Study Code: NDNS-PD-001
Hypothesis: Degeneration of non-dopaminergic neurotransmitter systems (noradrenergic, serotonergic, cholinergic, GABAergic) is an upstream driver of Parkinson's disease progression, occurring independently of and potentially preceding dopaminergic loss.
Phase: Preclinical + Clinical Translation
Objective: Validate selective vulnerability of non-dopaminergic neurons to alpha-synuclein toxicity
Models:
- iPSC-derived neurons from:
- PD patients with LRRK2 G2019S mutation (n=3)
- PD patients with idiopathic PD (n=3)
- Healthy controls (n=3)
- Cell types: locus coeruleus noradrenergic, dorsal raphe serotonergic, pedunculopontine cholinergic, cortical GABAergic
Endpoints:
- Neuronal survival after α-syn oligomer exposure (MTT, Live/Dead)
- Neurotransmitter synthesis enzymes (TH, TPH2, ChAT, GAD67)
- Calcium homeostasis (Fura-2 imaging)
- Mitochondrial function (Seahorse XF)
Objective: Map functional interactions between non-dopaminergic systems
Models:
- Co-culture systems: LC + DRN; PPN + NBM; LC + PPN
- Optogenetic manipulation of each system
Endpoints:
- Neurotransmitter release (norepinephrine, serotonin, acetylcholine, GABA)
- Network activity (multi-electrode array)
- Calcium signaling synchronization
Objective: Determine if α-syn pathology directly targets non-dopaminergic nuclei
Models:
- Primary neurons from LC, DRN, PPN
- Exposure to α-syn pre-formed fibrils (PFF)
Endpoints:
- Phosphorylation (pSer129) and aggregation
- Neurotransmitter enzyme expression
- Axonal transport (live cell imaging)
Objective: Validate non-dopaminergic degeneration in established PD models
Models:
Endpoints:
- Neurotransmitter levels (HPLC: NE, 5-HT, ACh, GABA)
- Neuron counts (TH, TPH2, ChAT, GAD67 IHC)
- PET imaging (VMAT2, 5-HT2A, nicotinic ligands)
Objective: Test combined neurotransmitter modulation
Models:
- AAV-α-syn injected rats with LC, DRN, PPN targeting
- Pharmacological intervention at 3 months post-injection
Interventions:
- Noradrenergic: Atomoxetine (NET inhibitor) 10 mg/kg
- Serotonergic: 5-HT2A antagonist (M100907) 1 mg/kg
- Cholinergic: Donepezil 3 mg/kg
- Combination: All three
Endpoints:
- Motor behavior (cylinder, stepping, gait analysis)
- Non-motor (olfaction, nesting, sucrose preference)
- Neurotransmitter levels
- Neuronal survival
Objective: Test if early intervention preserves non-dopaminergic systems
Models:
- M83 mice (starting at 3 months, pre-symptomatic)
Interventions:
- AAV-DREADD expression in LC for chemogenetic activation
- Antioxidant treatment ( Nacetylcysteine 150 mg/kg)
Endpoints:
- Non-dopaminergic neuron survival
- Neurotransmitter levels
- Progression to symptomatic phase
Objective: Identify CSF and imaging biomarkers for non-dopaminergic degeneration
Cohorts:
- De novo PD patients (n=50)
- PD with RBD (n=30)
- PD-MCI (n=30)
- Healthy controls (n=30)
Endpoints:
- CSF: 5-HIAA, MHPG, ACh, GABA
- Serum: Neurofilament light chain (NfL)
- PET: VMAT2, 5-HT2A, nicotinic, GABA-A
- MRI: Neuromelanin-sensitive imaging (LC, raphe)
Objective: Test multi-target intervention in PD patients
Design: Randomized, double-blind, placebo-controlled
Cohort: Early PD (H&Y 1-2), with non-motor symptoms (n=120)
Interventions (12 weeks):
- Arm 1: Atomoxetine 40mg daily
- Arm 2: Donepezil 10mg daily
- Arm 3: Combination
- Arm 4: Placebo
Endpoints:
- Primary: MDS-UPDRS Part III (motor), Non-motor symptoms (MDS-NMS)
- Secondary: Attention (Stroop), Executive (Trail Making), CSF biomarkers
- Safety: Adverse events, ECG
Objective: Map non-dopaminergic degeneration trajectory
Cohort: Newly diagnosed PD (n=200), follow 5 years
Endpoints:
- Annual PET imaging (all receptor systems)
- CSF neurotransmitter metabolites
- Clinical assessment (motor and non-motor)
- Progression to dementia, falls
| Endpoint |
Method |
Timepoint |
| Non-dopaminergic neuron survival |
IHC (TH, TPH2, ChAT) |
6 months |
| Neurotransmitter levels |
HPLC |
6 months |
| Motor behavior |
cylinder, stepping |
3, 6 months |
| Non-motor behavior |
OFT, nesting |
3, 6 months |
| Endpoint |
Method |
Timepoint |
| Network activity |
MEA |
2 weeks |
| Biomarkers |
CSF/serum |
Baseline, 6 months |
| PET imaging |
VMAT2, 5-HT2A |
Baseline, 6 months |
| Clinical outcomes |
MDS-UPDRS |
Every 3 months |
- Sample size: Power 80% to detect 30% difference (α=0.05)
- Repeated measures ANOVA for time-course
- Linear mixed models for longitudinal data
- Correction for multiple comparisons (Bonferroni)
- Animal welfare: 3R principles, ARRIVE guidelines
- Human subjects: IRB approval, informed consent
- Vulnerable populations: Careful inclusion criteria for cognitive impairment
- Phase 1: 12 months
- Phase 2: 18 months
- Phase 3: 36 months (biomarker) + 24 months (clinical trial)
- Total: 5 years
- Phase 1: $500K
- Phase 2: $1.2M
- Phase 3: $3.5M
- Total: $5.2M