Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
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Regional cerebral glucose metabolism in subjects with histories of polysubstance abuse was compared to that in control subjects who were drawn from the same community. The substance abuse group showed lower absolute metabolic rates for glucose in lateral occipital gyrus and higher normalized metabolic rates in temporal and frontal areas, including orbitofrontal cortex. It is suggested that some patterns of brain function associated with polysubstance abuse may represent consequences of drug exposure, or they could reflect pre-existing differences that may be relevant to the etiology and maintenance of polysubstance abuse.
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Neuropsychopharmacology · Apr 1995
Effects of D3/D2 dopamine receptor agonists and antagonists on prepulse inhibition of acoustic startle in the rat.
Prepulse inhibition (PPI) is the normal reduction in a startle response that occurs when a weak stimulus ("prepulse") precedes the startling stimulus by 30 to 500 msec. Schizophrenic patients are deficient in this operational measure of sensorimotor gating; therefore, animal models of deficient PPI may provide information useful in the understanding and treatment of schizophrenia. Prepulse inhibition is disrupted in rats by systemic administration of direct dopamine agonists having affinity for the D2 subtype family (D2, D3, and D4) of dopamine receptors. ⋯ The dopamine agonists quinpirole, 7-hydroxy-N,-N-di-n-propyl-2-aminotetralin (7-OH-DPAT) and apomorphine were approximately equipotent in decreasing PPI. Pretreatment with haloperidol (13 to 130 nmol/kg sc), but not equimolar doses of UH 232, prevented the disruption of PPI produced by the highest dose (0.6 mumol/kg sc) of each agonist. Given the 100-fold higher affinity of haloperidol relative to UH 232 for D2 receptors, and equal relative affinities of these antagonists for D3 receptors, these data are consistent with previous studies suggesting that dopamine agonists may modulate PPI in the rat through the D2 subtype of dopamine receptors.
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Neuropsychopharmacology · Apr 1994
Comparative StudyBaseline and fear-potentiated startle in panic disorder patients.
The present study investigated whether patients with panic disorder had an increase in the startle response and whether this effect, if present, was specific to anticipatory anxiety. The eyeblink component of the acoustic startle reflex was measured in a paradigm involving the anticipation of electric shocks (fear-potentiated startle) in 34 patients with panic disorder and 49 healthy controls. Startle was also recorded in the absence of specific threat at the beginning and at the end of the testing. ⋯ The difference reached significance only during the fear-potentiated startle phase, however. Startle was nonsignificantly reduced in the older patients (age > or = 39 years old), compared to the older controls. The results are discussed in terms of the contextual effects of the experimental setting.
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Neuropsychopharmacology · Sep 1992
Comparative StudyPain perception in self-injurious patients with borderline personality disorder.
Pain ratings during the cold pressor test were significantly lower in female inpatients with borderline personality disorder who report that they do not experience pain during self-injury (BPD-NP group, n = 11), compared with similar patients who report that they do experience pain during self-injury (BPD-P group, n = 11), and normal female subjects (n = 6). Pain ratings were not significantly different in the BPD-P and normal control groups. ⋯ Only anxiety was significantly lower in the normal control group following the cold pressor test. The implications and limitations of these preliminary findings are discussed.
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Neuropsychopharmacology · Oct 1991
Subtle signs of prenatal maldevelopment of the hand ectoderm in schizophrenia: a preliminary monozygotic twin study.
Genes that predispose to psychosis may act by making individuals more vulnerable to the disruptive effects of various prenatal insults. Fetal organogenesis is mostly completed in the first prenatal trimester. The second trimester is a critical period of massive neuronal migration from the periventricular germinal matrix to the cortex. ⋯ Discrepancies in hand morphology between two identical (monozygotic [MZ]) co-twins may be temporal markers, that is, the "fossilized" evidence of various ischemic and other nongenetic insults that may have affected one fetus more than his MZ co-twin during that early part of the second trimester. In twins, prenatal insults (e.g., ischemia) frequently do not affect both co-twins to the same extent, so we examined seven putative markers of prenatal injury to the hand in 24 MZ twin pairs discordant for schizophrenia or delusional disorder. Compared with well co-twins, the affected co-twins had significantly higher total scores of fourth- and fifth-month dysmorphological hand anomalies.