Changes in activities of dopamine and serotonin systems in the frontal cortex underlie poor choice accuracy and impulsivity of rats in an attention task

Tryptophan Depletion Disrupts the Motivational Guidance of Goal-Directed Behavior as a Function of Trait Impulsivity

“…This appears to contradict existing literature, suggesting that impulsivity implicates diminished 5-HT levels. However, the finding that 5-HT depletion in young healthy volunteers reduced active responding in anticipation of reward is consistent with more recent evidence that certain impulsive behaviors are associated with increased 5-HT levels (Puumala and Sirvio, 1998;Koskinen et al, 2000;Dalley et al, 2002;Passetti et al, 2003). Thus, Dalley et al (2002) revealed a positive correlation between premature responding on the five-choice reactiontime task in anticipation of reward and in vivo 5-HT efflux in the prefrontal cortex.…”

“…Furthermore, recent studies with human volunteers have found that ATD increases impulsive and aggressive behavior, although these effects appear to depend on individual differences in impulsive personality traits (Cherek and Lane, 1999;LeMarquand et al, 1999;Dougherty et al, 1999;Bjork et al, 2000;Marsh et al, 2002;Crean et al, 2002). Findings from studies with clinical human populations are corroborated by an extensive number of animal studies, which suggest that impulsive choice in delaydiscounting paradigms and premature responding in choice reaction-time tasks implicate changes in the 5-HT system (Wogar et al, 1993;Harrison et al, 1997a, b;Puumala and Sirvio, 1998;Koskinen et al, 2000;Mobini et al, 2000;Dalley et al, 2002;Passetti et al, 2003;Winstanley et al, 2003;Liu et al, 2004).…”

Opposing Roles for 5-HT2A and 5-HT2C Receptors in the Nucleus Accumbens on Inhibitory Response Control in the 5-Choice Serial Reaction Time Task

“…Harrison et al (1997a) showed that global 5-HT depletion increases premature responding on the 5CSRTT with concurrent decreases in omissions and latency to make a correct response. Intracerebral administration of the 5-HT neurotoxin, 5,7-dihydroxytryptamine (5,7-DHT) or specific lesions of serotonergic forebrain projections also increase impulsivity as well as impair attentional accuracy (Carli and Samanin, 1992;Jakala et al, 1992;Harrison et al, 1997a, b;Puumala and Sirviö, 1998;Winstanley et al, 2004). The relationship between 5-HT and premature responding in the 5CSRTT is not straightforward however, as Dalley et al (2002) also showed a significant positive correlation between PFC 5-HT and impulsivity consistent with previous reports of a positive correlation between serotonin utilization and premature responding (Puumala and Sirviö, 1998).…”

Deficits in Impulse Control Associated with Tonically-elevated Serotonergic Function in Rat Prefrontal Cortex

“…There is now a substantial body of evidence implicating impaired functioning of brain serotonergic systems in impulsive behavior (Linnoila et al 1983;Harrison et al 1997a;Puumala and Sirviö 1998;Evenden 1999b;Mobini et al 2000). An enduring hypothesis underpinning research in this area is that reduced central serotonin (5-HT) activity, either directly or indirectly, predisposes a subject to impulsive tendencies (Linnoila et al 1983;Wogar et al 1993;Fairbanks et al 2001;Mobini et al 2000).…”

“…Recently, Puumala and Sirviö (1998) evaluated whether differences in cortical monoaminergic function could account for individual variability in attentional performance and impulse control in rats tested in a 5-CSRT task. Post-mortem analysis revealed that 5-HT utilization (ratio of the 5-HT metabolite, 5-hydroxyindoleacetic acid to 5-HT) in the right frontal cortex increased proportionally with impulsive responding during the intertrial interval.…”