the mice were injected IP with DCZ and vehicle at a two-week interval, in a cross-over design. Inset: Viral expression of the DREADD was confirmed by confocal imaging of mCherry fluorescence in the LC. (B ) Chemogenetic stimulation of NE neurons in the LC activated the HPA axis, as indicated by an increase in serum corticosterone in both males and females. ( C-F) DCZ injections IP caused a decrease in the time spent walking (C) and rearing (D) and an increase in the time spent grooming (E), but had no effect on the average time spent in immobility (E). (F) There was a moderate but significant decrease in food intake in response to DCZ. There was no significant effect of sex on any of the behavioral measures.

Article Snippet: In addition, a virus that induces the expression of mCherry without a DREADD (AAV9-hSyn-DIO-mCherry, 0.66 ∗ 3 13 GC/mL, Addgene 50459-AAV9) was injected bilaterally into the NTS as a control (CTRL).

Techniques: Activation Assay, Expressing, Injection, Imaging, Fluorescence

Journal: Neurobiology of Stress

Article Title: Norepinephrine neurons in the locus coeruleus and the nucleus of the solitary tract drive different stress-related behavioral outputs in mice

doi: 10.1016/j.ynstr.2026.100802

Figure Lengend Snippet: Effects of manipulation of NTS-NE neurons on sickness-like behaviors. (A) Excitatory Gq-DREADD-expressing, inhibitory Gi-DREADD-expressing, or mCherry control (CTRL) viral vectors were injected bilaterally into the NTS of DBH-Cre mice, after which they were subjected to a battery of sickness-related behavioral tests. ( B ) mCherry expression in the NTS following control (CTRL), Gq-DREADD- (Gq), and Gi-DREADD (Gi)-expressing virus injection. ( C-E ) In the open field test, DCZ injection in Gq-DREADD-expressing mice caused a significant decrease in the total distance travelled (C) and the time spent in movement (D), and an increase in the time spent in immobility (E) compared to both Gi-DREADD-expressing and CTRL mice. ( F ) Time spent in the center of the open field did not differ among groups. ( G ) Food intake was significantly decreased by DCZ in the Gq-DREADD-injected mice compared to the Gi-DREADD-injected and CTRL mice. ( H ) Using the von Frey test, half the Gq-DREADD-injected mice were not responsive to mechanical stimuli, which was not observed in the Gi-DREADD-injected or CTRL mice. ( I ) Among the mechano-responsive mice, the von Frey threshold was significantly reduced in the Gq-DREADD-injected mice compared to the Gi-DREADD-injected and CTRL mice. ∗∗p < 0.01, ∗∗∗p < 0.001.

Article Snippet: In addition, a virus that induces the expression of mCherry without a DREADD (AAV9-hSyn-DIO-mCherry, 0.66 ∗ 3 13 GC/mL, Addgene 50459-AAV9) was injected bilaterally into the NTS as a control (CTRL).

Techniques: Expressing, Control, Injection, Battery, Virus

Journal: bioRxiv

Article Title: The importance of M1 muscarinic receptor phosphorylation in learning and memory

doi: 10.64898/2026.03.23.713145

Figure Lengend Snippet: M1-WT-HA (n=11-14) (A) , M1-KO (n=13-16) (B) or M1-PD-HA (n=11-14) (C) mice were treated with 1.5 mg/kg scopolamine +/-10 mg/kg VU846 30 mins prior to training in a fear conditioning paradigm. Mice were then returned to the same environment 24 hrs later for contextual memory retrieval whereby a reduced level of freezing indicates impaired memory. The response in vehicle treated animals across strains was also compared (D) . 2-way ANOVA with Tukey’s post-hoc correction for multiple comparisons, *p<0.05, ***p<0.001, ****p<0.0001, ns=not significant. (E ) Representative images of CA1 hippocampal region of HA-tagged M1-WT, M1-DREADD, M1-PD and M1-DREADD-PD stained with HA antibody demonstrating location of the receptor (green). Images at 40X magnification, scale bar = 50 µm

Article Snippet: The drugs utilised in this study were the pan-muscarinic antagonist, to induce a learning and memory (LM) deficit, scopolamine hydrobromide (Sigma) at 0.5-3 mg/kg doses; the M1 positive allosteric modulator (PAM) VU0486846 (VU846) at 10-100 mg/kg; and the M1-DREADD activating ligand clozapine-n-oxide (CNO) (Tocris) at 0.3 mg/kg.

