spec sheet6 rows
522-054 is a laboratory research compound built in Kelvin Gee's group at the University of California, Irvine to do two opposite things to the hippocampus at once: strengthen α7 nicotinic acetylcholine receptors and block the α5-subunit-containing GABA-A receptors that hold pyramidal cells under constant inhibition. In rats the combination potentiated synapses, lowered the threshold for long-term potentiation, and restored learning and attention that had been disrupted either by scopolamine or by a traumatic brain injury months earlier. The whole published record is two primary papers, both in rats and rat tissue, plus one review that summarises them. No human has been given it and no clinical trial exists.
- Reverses scopolamine-induced attention and memory deficits in rats at a very small injected dose
- Lowers the threshold for hippocampal long-term potentiation, the cellular step the memory results rest on
- Rescues learning and memory in rats three months after a traumatic brain injury, long after the acute window closed
- Repairs depressed basal synaptic transmission in injured hippocampal tissue
- Each half of the mechanism is confirmed by a selective antagonist rather than assumed from the design
Overview
522-054 is a triazolopyridazine derivative, chemically 3-(2,5-difluorophenyl)-6-(N-ethylindol-5-yl)-1,2,4-triazolo[4,3-b]pyridazine, developed by researchers at the University of California, Irvine as a deliberately dual-target molecule [1]. Both α7 nicotinic acetylcholine receptors and α5-containing GABA-A receptors belong to the Cys-loop family of ligand-gated ion channels, and both shape the hippocampal network activity that underlies attention and declarative memory; 522-054 was engineered to enhance the former while blocking the latter from within a single structure [1].
The compound grew out of work showing that combining two separate allosteric modulators, one that inhibits α5 GABA-A receptors and one that enhances α7 nicotinic receptors, produced synergistic long-term potentiation in rat hippocampal slices; 522-054 reproduced that effect as a single agent, and selective antagonists of either receptor blocked its action [1]. In vivo it improved performance in the radial arm maze and sharpened attentional performance in the five-choice serial reaction time task [1]. In a later study using a rat model of traumatic brain injury, applying 522-054 to hippocampal slices reduced deficits in basal synaptic transmission and restored injury-impaired long-term potentiation, and treating animals months after the injury improved fear-based and spatial memory without measurably changing cortical or hippocampal atrophy [2].
522-054 remains an investigational research compound. It has been characterized only in preclinical, largely rodent, studies; it is not an approved drug or a marketed dietary supplement, and no established human safety or clinical data exist. For now it functions mainly as a laboratory tool for probing dual modulation of nicotinic and GABAergic signaling as a strategy for cognitive impairment [1][2].
Mechanism
Two members of the Cys-loop family of -gated ion channels are engaged at once, and they are pushed in opposite directions. At the α7 receptor 522-054 acts as a positive modulator, raising the current an evokes rather than opening the channel itself, with half-maximal enhancement at 1.9 µM [2]. At α5-subunit-containing -A receptors it does the reverse and inhibits them, with half-maximal inhibition at 0.8 µM [2]. A review of modulators places it in the type II class, the group that slows receptor desensitisation as well as lifting the peak response [3].
The reason for pairing those two actions is what each receptor does in the . α5 -A receptors alter network activity by holding CA1 and CA3 pyramidal cells under tonic inhibition; postsynaptic α7 receptors govern the inhibitory interneurons that synchronise those same pyramidal cells, and presynaptic α7 receptors regulate release [1]. Easing the inhibitory brake while strengthening cholinergic drive lowers the threshold for . Applying two separate modulators, one for each receptor, potentiated CA1 excitatory postsynaptic currents into sustained in rat hippocampal slices, and 522-054 reproduced that effect as a single molecule; a selective at either receptor abolished it, which is the evidence that both halves of the design are doing work rather than one carrying the result [1].
