Abstract
Central serotonin is implicated in a variety of emotional and behavioral control processes. Serotonin depletion can lead to exaggerated aversive processing and deficient response inhibition, effects that have been linked to serotonin's actions in the amygdala and orbitofrontal cortex (OFC), respectively. However, a direct comparison of serotonin manipulations within the OFC and amygdala in the same experimental context has not been undertaken. This study compared the effects of infusing the serotonin neurotoxin, 5,7-dihydroxytryptamine into the OFC and amygdala of marmosets performing an appetitive test of response inhibition. Marmosets had to learn to inhibit a prepotent response tendency to choose a box containing high-incentive food and instead choose a box containing low-incentive food, to obtain reward. OFC infusions caused long-lasting reductions in serotonin tissue levels, as revealed at postmortem, and exaggerated prepotent responses. In contrast, the significantly reduced prepotent responses following amygdala infusions occurred at a time when serotonin tissue levels had undergone considerable recovery, but there remained residual reductions in extracellular serotonin, in vivo. These opposing behavioral effects of serotonin manipulations in the same experimental context may be understood in terms of the top-down regulatory control of the amygdala by the OFC.
| Original language | English |
|---|---|
| Pages (from-to) | 1668-1675 |
| Number of pages | 8 |
| Journal | Cerebral Cortex |
| Volume | 20 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - Jul 2010 |
Keywords
- behavioral inhibition
- prepotent response
- OBSESSIVE-COMPULSIVE DISORDER
- PREFRONTAL SEROTONIN DEPLETION
- BASOLATERAL AMYGDALA
- COGNITIVE INFLEXIBILITY
- IMPULSIVE CHOICE
- MACAQUE MONKEYS
- MEDIAL STRIATUM
- LESIONS
- RESPONSES
- DEPRESSION