Techniques: Staining

Journal: bioRxiv

Article Title: The importance of M1 muscarinic receptor phosphorylation in learning and memory

doi: 10.64898/2026.03.23.713145

Figure Lengend Snippet: (A) Male and female M1-WT-HA (n=11) and M1-PD (n=12) mice were treated with the M1-PAM VU846 30 mins prior to fear conditioning and returned to the chamber 24 hrs later for contextual memory retrieval. 2-way ANOVA ****p<0.0001 effect of strain, no significant effect of drug overall p=0.12, Bonferroni’s post-hoc correction for multiple comparisons between vehicle and VU846 for each strain, ns= not significant. (B & C) Male M1-DREADD mice were treated with 0.3 mg/kg of clozapine-N-oxide (CNO), an orthosteric agonist of the DREADD receptor, or vehicle (n=4-5 per group) 30 mins prior to training in a fear conditioning paradigm and then returned to the same environment 24 hrs later for contextual memory retrieval (B) or presentation of the tone in an altered environment 48 hrs later for cued memory retrieval (C) whereby a reduced level of freezing indicates impaired memory. (D) WT mice (n=7-9 per group) were also treated with 0.3 mg/kg CNO in a separate experiment demonstrating no effect of CNO. 2-way ANOVA with Dunnett’s post-hoc correction for multiple comparisons, ****p<0.0001, all other comparisons p>0.05.

Article Snippet: The drugs utilised in this study were the pan-muscarinic antagonist, to induce a learning and memory (LM) deficit, scopolamine hydrobromide (Sigma) at 0.5-3 mg/kg doses; the M1 positive allosteric modulator (PAM) VU0486846 (VU846) at 10-100 mg/kg; and the M1-DREADD activating ligand clozapine-n-oxide (CNO) (Tocris) at 0.3 mg/kg.

Techniques:

Journal: bioRxiv

Article Title: The importance of M1 muscarinic receptor phosphorylation in learning and memory

doi: 10.64898/2026.03.23.713145

Figure Lengend Snippet: Male M1-DREADD mice were treated with 0.01 - 0.3 mg/kg of clozapine-N-oxide (CNO), an orthosteric agonist of the DREADD receptor, or vehicle (n=5-9 per group) 30 mins prior to training in a fear conditioning paradigm and then returned to the same environment 24 hrs later for contextual memory retrieval. Data presented as freezing level normalised to the highest freezing response. One way ANOVA with Bonferroni’s post hoc correction for multiple comparisons to vehicle treatment group *p<0.05. All other comparisons not significant.

Article Snippet: The drugs utilised in this study were the pan-muscarinic antagonist, to induce a learning and memory (LM) deficit, scopolamine hydrobromide (Sigma) at 0.5-3 mg/kg doses; the M1 positive allosteric modulator (PAM) VU0486846 (VU846) at 10-100 mg/kg; and the M1-DREADD activating ligand clozapine-n-oxide (CNO) (Tocris) at 0.3 mg/kg.

Techniques:

Journal: bioRxiv

Article Title: External Globus Pallidus Arkypallidal Circuit Dynamics Gate Risk-Taking Behavior

