Differential effects of kainic acid on dopamine and serotonin metabolism in ventral and dorsal striatal regions

• Published in: Brain research 1997-02, Vol.749 (1), p.139-142
• Main Authors: Guevara, Beatriz H., Hoffmann, Irene S., Cebeddu, Luigi X.
• Format: Article
• Language: English
• Subjects: 3,4-Dihydroxyphenylacetic Acid - metabolism; Acetylcholine release; Animals; Caudate-putamen; Dopamine; Dopamine - metabolism; Dorsal striatum; Excitatory Amino Acid Agonists - pharmacology; Homovanillic Acid - metabolism; Kainic acid; Kainic Acid - pharmacology; Morphine; Neostriatum - drug effects; Neostriatum - metabolism; Olfactory Bulb - drug effects; Olfactory Bulb - metabolism; Olfactory tubercle; Rats; Rats, Sprague-Dawley; Serotonin; Serotonin - metabolism; Stereotaxic Techniques; Ventral striatum
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/S0006-8993(96)01374-1

The comparative effects of kainic acid (KA) on dopamine (DA) and serotonin (5-HT) metabolism in ventral and dorsal striatum were investigated. Local injection of KA into the caudate-putamen (CP) increased by 155% DOPAC (2,3-dihydrophenylacetic acid), by 114% HVA (homovanillic acid) and by 79% 5-HIAA (5-hydroxyindoleacetic acid) concentrations: with little or no effect on monoamine levels. The (DOPAC + HVA)/DA ratio increased from 0.33 ± 0.2 in vehicle-treated to 0.77 ± 0.1 in KA-treated CP. 5-HIAA/5-HT ratio increased from 2.7 ± 0.2 to 5.9 ± 0.1 after KA treatment. However, direct KA injections into the olfactory tubercle (OT), the most ventral part of the ventral striatum, did not alter significantly the levels of DA, 5-HT, DOPAC, HVA or 5-HIAA. Since KA is a neurotoxin which preferentially destroys perykaria and dendrites, leaving unchanged terminal boutons and axons of passage, the lack of effects on DA and 5-HT metabolism in OT suggests, that contrary to the CP, interneurons and projecting neurons in the OT play no role in inhibitory feedback mechanisms to control DA and 5-HT activities.