Three isomers of the new psychoactive substance 3-fluorophenmetrazine (2-FPM, 3-FPM, and 4-FPM) inhibit dopamine and norepinephrine transporters with potencies comparable to cocaine (IC50 values below 2.5 μM) but show much weaker effects at the serotonin transporter (IC50 values above 80 μM). They also induce efflux of monoamines via all three transporters, an effect enhanced by the ionophore monensin. These compounds act as monoamine releasers with marked potency at catecholamine transporters implicated in abuse and addiction.
Ketamine triggers a rapid increase in histone H3 Ser10 phosphorylation in mouse hippocampal neurons and in the mouse hippocampus, an effect driven by JNK activation. Blocking JNK with SP600125 reversed this epigenetic change and reduced ketamine-induced hyperlocomotion and cognitive deficits. Multi-omics analysis 30 minutes after ketamine identified 262 differentially expressed genes, including MAP3K9, enriched in MAPK signaling and neuroactive ligand-receptor pathways, and 165 differentially accessible chromatin regions, with CTCF as a potential regulator. The findings suggest that JNK-mediated H3S10 phosphorylation links ketamine exposure to psychosis-like behaviors, offering a mechanistic connection between stress-sensitive signaling, rapid chromatin remodeling, and transcriptional reprogramming.