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Abstract Aim The therapeutic potential of N‐methyl‐D‐aspartate glutamate receptor (NMDAR) antagonists, particularly ketamine, in mood disorders, is linked to their modulation of dopamine dynamics in the medial prefrontal cortex (mPFC). However, conflicting effects of distinct NMDAR antagonists, like ketamine and phencyclidine, on mPFC dopamine levels stem from variances in their receptor affinity profiles. This study investigates the impact of intermittent subchronic administration of an NMDAR antagonist on dopamine synthesis capacity and responsiveness within the mPFC, focusing on Dizocilpine (MK‐801), a highly selective NMDAR antagonist. Methods In vivo microdialysis and high‐performance liquid chromatography assessed extracellular dopamine levels in the mPFC following subchronic MK‐801 treatment. Locomotor activity was measured using a computed video tracking system. Results Intermittent subchronic MK‐801 administration, followed by a 24‐h withdrawal, preserved both dopamine synthesis capacity and responsiveness to MK‐801 challenge in the mPFC. However, altered locomotor activity was observed, deviating from previous findings indicating impaired dopamine synthesis and responsiveness in the mPFC with twice‐daily subchronic NMDAR antagonist treatment. Conclusion These findings offer crucial biochemical insights into the diverse impacts of NMDAR antagonists on dopamine dynamics and the distinct therapeutic mechanisms associated with ketamine in depression treatment. However, further investigation is imperative to pinpoint potential inconsistencies stemming from variances in drug type, dosage, or administration frequency.

We examined the effects of three benzofurans [1-(Benzofuran-5-yl)-N-methylpropan-2 -amine (5-MAPB), 1-(Benzofuran-2-yl)-N-methylpropan-2-amine (2-MAPB), and 1-(Benzofuran-5-yl)- N-ethylpropan-2-amine (5-EAPB)] on the extracellular monoamine level in mouse corpus striatum by the microdialysis method and compared them with the effects of psychoactive 3,4-Methylenedioxymethamphetamine (MDMA). The effects of benzofurans on the extracellular monoamine level were qualitatively analogous to that of MDMA, with an increase in serotonin (5-HT) level exceeding dopamine (DA) level. The effects of 2-MAPB and 5-EAPB were almost the same as the effect of MDMA. However, 5-MAPB strongly increased extracellular monoamine level than MDMA. These differences in the potency appear to have a structure-activity relationship. The administration of 5-MAPB (1.6 × 10-4 mol/kg B.W.) resulted in the death of two-thirds of the mice. The same dose of MDMA did not cause any deaths. The administration of 5-MAPB (1.6 × 10-4 mol/kg B.W.) produced a 3.41°C ± 0.28°C rise in rectal temperature after 1 hr, whereas the administration of MDMA (1.6 × 10-4 mol/kg B.W.) produced an approximate 1.85°C ± 0.26°C rise. These results suggest that benzofurans have 5-HT toxicity similar to MDMA, and 5-MAPB has a higher risk of lethal intoxication than MDMA. Furthermore, 5-APB, the metabolic product of 5-MAPB demethylation, may be involved in the acute 5-HT toxicity and may cause lethal intoxication in mice. [ABSTRACT FROM AUTHOR]