In injured tissue the same two actions read as repair rather than enhancement. Bath application at 0.1 µM to slices taken from rats twelve weeks after a fluid percussion brain injury reduced the deficit in basal transmission and rescued the maintenance phase of at the Schaffer collateral to CA1 ; the first ten minutes of potentiation were unchanged by either the injury or the drug [2]. One thing the mechanism has never been given is a selectivity check. No published counter-screen against α1, α2 or α3 -A receptors, or against subtypes other than α7, has been located, so the compound's cleanliness is a design intention rather than a measured fact.
receptor fingerprint
α7 receptorPositive allosteric modulator; lifts the current an agonist evokes rather than opening the channel itself, and a review of the field places it in the type II class that also slows desensitisation
α5-subunit-containing -A receptorNegative allosteric modulator; inhibits the tonic inhibitory current these receptors impose on CA1 and CA3 pyramidal cells
Basal transmission in injured Restores the input to output relationship depressed by traumatic brain injury, measured in slices from rats twelve weeks after a fluid percussion injury at 0.1 uM in the bath
Hippocampal (Schaffer collateral to CA1)Drops the induction threshold; sustained potentiation of CA1 excitatory postsynaptic currents was measured directly in rat slices and was abolished by a selective antagonist at either receptor
Other -A subtypes (α1, α2, α3) and non-α7 subtypesNot measured. No counter-screen has been published, so selectivity here is inferred from the design brief rather than demonstrated; the two receptors above are the only characterised actions
Dosingtypical ranges, not medical advice
interested in protocols and clinical dosages? make an account to see them! ^_^
Safetyrisks and cautions, not medical advice
Nothing is known about 522-054 in people, because no published study has given it to one. It has no approval anywhere, no registered clinical trial, and no published pharmacokinetic, tolerability or toxicology data in any species. Everything below is either an observation from rat work or an inference from what its two receptors are known to do, and an inference is not a safety record.
The specific concern named by the investigators themselves is seizure threshold. Blocking α5 GABA-A receptors removes inhibition, and negative allosteric modulators at GABA-A receptors are used deliberately as chemoconvulsants in rodent seizure models; the traumatic brain injury study raised the possibility that 522-054 could increase the risk of post-traumatic epilepsy, and stated plainly that seizure threshold changes and signs of epilepsy were not assessed [2]. That question is open rather than answered.
The wider drug class has a discouraging human record, and the compounds carrying it are not this one. Two other α5 GABA-A negative allosteric modulators reached Phase 1 trials: α5IA was discontinued over hepatotoxicity concerns, and MRK-016 produced adverse effects in older subjects [2]. Neither result transfers to 522-054 automatically, and neither can be waved away either.
What tolerability signal exists is thin and indirect. Rats given 0.03 mg/kg by intraperitoneal injection before behavioural training gained weight normally across the study, with no difference between treated and untreated groups [2]. Only male rats have ever received it; the same paper flagged the absence of female animals as a limitation and noted that responses to α5 GABA-A modulators are known to differ by sex [2]. There is no oral data, no repeat-dose data, and no interaction data of any kind.
History
522-054 is a triazolopyridazine cognitive-enhancer candidate that emerged from the University of California, Irvine pharmacology group of Kelvin W. Gee, with Derk J. Hogenkamp and Timothy Johnstone among the co-inventors on associated patents. It was engineered as a single molecule with dual allosteric activity, acting as a positive allosteric modulator of the alpha7 nicotinic acetylcholine receptor while simultaneously inhibiting alpha5-subunit GABA-A receptors, a combination the group showed could synergistically enhance hippocampal long-term potentiation.
Preclinical characterization, reported from around 2010 onward, demonstrated procognitive effects in attentional and memory tasks such as the five-choice serial reaction time test and radial-arm maze, and later work extended it to models of chronic traumatic brain injury. It remains an experimental research compound with no clinical development or approval.
Subjective profileweighing the evidence above
Strictly a laboratory compound. The dual alpha7 nicotinic and alpha5 GABA-A design is genuinely clever and the rodent memory rescue is striking, but there is no human data at all, and alpha5 GABA-A modulation is dose-sensitive enough that guessing would be reckless.
