Dr. Grey AI

Coluracetam

Coluracetam is a synthetic racetam nootropic originally developed in Japan for Alzheimer's disease (failed trials). Its unique mechanism involves enhancing High Affinity Choline Uptake (HACU) - the rate-limiting step in acetylcholine synthesis. Unlike piracetam, it specifically targets choline transport rather than general cognitive enhancement. Phase 2 trials for depression showed no significant benefit over placebo. Very limited evidence - primarily animal studies showing it can preserve choline uptake when impaired. Not proven effective for any use in humans.

Quick Answer

What it is

Coluracetam is a synthetic racetam nootropic originally developed in Japan for Alzheimer's disease (failed trials). Its unique mechanism involves enhancing High Affinity Choline Uptake (HACU) - the rate-limiting step in acetylcholine synthesis.

Key findings

  • Grade D: High-Affinity Choline Uptake (HACU)
  • Grade D: Learning and Memory (Cholinergic Deficit Models)
  • Grade D: Acetylcholine Synthesis and Release

Safety

No specific caution or interaction language was detected in the current summary/outcome notes.

ℹ️ Quick Facts: Coluracetam

Quick Facts: Coluracetam

  • Best Evidence:Grade D
  • Conditions Studied:3
  • Research Outcomes:6
  • Key Effect:Age-Associated Memory Impairment and Cognitive Decline (AAMCD)
Outcomes by grade:
A0
B0
C0
D6
3 conditions · 6 outcomes

Detailed Outcomes

|
D
High-Affinity Choline Uptake (HACU)
In rodent models with pharmacologically impaired cholinergic function (AF64A and ethylcholine aziridinium), coluracetam (MKC-231) consistently preserved and enhanced high-affinity choline uptake, increasing Vmax of HACU and Bmax of HC-3 binding approximately 1.6-1.7 fold. Effects appear specific to impaired HACU rather than enhancing normal function.
moderate↑Improves
D
Acetylcholine Synthesis and Release
In AF64A-treated rats with reduced hippocampal acetylcholine, coluracetam significantly reversed decreases in ACh synthesis and release. The effect is mediated through enhanced choline transport rather than acetylcholinesterase inhibition, distinguishing it mechanistically from donepezil-class drugs.
moderate↑Improves
D
Cholinergic Neuroprotection (PCP Model)
In a single rat study, subsequent exposure to coluracetam antagonized phencyclidine (PCP)-induced behavioral deficits and reduction in septal cholinergic neurons, suggesting potential neuroprotective properties for cholinergic pathways under neurotoxic stress.
small↑Improves
D
Learning and Memory (Cholinergic Deficit Models)
In AF64A-treated rats and mice with cholinergic deficits, oral coluracetam (1-10 mg/kg) significantly improved water maze learning and working memory deficits. Repeated administration produced long-lasting cognitive improvement persisting 24-72 hours after the last dose, suggesting durable changes to choline transporter regulation. No cognitive enhancement was observed in normal (non-impaired) animals.
moderate↑Improves
D
Alzheimer's Disease Symptoms
Mitsubishi Tanabe Pharma conducted a Phase 2a clinical trial for Alzheimer's disease. The trial failed to meet efficacy endpoints and development was discontinued for this indication. Despite a plausible HACU-based mechanism, human evidence does not support benefit in Alzheimer's disease.
1 study
small↓Improves
D
Depression and Anxiety Symptoms
BrainCells Inc. conducted a Phase 2 clinical trial for major depressive disorder with comorbid generalized anxiety disorder. Primary endpoints were not met — no significant benefit over placebo was demonstrated. Development for this indication was discontinued.
1 study
small↓Improves

Research Citations (10)

MKC-231, a choline-uptake enhancer: (1) long-lasting cognitive improvement after repeated administration in AF64A-treated rats
(2008)
PMID: 18461272
MKC-231, a choline uptake enhancer: (2) Effect on synthesis and release of acetylcholine in AF64A-treated rats
(2008)
PMID: 18446264
MKC-231, a choline uptake enhancer: (3) Mode of action of MKC-231 in the enhancement of high-affinity choline uptake
(2008)
PMID: 18461273
Subsequent exposure to the choline uptake enhancer MKC-231 antagonizes phencyclidine-induced behavioral deficits and reduction in septal cholinergic neurons in rats
(2007)
PMID: 17467960
Effect of MKC-231 on spatial learning retention
(1999)
PMID: 10400478
MKC-231, a choline uptake enhancer, activates the cholinergic nervous system
(1997)
PMID: 9225290
Effects of MKC-231 on high-affinity choline uptake in the hippocampus
(1996)
PMID: 8799197
Effect of the novel high affinity choline uptake enhancer 2-(2-oxopyrrolidin-1-yl)-N-(2,3-dimethyl-5,6,7,8-tetrahydrofuro[2,3-b]quinolin-4-yl)acetoamide on deficits of water maze learning in rats
(1996)
PMID: 8740080
MKC-231, a choline uptake enhancer: effect on recovery from AF64A-induced learning impairment
(1994)
PMID: 8825012
MKC-231, a choline uptake enhancer, ameliorates working memory deficits and decreased hippocampal acetylcholine induced by ethylcholine aziridinium ion in mice
(1994)
PMID: 7710736

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