doi: 10.64898/2026.03.20.713182

Figure Lengend Snippet: (a) Experimental diagram. Npas1-Cre-TdTomato mice received bilateral GPe injections of Cre-dependent AAV8-hSyn-DIO-hM4D(Gi)-mCherry or AAV8-hSyn-DIO-hM3D(Gq)-mCherry, with Cre-negative littermates serving as controls. All animals received C21 prior to testing, ensuring equivalent drug exposure across groups. Mice were tested on the elevated plus maze (EPM) 5 weeks post-surgery. Behavioral sessions were video-recorded for subsequent analysis. (b) Time spent in closed arms, center, and open arms during the EPM shows the expected preference for closed arms across all groups, with no effect of GPe NPAS1 manipulation on arm occupancy (two-way mixed ANOVA, maze compartment F (2,52) = 122.8, p = 2.003e-20; group F (2,26) = 1.546, p = 0.2319). (c) Number of open-arm entries does not differ across groups, indicating no effect of GPe NPAS1 manipulation on exploration of these areas (ANOVA, group F (2,26) = 1.048, p = 0.365). (d) Percent time spent in the open arms in the EPM is comparable across control, hM4D(Gi), and hM3D(Gq) mice, consistent with preserved global EPM performance (ANOVA, group F (2,55) = 0.4928, p = 0.6136). (e) Empirical cumulative distribution functions (ECDFs) of frame-wise horizontal movement in the open arms during the EPM show highly overlapping movement distributions across groups, illustrating the absence of gross shifts in locomotor behavior within high-risk regions of the maze. Pairwise Kolmogorov–Smirnov tests detected statistically significant but very small distributional differences (KS D = 0.02–0.05; FDR-corrected p < 0.001), consistent with negligible effect sizes that do not reflect meaningful differences in open-arm movement dynamics. (f) Distance traveled (two-way mixed ANOVA, group x time F (238,3094) = 0.8741, p = 0.9131), (g) speed (two-way mixed ANOVA, group x time F (238,3094) = 0.8742, p = 0.9129), and (h) acceleration (two-way mixed ANOVA, group x time F (238,3094) = 1.037, p = 0.3419) over time are comparable across control, hM4D(Gi), and hM3D(Gq) mice, indicating preserved global locomotor output across the session. Frame-wise polar histograms of heading direction during EPM show (i) control mice exhibit a modest but significant preference for a closed-arm-oriented heading (Rayleigh test, r = 0.005399, p = 0.001871). (j) hM4D(Gi) mice show a statistically significant, strong preferred closed arm heading (Rayleigh test, r = 0.01707, p = 1.225e-16). (k) In contrast, GPe NPAS1 hM4D(Gq) mice do not exhibit a statistically significant preferred heading orientation (Rayleigh test, r = 0.001264, p = 0.7505). (l) Pose features extracted from video tracking show bound box area across time was decreased for hM3D(Gq) mice compared to control mice across all EPM areas (two-way mixed ANOVA, group x time F (238,3094) = 1.180, p = 0.03497; post hoc control v hM3D(Gq) p = 0.03348). (m) Similarly, box aspect ratio over time was decreased for hM3D(Gq) mice compared to control mice (two-way mixed ANOVA, group x time F (238,3094) = 1.181, p = 0.03486; post hoc control v hM3D(Gq) p = 0.04464). (n) There were no group differences in the change in aspect ratio across time (two-way mixed ANOVA, group x time F (238,3094) = 0.08639, p = 0.06231). Dots represent individual data points, error bars or shaded bands represent standard error of the mean (SEM). For polar plots, 32 bins were computed to generate 11.25 degree bars for histogram densities.

Article Snippet: The Gi/o-coupled DREADD vector AAV8-hSyn-DIO-hM4D(Gi)-mCherry (plasmid #44362) and the Gq-coupled DREADD vector AAV8-hSyn-DIO-hM3D(Gq)-mCherry (plasmid #44361) were obtained from Addgene.

Techniques: Control

Journal: bioRxiv

Article Title: External Globus Pallidus Arkypallidal Circuit Dynamics Gate Risk-Taking Behavior

