Cortical ablation and drug-induced changes in striatal ascorbic acid oxidation and behavior in the rat

• Published in: Pharmacology, biochemistry and behavior biochemistry and behavior, 1995, Vol.50 (1), p.1-7
• Main Authors: Miele, Maddalena, Enrico, Paolo, Esposito, Giovanni, Fresu, Luigia, Migheli, Rossana, De Natale, Guglielmo, Desole, Maria S.
• Format: Article
• Language: English
• Subjects: 3,4-Dihydroxyphenylacetic Acid - metabolism; Animals; Apomorphine - pharmacology; Ascorbic Acid - metabolism; Ascorbic acid oxidation; Behavior Apomorphine; Behavior, Animal - drug effects; Biological and medical sciences; Catecholaminergic system; Cerebral Cortex - physiology; Corticostriatal glutamatergic pathways; Dehydroascorbic Acid - metabolism; Dopamine - metabolism; Glutamic Acid - pharmacology; Male; Medical sciences; Motor Activity - drug effects; Neostriatum - drug effects; Neostriatum - metabolism; Neuropharmacology; Neurotransmitters. Neurotransmission. Receptors; Oxidation-Reduction; Pharmacology. Drug treatments; Rat; Rats; Rats, Wistar; Scopolamine; Scopolamine - pharmacology; Stereotyped Behavior - drug effects; Striatal dopamine turnover; Synaptosomes - drug effects; Synaptosomes - metabolism
• ISSN: 0091-3057; 1873-5177
• DOI: 10.1016/0091-3057(94)00209-2

Rats whose frontoparietal cortex had been bilaterally ablated were allowed 21 days for recovery and then treated with apomorphine (APO), 1 mg/kg SC or scopolamine (SCOP), 0.6 mg/kg SC. Soon after a behavioral test, dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), ascorbic acid (AA), and dehydroascorbic acid (DHAA) levels were determined by HPLC/EC in striatal synaptosomes (left side) and whole striatum (right side). SCOP behavioural effects were attenuated by cortical ablation, while those of APO were affected to a lesser extent. In the striatum of unoperated and sham-operated rats DHAA contents and DHAA/AA ratio resulted increased after drugs administration. No change in AA oxidation was observed in the striatum of ablated rats. In the synaptosomes of unoperated and sham-operated rats both drugs led to a decrease in DHAA contents and DHAA/AA ratio. In unoperated and sham-operated rats APO and SCOP caused a decrease of the DOPAC/DA ratio in the whole striatum and striatal synaptosmes. In ablated rats APO caused a decrease of DOPAC/DA ratio in the whole striatum and synaptosomes, while SCOP effects on DA turnover resulted attenuated in the whole striatum and abolished in synaptosomes. We conclude that drug-induced AA oxidation is likely to occur in the extracellular space and requires intact corticostriatal glutamatergic pathways. The latter may play an enabling role in SCOP behavioral effects.