The Journal of Neuroscience, July 15, 2000, 20(14):5449-5460
Regulation of Rat Cortex Function by D1 Dopamine Receptors in the
Striatum
Heinz
Steiner and
Stephen T.
Kitai
Department of Anatomy and Neurobiology, University of Tennessee,
College of Medicine, Memphis, Tennessee 38163
Interactions between the basal ganglia and the cerebral
cortex are critical for normal goal-directed behavior. In the present study, we used immediate-early genes (c-fos, zif
268) as functional markers to investigated how basal ganglia
output altered by stimulation/blockade of D1 dopamine receptors in the
striatum affects cortical function. Systemic administration of the
mixed D1/D2 receptor agonist apomorphine (3 mg/kg) increased
immediate-early gene expression in the striatum and throughout most of
the cortex. Unilateral intrastriatal infusion of the selective D1
receptor antagonist SCH-23390 (0.5-10 µg) blocked this response
bilaterally in striatum and cortex in a dose-dependent manner. Even
apparently regionally restricted blockade of striatal D1 receptors
attenuated gene expression throughout striatum and cortex in both
hemispheres. Intrastriatal administration of the D1
antagonist inhibited apomorphine-induced sniffing/whisking, whereas other motor behaviors were unaffected. To determine whether such changes in cortical gene expression could reflect altered cortical
function, we examined the effects of blocking striatal D1
receptors on whisker stimulation-evoked immediate-early gene expression
in the sensorimotor cortex. Apomorphine increased sensory stimulation-evoked gene expression in the barrel cortex, and
intrastriatal infusion of SCH-23390 attenuated this effect. These
results suggest that stimulation of D1 dopamine receptors in the
striatum exerts a widespread facilitatory effect on cortical function.
Key words:
dopamine; striatum; basal ganglia; cortex; barrel; c-fos; zif 268; immediate-early genes
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