Journal: bioRxiv

Article Title: Circuit directionality for motivation: lateral accumbens-pallidum, but not pallidum-accumbens, connections regulate motivational attraction to reward cues

doi: 10.1101/474387

Figure Lengend Snippet: Each coronal section represents a range of three sections relative to Bregma (B, in mm). Expression for each animal is plotted at 90% transparency and then per-animal expression is overlaid. Sections run anterior (top) to posterior (bottom). A) Expression map of AAV-hSyn-DIO-hM4D(Gi)-mCherry in VP following CAV2-Cre injections in NAcLSh (i.e., VP → NAcLSh inhibition animals; red). B) Expression map of AAV-hSyn-DIO-mCherry in VP (i.e., controls; black).

Article Snippet: The inhibition group received 0.6 µl of AAV-hSyn-DIO-hM4D(Gi)-mCherry (n = 12, AAV5, UNC Vector Core; n = 4, AAV8, Addgene) in the VP and 1.0 µl CAV-Cre or CAV-Cre-GFP in the NAcLSh.

Techniques: Expressing, Inhibition

Journal: Neuron

Article Title: Visual intracortical and transthalamic pathways carry distinct information to cortical areas

doi: 10.1016/j.neuron.2021.04.017

Figure Lengend Snippet:

Article Snippet: For the experiments involving optogenetic manipulations ( , , and ), AAV1.Syn.DIO.ChrimsonR.tdTomato (120 nl, 3.9 × 10 12 vg/mL, 1:5 dilution in saline solution, UNC vector core, Addgene plasmid # 62723, from Edward Boyden) or AAV1.CAG.DIO.tdTomato (control, 120 nl, 2.6 × 10 13 vg/mL, diluted 1:5 in saline, Addgene viral prep # 28306-AAV1, from Edward Boyden) was injected into AL, PM (single injection) or V1 (5 to 7 injections).

Techniques: Plasmid Preparation, Recombinant, Software

Journal: bioRxiv

Article Title: Hippocampal-medial entorhinal circuit is differently organized along the dorsoventral axis in rodents

doi: 10.1101/2022.05.30.493979

Figure Lengend Snippet: (A) Left: Illustration of the injection site (blue) in the ventral hippocampus (vHS). The approximate positions of horizontal sections used in experiments are indicated by arrows. Right: Schematic representation of a horizontal hippocampal-EC slice showing the position of light stimulation used to activate axons from ventral hippocampal neurons infected with AAV-CaMKIIa-hChR2-EYFP. (B) Z-projected confocal images of biocytin-filled MEC LVa and LVb neurons overlaid with Ctip2 immunolabeling and fluorescent staining of hippocampal axons expressing hChR2-EYFP. The dotted line indicates approximate border between LVb and LVa. Note the strong fluorescence of axonal fibers around Ctip2-negative LVa neurons in the dorsal MEC (top). Right images show the same neurons in black and white contrast. (C) Example EPSC traces recorded from LVa and LVb neurons in the same slice in the dorsal (top) and ventral (middle) MEC in response to 1 ms blue light pulses (bottom). (D) Quantification of synaptic responses of LVa and LVb neurons recorded in the dorsal MEC (LVa(d); LVb(d)). Left: plots of EPSC amplitudes induced by light pulses with increasing intensities. Right: values from the left panel normalized to the highest LVa response at maximum light intensity (11.7 mW/mm 2 ) in each slice. (E) Same analysis as in (D) for LVa and LVb neurons recorded in the ventral MEC (LVa(v); LVb(v)). All data are presented as medians, P25 and P75. Circles represent individual values. Mann-Whitney test: *** p <0.001; ** p <0.01; * p <0.05; ns, not significant.

Article Snippet: For electrophysiological experiments, 70–100 nl of AAV5-CaMKIIa-hChR2(H134R)-EYFP (UNC vector core, Karl Deisseroth virus stock/ Addgene #26969) was injected into either the ventral (AP = −2.8 – −3.1 mm; ML = ±3.4 mm; DV = −4.0 mm (21 mice)) or the dorsal hippocampus (AP = −2 mm; ML = ±2 mm; DV = −1.5 mm (10 mice) or AP = −1.5 mm; ML = ±1.2 mm; DV = −1.4 mm (9 mice)) at a rate of 200 nl per minute using a stainless steel needle (NF33BV, inner tip diameter = 115 μm) connected to a 10 μl NanoFil Syringe (WPI, Sarasota, USA).

Techniques: Injection, Infection, Immunolabeling, Staining, Expressing, Fluorescence, MANN-WHITNEY

Journal: bioRxiv

Article Title: Hippocampal-medial entorhinal circuit is differently organized along the dorsoventral axis in rodents

