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S P Berger

2 papers in the library · 19 citations · publishing 1996-2015

Papers

Neuropharmacological characterization of local ibogaine effects on dopamine release.

Journal of neural transmission (Vienna, Austria : 1996) January 1, 1996 M S Reid, K Hsu, K H Souza et al. 19 citations

In rats, ibogaine applied directly to the nucleus accumbens or striatum via microdialysis had a biphasic effect on extracellular dopamine: lower doses (10⁻⁶ M–10⁻⁴ M) decreased dopamine levels, while higher doses (5×10⁻⁴ M–10⁻³ M) increased them. The dopamine metabolite DOPAC was unaffected. Co-administration with naloxone or norbinaltorphimine blocked the dopamine decrease, suggesting involvement of kappa opioid receptors. The stimulatory effect at high doses was calcium-independent, not blocked by tetrodotoxin, but reduced by cocaine, reserpine, or alpha-methyl-para-tyrosine pretreatment. In striatal synaptosomes, ibogaine and harmaline inhibited dopamine uptake dose-dependently, indicating the stimulatory effect involves the dopamine transporter.

Inducible Nitric Oxide Inhibitors Block NMDA Antagonist-Stimulated Motoric Behaviors and Medial Prefrontal Cortical Glutamate Efflux.

Frontiers in pharmacology January 1, 2015 Hadley C Bergstrom, Altaf S Darvesh, S P Berger

Inhibiting inducible nitric oxide synthase (iNOS) with aminoguanidine (AG) or (-)-epigallocatechin-3-gallate (EGCG) reduces the motor and glutamate-releasing effects of NMDA-antagonist stimulants like dizocilpine (MK-801) and phencyclidine (PCP) in adult male rats. AG and EGCG dose-dependently attenuated the locomotor and ataxic properties of MK-801 and PCP, but not those of cocaine, indicating specificity to NMDA antagonism. Both agents also normalized MK-801-stimulated glutamate efflux in the medial prefrontal cortex. These results suggest that EGCG-like polyphenols found in green tea and chocolate may protect against the adverse behavioral and cortical glutamate effects of NMDA antagonists, which have been proposed as treatments for schizophrenia.