doi: 10.64898/2026.03.20.713182

Figure Lengend Snippet: (a) Experimental diagram. Npas1-Cre-TdTomato mice received bilateral GPe injections of Cre-dependent AAV8-hSyn-DIO-hM4D(Gi)-mCherry or AAV8-hSyn-DIO-hM3D(Gq)-mCherry, with Cre-negative littermates serving as controls. All animals received C21 prior to testing, ensuring equivalent drug exposure across groups. Mice were tested on the elevated plus maze (EPM) 5 weeks post-surgery. Behavioral sessions were video-recorded for subsequent analysis. (b) Time spent in closed arms, center, and open arms during the EPM shows the expected preference for closed arms across all groups, with no effect of GPe NPAS1 manipulation on arm occupancy (two-way mixed ANOVA, maze compartment F (2,52) = 122.8, p = 2.003e-20; group F (2,26) = 1.546, p = 0.2319). (c) Number of open-arm entries does not differ across groups, indicating no effect of GPe NPAS1 manipulation on exploration of these areas (ANOVA, group F (2,26) = 1.048, p = 0.365). (d) Percent time spent in the open arms in the EPM is comparable across control, hM4D(Gi), and hM3D(Gq) mice, consistent with preserved global EPM performance (ANOVA, group F (2,55) = 0.4928, p = 0.6136). (e) Empirical cumulative distribution functions (ECDFs) of frame-wise horizontal movement in the open arms during the EPM show highly overlapping movement distributions across groups, illustrating the absence of gross shifts in locomotor behavior within high-risk regions of the maze. Pairwise Kolmogorov–Smirnov tests detected statistically significant but very small distributional differences (KS D = 0.02–0.05; FDR-corrected p < 0.001), consistent with negligible effect sizes that do not reflect meaningful differences in open-arm movement dynamics. (f) Distance traveled (two-way mixed ANOVA, group x time F (238,3094) = 0.8741, p = 0.9131), (g) speed (two-way mixed ANOVA, group x time F (238,3094) = 0.8742, p = 0.9129), and (h) acceleration (two-way mixed ANOVA, group x time F (238,3094) = 1.037, p = 0.3419) over time are comparable across control, hM4D(Gi), and hM3D(Gq) mice, indicating preserved global locomotor output across the session. Frame-wise polar histograms of heading direction during EPM show (i) control mice exhibit a modest but significant preference for a closed-arm-oriented heading (Rayleigh test, r = 0.005399, p = 0.001871). (j) hM4D(Gi) mice show a statistically significant, strong preferred closed arm heading (Rayleigh test, r = 0.01707, p = 1.225e-16). (k) In contrast, GPe NPAS1 hM4D(Gq) mice do not exhibit a statistically significant preferred heading orientation (Rayleigh test, r = 0.001264, p = 0.7505). (l) Pose features extracted from video tracking show bound box area across time was decreased for hM3D(Gq) mice compared to control mice across all EPM areas (two-way mixed ANOVA, group x time F (238,3094) = 1.180, p = 0.03497; post hoc control v hM3D(Gq) p = 0.03348). (m) Similarly, box aspect ratio over time was decreased for hM3D(Gq) mice compared to control mice (two-way mixed ANOVA, group x time F (238,3094) = 1.181, p = 0.03486; post hoc control v hM3D(Gq) p = 0.04464). (n) There were no group differences in the change in aspect ratio across time (two-way mixed ANOVA, group x time F (238,3094) = 0.08639, p = 0.06231). Dots represent individual data points, error bars or shaded bands represent standard error of the mean (SEM). For polar plots, 32 bins were computed to generate 11.25 degree bars for histogram densities.

Article Snippet: The Gi/o-coupled DREADD vector AAV8-hSyn-DIO-hM4D(Gi)-mCherry (plasmid #44362) and the Gq-coupled DREADD vector AAV8-hSyn-DIO-hM3D(Gq)-mCherry (plasmid #44361) were obtained from Addgene.

Techniques: Control

Journal: iScience

Article Title: Dentate gyrus network regulation by somatostatin- and parvalbumin-expressing interneurons differentially impacts spatial memory processing

doi: 10.1016/j.isci.2026.115067

Figure Lengend Snippet: Effects of SST+ interneuron activation across different stages of spatial memory processing (A) Male and female SST-CRE mice ( n = 9 animals/group for encoding and consolidation; n = 14–15 animals/group for retrieval) are transduced to express Cre-dependent hM3Dq-mCitrine or EGFP (control) in DG. Beginning four weeks after viral transduction, SST+ interneurons were activated separately either during OLM encoding, consolidation, or retrieval, with two weeks of rest between OLM trials, which ended with a final trial in which vehicle is administered prior to encoding. (B) Timing of compound 21 (C21) administration relative to OLM encoding, consolidation, or retrieval. Mouse interaction with the moved vs. unmoved object is quantified to generate the OLM discrimination index (DI). (C–E) Discrimination index scores for encoding (C), consolidation (D), and retrieval (E) sessions in mice expressing EGFP or hM3Dq in SST+ interneurons. two-way ANOVA (Phase × AAV) revealed a significant main effect of AAV (F(1,58) = 7.40, p = 0.0086), indicating that the chemogenetic activation of SST+ interneurons influences DI performance independent of behavioral phase. Neither the main effect of Phase (F(2,58) = 1.69, p = 0.1936) nor the Phase × AAV interaction reached significance (F(2,58) = 2.41, p = 0.0985), though the interaction showed a trend. Closer inspection of the data showed the largest effects of SST+ interneuron activation on OLM encoding ( p = 0.0047, Tukey’s test) and retrieval ( p = 0.046, Tukey’s test), but had no effect on consolidation ( p = 0.8804). (F) Vehicle administration did not affect OLM encoding ( p = 0.755, n = 8–9 animals/group). For all panels, # p < 0.1, ∗ p < 0.05. Data are presented as mean ± SEM.

Article Snippet: DREADD agonist compound 21 , Tocris , 5548.

Techniques: Activation Assay, Control, Transduction, Expressing