Dear Erowid Readers: We're a small nonprofit that runs the top drug information website in the world. We have only 4 staff but serve 12 million users, and have costs like any big website: servers, power, office space, programs, and staff. To protect our independence, we don't run ads or take government funds. If everyone reading this gave $3, our fundraising would be done today. If Erowid is useful to you, take a minute to keep it online and ad-free another year!
Donate by Bitcoin

Erowid References Database

Lindefors N, Barati S, O'Connor WT. 
“Differential effects of single and repeated ketamine administration on dopamine, serotonin and GABA transmission in rat medial prefrontal cortex”. 
Brain Res. 1997 Jun 28;759(2):205-12.
Abstract
Cognitive functions regulated by the prefrontal cortex are sensitive to changes in dopaminergic and serotoninergic transmission. The non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist ketamine influences dopaminergic transmission and induces psychotic symptoms in normal and schizophrenic individuals. This study examined the effect of single and repeated ketamine (25 mg/kg, i.p.) administration on extracellular levels of dopamine, GABA and the serotonin metabolite 5-hydroxyindoleacetic (5-HIAA) acid in the medial prefrontal cortex using in vivo microdialysis in conscious rat. In line with earlier studies, we observed a transient five-fold increase in dopamine release following single ketamine administration in drug naive animals. However, we also observed a two-fold increase in basal dopamine levels and an almost complete attenuation of the ketamine-induced increase in dopamine release in animals pre-treated with ketamine once daily for 7 days. Extracellular 5-HIAA levels were increased by ketamine in both drug naive and even more enhanced in ketamine-pre-treated animals but without a change in basal 5-HIAA levels. GABA levels were unaffected by either single or repeated ketamine administration. We demonstrate evidence for a differential effect of single and repeated ketamine administration on dopamine, serotonin and GABA transmission in the medial prefrontal cortex. We provide new evidence for a complex adaptation of neurotransmission following repeated NMDA receptor blockade whereby in the presence of increased basal dopamine levels the ketamine-induced increase in dopamine is attenuated and the increase in 5-HIAA is enhanced. It appears from our results that ketamine pre-treatment reduces the dynamics of dopaminergic transmission in the prefrontal cortex and may possibly alter the balance between dopamine and serotonin transmission.
Submit Comment
[ Cite HTML ]



Erowid.org Plants & Drugs Mind & Spirit Freedom & Law Arts & Sciences Search About Erowid and Feedback Library & Bookstore Copyrights Memberships noref