adeno-associated virus vector expressing hM3Dq

Stages

1. 1.
   Targeted DREADD delivery to substantia nigra(library_build)

   This stage creates the engineered primate model by introducing hM3Dq into the target brain region.

   Selection: Establish hM3Dq expression in the unilateral substantia nigra of marmosets.

2. 2.
   In vivo imaging-based expression detection(confirmatory_validation)

   This stage noninvasively verifies that the chemogenetic receptor is expressed in vivo before downstream activation and behavioral interpretation.

   Selection: Detect DREADD expression in vivo by multi-tracer PET imaging.

3. 3.
   Histological confirmation in nigrostriatal dopamine neurons(confirmatory_validation)

   This stage adds cellular confirmation beyond in vivo imaging.

   Selection: Confirm DREADD expression in nigrostriatal dopamine neurons by immunohistochemistry.

4. 4.
   Agonist-triggered activation assessment(functional_characterization)

   This stage tests whether expressed DREADDs are functionally activatable by agonist administration.

   Selection: Assess activation of the substantia nigra following agonist administration.

5. 5.
   Behavioral validation after oral DCZ(confirmatory_validation)

   This stage links chemogenetic activation to an observable behavioral output in freely moving marmosets.

   Selection: Observe contralateral rotation after consuming food containing DCZ and compare with following days without DCZ.

Steps

1. 1.
   Inject AAV vectors expressing hM3Dq into unilateral substantia nigraengineered receptor and delivery harness

   Establish chemogenetic receptor expression in the target brain region.

   Expression must be established before in vivo detection, agonist activation, or behavioral testing can occur.

2. 2.
   Detect DREADD expression in vivo using multi-tracer PET imagingassay method and imaged construct

   Verify in vivo expression of the chemogenetic receptor.

   In vivo expression evidence supports proceeding to functional and behavioral interpretation with greater confidence.

3. 3.
   Confirm expression in nigrostriatal dopamine neurons by immunohistochemistryvalidated construct

   Confirm cellular localization of DREADD expression.

   Histological confirmation follows in vivo detection to strengthen mechanistic interpretation at the cell-type level.

4. 4.
   Assess substantia nigra activation following agonist administrationchemogenetic receptor and agonist

   Test whether agonist administration functionally activates the targeted substantia nigra.

   Functional activation testing is needed after expression confirmation and before attributing behavioral effects to chemogenetic activation.

5. 5.
   Administer DCZ in food and observe contralateral rotation behavioragonist delivery to activate expressed DREADD

   Elicit and measure behavioral consequences of unilateral nigrostriatal activation in freely moving marmosets.

   Behavioral testing is performed after expression and activation evidence to link the engineered perturbation to natural behavior.