PF-04859989 HCl is a brain-penetrable irreversible inhibitor of kynurenine amino transferase II (KAT II), the enzyme responsible for most of the brain synthesis of kynurenic acid. PF-04859989 HCl has been implicated in several psychiatric and neurological

TC-2153 is a selective inhibitor of striatal-enriched protein tyrosine phosphatase (STEP), exhibiting psychotropic activity and low acute toxicity. This compound not only enhances the expression of brain-derived neurotropic factor (BDNF) in the brain but also reduces the mRNA levels of MAOA and 5-HT1A receptors in the midbrain. Additionally, TC-2153 inhibits 5-HT2A receptor-mediated signaling.

[Glp5,(Me)Phe8,Sar9] Substance P (5-11) (DiMe-C7) is an analogue of Substance P that acts on the neurokinin 1 receptor (NK1R) in rat brain, similarly to Substance P but with a significantly extended duration of action. This compound selectively enhances dopamine metabolism within the mesencephalon and midbrain cortex, increases motor activity, and facilitates the resumption of addictive agent-seeking behavior in rats [1] [2] [3].

Flibanserin (Girosa) is a serotonergic antidepressant used to treat hypoactive sexual desire disorder. Flibanserin has been associated with a low rate of minor serum aminotransferase elevations during treatment but has not been linked to instances of clinically apparent acute liver injury.

RTI-7470-44 is a potent and selective human trace amine-associated receptor 1 (hTAAR1) antagonist (IC50: 8.4 nM) that crosses the blood-brain barrier. RTI-7470-44 increases the spontaneous firing rate of dopaminergic neurons in the ventral tegmental area (VTA) of the midbrain in mice. RTI-7470-44 can be used to study schizophrenia, drug addiction and Parkinson's disease (PD).

LY262691, a selective CCKB antagonist, decreases midbrain dopamine unit activity.

VU6019650 is a potent and selective orthosteric antagonist of M5 mAChR ( IC 50 =36 nM), can be used for opioid use disorder (OUD) relief. VU6019650 can cross blood brain barrier, potentially modulates the mesolimbic dopaminergic reward circuitry. VU6019650 blocks Oxotremorine M iodide induced increases of neuronal firing rates of midbrain dopamine neurons in the ventral tegmental area (VTA) [1] [2] .

PAQ is a neuroprotective agent. It protects dopaminergic neurons from cell death without inhibiting glial cell proliferation in a rat midbrain culture model of Parkinson's disease when used at a concentration of 10 μM. PAQ (25 or 50 mg/kg, twice per day) prevents loss of dopaminergic neurons in the substantia nigra in a mouse model of Parkinson's disease induced by MPTP.