doi: 10.1101/2022.05.30.493979

Figure Lengend Snippet: (A) Left: Illustration of the injection site (blue) in the dorsal hippocampus (dHS). The approximate positions of horizontal sections used in experiments are indicated by arrows. Right: Schematic representation of a horizontal hippocampal-EC slice showing the position of light stimulation used to activate axons from dorsal hippocampal neurons infected with AAV-CaMKIIa-hChR2-EYFP. (B) Z-projected confocal images of biocytin-filled MEC LVa and LVb neurons overlaid with Ctip2 immunolabeling and fluorescent staining of hippocampal axons expressing hChR2-EYFP. The dotted line indicates approximate border between LVb and LVa. Note the strong fluorescence of axonal fibers in Ctip2-positive LVb and weak but recognizable fluorescence around the Ctip2-negative LVa neuron in the dorsal MEC (top), and no fluorescence in the ventral MEC (bottom). Right images show the same neurons in black and white contrast. (C) Example EPSC traces recorded from LVa and LVb neurons in the same slice in the dorsal (top) and ventral (middle) MEC in response to 1 ms blue light pulses (bottom). (D) Quantification of synaptic responses of LVa and LVb neurons recorded in the dorsal MEC (LVa(d); LVb(d)). Left: plots of EPSC amplitudes induced by light pulses with increasing intensities. Right: values from the left panel normalized to the highest LVa response at maximum light intensity (11.7 mW/mm 2 ) in each slice. (E) Same analysis as in (D) for LVa and LVb neurons recorded in the ventral MEC (LVa(v); LVb(v)). All data are presented as medians, P25 and P75. Circles represent individual values. Mann-Whitney test: *** p <0.001; * p <0.05; ns, not significant.

Article Snippet: For electrophysiological experiments, 70–100 nl of AAV5-CaMKIIa-hChR2(H134R)-EYFP (UNC vector core, Karl Deisseroth virus stock/ Addgene #26969) was injected into either the ventral (AP = −2.8 – −3.1 mm; ML = ±3.4 mm; DV = −4.0 mm (21 mice)) or the dorsal hippocampus (AP = −2 mm; ML = ±2 mm; DV = −1.5 mm (10 mice) or AP = −1.5 mm; ML = ±1.2 mm; DV = −1.4 mm (9 mice)) at a rate of 200 nl per minute using a stainless steel needle (NF33BV, inner tip diameter = 115 μm) connected to a 10 μl NanoFil Syringe (WPI, Sarasota, USA).

Techniques: Injection, Infection, Immunolabeling, Staining, Expressing, Fluorescence, MANN-WHITNEY

Journal: Current biology : CB

Article Title: Dopamine release in the nucleus accumbens core signals perceived saliency

doi: 10.1016/j.cub.2021.08.052

Figure Lengend Snippet: (A) The Kutlu-Calipari-Schmajuk (KCS) model. The model has 4 core components. 1) Associative component: Based on a Rescorla-Wager type prediction error term. 2) Attentional component: Mismatch between predicted/unpredicted stimuli increases novelty, and in turn, attention to all stimuli in the environment. 3) Perceived Saliency: Novelty, attention, and the physical intensity of a stimulus determine perceived saliency. 4) Behavioral response component: Perceived saliency is combined with associative strength to produce a prediction of an outcome. For operant responses, the value of an outcome is calculated as the difference between the unconditioned stimulus value before and after the operant response and predicts future responding in a probabilistic fashion. (B-F) Experiments from Figure 4 were replotted to map onto model simulations. Contingency switch from positive reinforcement to punishment represents a worse than expected outcome – i.e. a negative prediction error. (B) Model simulations of reinforcement behavior (grey line) overlaid with experimental data (blue line). Switching from positive reinforcement to punishment (denoted by dotted line) decreased simulated and actual nose pokes (r=0.79, p<0.0001; n=5). (C) Perceived saliency of (grey), and dopamine responses to (blue), the cue increased. (D) The dopamine response to the cue after the first punisher was increased (paired t-test, t4=2.76, p=0.025). KCS model simulations show that perceived saliency (E, R=0.67, p<0.0001) matches dopamine response patterns during the contingency switch but prediction error does not (F, r=0.092, p=0.2264). (G-M) Optogenetics studies were designed to test whether behavioral responses change in response to increasing dopamine as predicted by changes in perceived saliency. (G) AAV.TH.Cre and AAV.DIO.ChR2 or eYFP were injected into the VTA to achieve specific expression of opsins in dopamine neurons. A fiberoptic was placed above the NAc core to stimulate dopamine release from terminals selectively in the NAc core. (H) A fear conditioning experiment was run where dopamine release was evoked during the cue on 25% of cue-shock pairings. (I) Increasing NAc core dopamine decreased freezing in the ChR2 group compared to eYFP controls (2 way-ANOVA, trial type x group interaction, F(1,20)=17.84, p=0.0004; Sidak’ multiple comparison ChR2-Tone+Stim vs. eYFP-Tone+Stim, p=< 0.0001; ChR2-Tone+Stim vs. ChR2-Tone only p=< 0.0001; n=5-6) and tone only trials in the same animals (Sidak’ multiple comparison ChR2-Tone+Stim vs. ChR2-Tone only, p=0.0002). (J) Simulations from the KCS model show that this behavioral response is predicted by increased perceived saliency, but not other prediction-based parameters. (K) NAc core dopamine release was evoked at the time of the omitted shock during extinction. (L) Dopamine stimulation prevented fear extinction in the ChR2 group compared to eYFP controls (RM ANOVA, Group main effect, F1,9=5.90, p=0.038; Last 4 trial block, unpaired t-test, t9=3.32, p=0.0089; n=5-6). (M) KCS model simulations show enhancing perceived saliency of the omitted shocks prevents extinction of the conditioned response. Data represented as mean ± S.E.M. * p < 0.05, ** p < 0.01, **** p < 0.0001.

Article Snippet: In a separate group of C57BL/6J mice, AAV5.Ef1a.DIO.hchR2.eYFP (ChR2; UNC vector core) and AAV9.rTH.PI.Cre.SV40 (Addgene; 78) was injected into the VTA and a 200um fiber optic implant was placed into the NAc core.

Techniques: Optogenetics, Injection, Expressing, Blocking Assay