Source Paper
Source Paper
Alexxai V. Kravitz, Benjamin S. Freeze, Philip R. L. Parker, Kenneth Kay, Myo T. Thwin et al.
Nature • 2010
Objective: To directly activate basal ganglia circuitry using optogenetic control of direct- and indirect-pathway medium spiny projection neurons (MSNs) and measure effects on motor behavior including freezing, bradykinesia, and locomotor initiation
This is a Optogenetic Activation of Indirect-Pathway MSNs protocol using mouse as the model organism. The procedure involves 8 procedural steps, 2 equipment items, 1 materials. Extracted from a 2010 paper published in Nature.
Model and subjects
mouse • D1-Cre and D2-Cre BAC transgenic mice • Not specified • Not specified • Not specified • Not specified
Study window
Estimated timing pending
Core workflow
Viral vector preparation and injection • Stereotaxic injection of viral vectors • Expression period
Primary readouts
Key equipment and reagents
Verified items
0
Direct vendor links
0
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Prepare Cre-dependent viral expression vectors containing channelrhodopsin-2 for injection into striatum
Note: Separate viral preparations for D1-Cre and D2-Cre transgenic mice to target direct- and indirect-pathway MSNs respectively
“Cre-dependent viral expression of channelrhodopsin-2 in the striatum of D1-Cre and D2-Cre BAC transgenic mice”
Inject Cre-dependent channelrhodopsin-2 viral vectors into the striatum of transgenic mice
Note: Bilateral injections to target both hemispheres for subsequent bilateral excitation
“Cre-dependent viral expression of channelrhodopsin-2 in the striatum of D1-Cre and D2-Cre BAC transgenic mice”
Allow time for viral expression of channelrhodopsin-2 in target neurons
Note: Duration not specified in provided text
“Cre-dependent viral expression of channelrhodopsin-2 in the striatum”
Deliver light stimulation to activate channelrhodopsin-2 expressing indirect-pathway MSNs bilaterally and measure resulting motor behavior
Note: Bilateral excitation used to elicit parkinsonian state
“Bilateral excitation of indirect-pathway MSNs elicited a parkinsonian state, distinguished by increased freezing, bradykinesia, and decreased locomotor initiations”
Measure and record motor behaviors including freezing, bradykinesia, and locomotor initiation during optogenetic stimulation
Note: Parkinsonian phenotype characterized by increased freezing, bradykinesia, and decreased locomotor initiations
“Bilateral excitation of indirect-pathway MSNs elicited a parkinsonian state, distinguished by increased freezing, bradykinesia, and decreased locomotor initiations”
Deliver light stimulation to activate channelrhodopsin-2 expressing direct-pathway MSNs and measure resulting motor behavior
Note: Opposite effects to indirect-pathway activation
“activation of direct-pathway MSNs reduced freezing and increased locomotion”
Measure and record motor behaviors during optogenetic stimulation of direct-pathway MSNs
Note: Direct pathway activation produces reduced freezing and increased locomotion
“activation of direct-pathway MSNs reduced freezing and increased locomotion”
Perform optogenetic stimulation of direct-pathway MSNs in a mouse model of Parkinson's disease and assess rescue of motor deficits
Note: Direct pathway activation completely rescued deficits in freezing, bradykinesia, and locomotor initiation
“In a mouse model of Parkinson's disease, direct pathway activation completely rescued deficits in freezing, bradykinesia, and locomotor initiation”
This section explains what the experiment is doing, which readouts matter, what the data artifacts usually look like, and how the analysis should flow from raw capture to reported result.
