Accumbens D2 modulation of sensorimotor gating in rats: assessing anatomical localization.
The normal reduction in acoustic startle amplitude caused by a weak prepulse (prepulse inhibition; PPI) is deficient in schizophrenic patients and in rats after systemic or intraaccumbens treatment with the D2 dopamine agonist quinpirole. We examined the anatomical substrates of the PPI-disruptive effects of intraaccumbens quinpirole. PPI was significantly reduced in a dose-dependent manner by quinpirole infusion into the medial accumbens shell region, the lateral accumbens core region, and an intermediate central region. There was a weak tendency for this quinpirole effect to be more pronounced in core and central accumbens regions than in the medial and anteromedial accumbens. Using the retrograde tracer Nuclear yellow, shell and core regions were verified to receive different patterns of limbic cortical innervation. Although the accumbens appears to have a complex and functionally diversified intrinsic anatomy, the accumbens D2 modulation of sensorimotor gating appears to be distributed across several different accumbens subregions.
Wan
F J
FJ
Department of Neuroscience, UCSD School of Medicine, La Jolla 92093-0804.
Geyer
M A
MA
Swerdlow
N R
NR
D000161:Acoustic Stimulation; D000818:Animals; D001562:Benzimidazoles; D018491:Dopamine Agonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004873:Ergolines / Q000494:pharmacology; D005456:Fluorescent Dyes; D008032:Limbic System / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology; D008297:Male; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology; D009714:Nucleus Accumbens / Q000033:anatomy & histology / Q000502:physiology*; D019257:Quinpirole; D051381:Rats; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000502:physiology*; D013216:Reflex, Startle / Q000187:drug effects / Q000502:physiology*; D000096926:Benzenesulfonamides
D001562:Benzimidazoles; D018491:Dopamine Agonists; D004873:Ergolines; D005456:Fluorescent Dyes; D019257:Quinpirole; D017448:Receptors, Dopamine D2; C036574:nuclear yellow; D000096926:Benzenesulfonamides