ISSN:
1432-1912
Keywords:
Key words Autoreceptor
;
Dopamine (DA)
;
D3
;
Ontogeny
;
Synthesis
;
(±) 7-OH-DPAT
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Dopamine synthesis modulation by the D2-family agonist (±)-7-OH-DPAT was explored in striatum, accumbens, and prefrontal cortex of 10–40 day old rats using the gamma-butyrolactone (GBL) autoreceptor model. GBL produced an age-dependent increase in dopamine synthesis that was inhibited by (±) 7-OH-DPAT (0.1–13.5 mg/kg) at all ages and antagonized by eticlopride in the nucleus accumbens and striatum. The ID50 of (±) 7-OH-DPAT increased with age, suggesting decreased autoreceptor sensitivity with maturation. In prefrontal cortex, (±) 7-OH-DPAT inhibited synthesis between 10–30 days, with no evidence of autoreceptor function at 40 days. Dopamine synthesis was also inhibited with the D3/D2 agonist quinpirole at 15 days of age in vivo and yielded similar results to those obtained with (±) 7-OH-DPAT. Finally, under conditions that result in low D2 receptor affinity, D3 specificity was examined in vitro at 15 days with (±) 7-OH-DPAT, which produced comparable (yet more potent) effects to those observed in vivo. These findings illustrate D3 autoreceptor-like activity in ascending dopamine regions and provide further support for transient prefrontal cortex autoreceptor-like function that recedes by puberty.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/PL00005038
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