To directly activate basal ganglia circuitry using optogenetic control of direct- and indirect-pathway medium spiny projection neurons (MSNs) and measure effects on motor behavior including freezing, bradykinesia, and locomotor initiation
Objective
To directly activate basal ganglia circuitry using optogenetic control of direct- and indirect-pathway medium spiny projection neurons (MSNs) and measure effects on motor behavior including freezing, bradykinesia, and locomotor initiation
Subjects
From papermouse • D1-Cre and D2-Cre BAC transgenic mice • Not specified • Not specified • Not specified
Sample count
From paperNot specified
Cohort notes
From paperTwo transgenic mouse lines used: D1-Cre for direct-pathway MSNs and D2-Cre for indirect-pathway MSNs
Viral vector preparation and injection (Not specified)
Stereotaxic injection of viral vectors (Not specified)
Expression period (Not specified)
Optogenetic stimulation of indirect-pathway MSNs (Not specified)
Freezing behavior (increased with indirect-pathway activation, decreased with direct-pathway activation)
From paperNot specified in provided text
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
Bradykinesia (increased with indirect-pathway activation, decreased with direct-pathway activation)
From paperNot specified in provided text
Artifact type
Endpoint measurements summarized by group or timepoint
Comparison focus
Compare endpoint magnitude between groups, timepoints, or both
Locomotor initiation (decreased with indirect-pathway activation, increased with direct-pathway activation)
From paperNot specified in provided text
Artifact type
Longitudinal gait metrics and per-animal performance tables
Comparison focus
Compare recovery trajectory across post-injury timepoints and treatment conditions
Overall locomotion (increased with direct-pathway activation)
From paperNot specified in provided text
Artifact type
Longitudinal gait metrics and per-animal performance tables
Comparison focus
Compare recovery trajectory across post-injury timepoints and treatment conditions
Freezing behavior (increased with indirect-pathway activation, decreased with direct-pathway activation)
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
Bradykinesia (increased with indirect-pathway activation, decreased with direct-pathway activation)
From paperRaw artifact
Per-sample or per-animal endpoint measurements collected during the experiment
Processed artifact
Structured table with cleaned measurements ready for comparison
Final reported form
Summary statistics and between-group or across-timepoint comparisons
Locomotor initiation (decreased with indirect-pathway activation, increased with direct-pathway activation)
From paperRaw artifact
Per-run gait capture with paw placement, timing, and stride features for each animal
Processed artifact
Cleaned gait metrics table and recovery trend summary across timepoints
Final reported form
Group comparisons of gait indices, stride metrics, or recovery curves
Overall locomotion (increased with direct-pathway activation)
From paperRaw artifact
Per-run gait capture with paw placement, timing, and stride features for each animal
Processed artifact
Cleaned gait metrics table and recovery trend summary across timepoints
Final reported form
Group comparisons of gait indices, stride metrics, or recovery curves
Acquisition
Collect raw experimental outputs with enough metadata to preserve sample identity, condition, and timing.
Preprocessing / cleaning
Not specified in provided text
Scoring or quantification
Quantify the primary readouts for this experiment: Freezing behavior (increased with indirect-pathway activation, decreased with direct-pathway activation); Bradykinesia (increased with indirect-pathway activation, decreased with direct-pathway activation); Locomotor initiation (decreased with indirect-pathway activation, increased with direct-pathway activation); Overall locomotion (increased with direct-pathway activation).
Statistical comparison
Statistical method not yet structured for this page.
Reporting output
Report representative outputs alongside summary comparisons for Freezing behavior (increased with indirect-pathway activation, decreased with direct-pathway activation), Bradykinesia (increased with indirect-pathway activation, decreased with direct-pathway activation), Locomotor initiation (decreased with indirect-pathway activation, increased with direct-pathway activation), Overall locomotion (increased with direct-pathway activation).
Source links and direct wording from the methods section for validation and deeper review.
Citation
Alexxai V. Kravitz et al. (2010). Regulation of parkinsonian motor behaviours by optogenetic control of basal ganglia circuitry. Nature
Viral vector preparation and injection • Protocol step
“Cre-dependent viral expression of channelrhodopsin-2 in the striatum of D1-Cre and D2-Cre BAC transgenic mice”
Expression period • Protocol step
“Cre-dependent viral expression of channelrhodopsin-2 in the striatum”
Optogenetic stimulation of indirect-pathway MSNs • Protocol step
“Bilateral excitation of indirect-pathway MSNs elicited a parkinsonian state, distinguished by increased freezing, bradykinesia, and decreased locomotor initiations”
Optogenetic stimulation of direct-pathway MSNs • Protocol step
“activation of direct-pathway MSNs reduced freezing and increased locomotion”
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Current status surfaces were computed from experiment data updated Feb 28, 2026.
Source access
Jump back into the original paper or the methods evidence section when you need exact wording, exclusions, or method-specific caveats.
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Steps
8
Evidence Quotes
5
Protocol Items
3
Linked Products
0
Canonical Sync
Pending
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Steps
8
Evidence
5
Specific Products
0/0
Canonical Sync
Pending
What this score means
The verification score reflects evidence coverage, subject detail, paper provenance, step depth, and whether linked products resolve to specific item pages instead of generic searches.
Computed from the current experiment record updated Feb 28, 2026.
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