Resources
This entry is here for reference.
Research
- 2011first citedAllosteric modulation of related ligand-gated ion channels synergistically induces long-term po…
- 2024most recentEnhancing cognitive recovery in chronic traumatic brain injury through simultaneous allosteric…
- 1.Allosteric modulation of related ligand-gated ion channels synergistically induces long-term potentiation in the hippocampus and enhances cognition
- 2.Enhancing cognitive recovery in chronic traumatic brain injury through simultaneous allosteric modulation of α7 nicotinic acetylcholine and α5 GABA-A receptors
- 3.Effects of neuronal nicotinic acetylcholine receptor allosteric modulators in animal behavior studies
3 listed here; entry last updated August 2026
Reviews
My notesprivate to this device
FAQ
What does 522-054 actually do?
It does two things at once, in opposite directions. It strengthens the response of α7 nicotinic acetylcholine receptors and it inhibits α5-subunit-containing GABA-A receptors. In the hippocampus those two changes push the same way: more excitatory cholinergic drive and less of the constant background inhibition, which makes long-term potentiation easier to trigger.
Has anyone taken it?
No published study has given 522-054 to a human. There is no registered clinical trial, no Phase 1 result, and no pharmacokinetic data in any species. The whole record is rats, rat brain slices, and receptors expressed in frog oocytes.
Why does it look so potent in animals?
Injected doses that work in rats are unusually small, around 0.03 mg/kg into the abdomen. The receptor numbers are not small in the same way: half-maximal enhancement of the α7 receptor sits at 1.9 µM and half-maximal inhibition of the α5 GABA-A receptor at 0.8 µM, which is ordinary micromolar territory. No published work resolves that gap, and without pharmacokinetic data there is no way to check whether brain levels ever approach those concentrations.
Is it dangerous?
Unknown, and the unknown has a specific shape. Removing α5 GABA-A inhibition is the same direction of change that chemoconvulsants exploit, and the traumatic brain injury study said outright that it did not measure seizure threshold or look for epilepsy developing. Two other α5 negative allosteric modulators that reached Phase 1 in humans ran into trouble, one over liver toxicity and one over adverse effects in older subjects, though neither of those is this molecule.
Is the rodent memory effect real enhancement?
Mostly it is rescue rather than enhancement. The radial arm maze and five-choice attention results are recoveries of performance that scopolamine had deliberately knocked down, and the brain injury results are recoveries in injured animals. Whether a healthy animal gains anything from it is a separate question the literature has barely touched, and whether a healthy person would is untouched entirely.
Is there a dose?
None exists for a person. The rodent figure is 0.03 mg/kg by intraperitoneal injection about thirty minutes before a learning task, and it was chosen because it was optimal against scopolamine, not because it maps onto anything human. No oral route has been tested, the vehicle used is a solvent blend rather than water, and nobody has published what repeat dosing does.
Limitations of the evidence
- Characterized only in preclinical rodent studies, with no human safety data
- Long-term effects of combined α7 nicotinic and α5 GABA-A modulation in humans are unknown
- Every published in vivo result comes from male rats; no female animal has ever been dosed with it
- Blocking α5 GABA-A receptors is the mechanism that could lower seizure threshold, and seizure threshold has never been measured for this compound
- Selectivity is unmeasured; no counter-screen against other GABA-A or nicotinic subtypes has been published
- Pharmacokinetics are unpublished in every species, so there is no half-life, no oral figure and no brain exposure number
- Rodent gains are mostly recovery from a deficit that was deliberately induced, not enhancement of a healthy animal
- Both primary papers carry the chemists who made the compound as co-authors, so no fully independent group has tested it
- Behaviour recovered in injured rats without any reduction in cortical or hippocampal atrophy, so it compensates rather than repairs tissue
Notes and cautions
- Not an approved drug or a marketed supplement