Nonhuman primates offer unique opportunities to study the effects of genes, environments, and their interaction, on physiology and complex behavior. We examined genotype and early environment ...contributions to CNS function in a large sample of rhesus monkeys. In humans, length variation of the serotonin (5-HT) transporter (5-HTT) gene-linked polymorphic region (5-HTTLPR) that results in allelic variation in 5-HTT expression is associated with decreased serotonergic function and 5-HT-mediated psychopathology. We report that an analogous variation of the gene's regulatory region in monkeys interacts with early experience to affect central 5-HT functioning. Monkeys with deleterious early rearing experiences were differentiated by genotype in cerebrospinal fluid concentrations of the 5-HT metabolite, 5-hydroxyindoleacetic acid, while monkeys reared normally were not. These findings demonstrate an environment-dependent effect of the rh5-HTTLPR genotype on CNS 5-HT function and suggest nonhuman primates may provide an important avenue for investigating gene/environment interactions using candidate genes for physiological and behavioral traits.
Neurophysiological and pathological effects of ethanol may be mediated, to an important extent, via the glutamatergic system. Animal studies indicate the acute effects of ethanol disrupt ...glutamatergic neurotransmission by inhibiting the response of the N-methyl-D-aspartate (NMDA) receptor. Persistent attenuation of glutamatergic neurotransmission by chronic ethanol exposure results in the compensatory up-regulation of NMDA receptors. Whether glutamatergic neurotransmission and oxidative stress are enhanced during ethanol withdrawal in humans is unknown.
CSF was obtained from 18 matched comparison subjects and from 18 patients with alcohol dependence 1 week and 1 month after cessation of ethanol ingestion. CSF samples were analyzed for excitatory neurotransmitters, gamma-aminobutyric acid (GABA), and markers for oxidative stress.
The alcohol-dependent patients' CSF levels of aspartate, glycine, and N-acetylaspartylglutamate were all higher than those of the comparison subjects, and their concentration of GABA was lower. In addition, there were significant correlations between excitatory neurotransmitters and oxidative stress markers, which suggest that the two mechanisms may play an interactive role in neurotoxicity mediated by ethanol withdrawal.
The data suggest that augmentation of excitatory neurotransmission may lead to enhanced oxidative stress, which, in concert with reduced inhibitory neurotransmission, may contribute to the symptoms of ethanol withdrawal and associated neurotoxicity in humans. Whether these abnormalities represent a trait- or state-dependent marker of ethanol dependence remains to be resolved.
Studies from several countries, representing diverse cultures, have reported an association between violent suicide attempts by patients with unipolar depression and personality disorders and low ...concentrations of the major serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the cerebrospinal fluid (CSF). Related investigations have documented a similar inverse correlation between impulsive, externally directed aggressive behavior and CSF 5-HIAA in a subgroup of violent offenders. In these individuals, low CSF 5-HIAA concentrations are also associated with a predisposition to mild hypoglycemia, a history of early-onset alcohol and substance abuse, a family history of type II alcoholism, and disturbances in diurnal activity rhythm. These data are discussed in the context of a proposed model for the pathophysiology of a postulated "low serotonin syndrome."
Nonselective cyclooxygenase (COX) inhibitors have been reported to decrease the frequency of upper aerodigestive cancers. Ketorolac tromethamine oral rinse has been shown to resolve another ...COX-dependent process, periodontal disease, without incurring gastrointestinal side effects. This trial evaluated if a topically delivered oral rinse containing ketorolac was as safe as and more effective than oral rinse alone in reducing the area of oral leukoplakia.
57 patients were randomized (2:1 ratio) in a double-blind, placebo-controlled study of ketorolac (10 ml of a 0.1% ketorolac rinse solution; n = 38) or placebo (10 ml of rinse solution; n = 19) given twice daily for 30 s over 90 days. Primary end point was evaluated visually obtaining bidimensional measurement of the size of leukoplakia lesion(s) at entry and at 90 days. Secondary end point was histological assessment of the leukoplakia as sampled by serial punch biopsy and independently reviewed by three pathologists.
The patients included 67% males, 11% non-Caucasian, and 86% used tobacco with no significant differences between the two arms. Both rinses were well tolerated with good compliance, and there was no significant difference in adverse events (P = 0.27). Major response rate (complete response and partial response) was 30% for ketorolac and 32% for the placebo arm. There was no significant difference in change in histology between the two arms.
Local delivery of a COX-containing oral rinse was well tolerated but produced no significant reduction in the extent of leukoplakia compared with the placebo. However, the favorable response rate to placebo arm remains unexplained and additional investigation of the tissue penetration with ketorolac is warranted.
The repeatedly observed strong positive correlation between 5-hydroxyindoleacetic acid (5HIAA) and homovanillic acid (HVA) in human cerebrospinal fluid (CSF) prompted an investigation to see if ...conclusions concerning possible interactions between brain serotonin and dopamine turnover could be reached from human CSF concentrations of these acid metabolites. CSF data from patients with depressive disorders diagnosed according to the RDC from Sweden (n = 140) and from the National Institute of Mental Health (n = 35) were used to test structural hypotheses by two statistical approaches--LISREL analysis and logistic regression. Results from both men and women were unequivocal: 5HIAA "controls" HVA, interpretable as a regulatory action of serotonin turnover on dopamine turnover. In women, only 5HIAA was affected by age, height and body size (higher in elderly, short and stout women); no similar relationships were seen in males. The concept of a serotonergic regulation of dopamine turnover was tested on brain punch analyses of serotonin and dopamine and their metabolites in two sets of dogs in a large number of brain areas. Results confirm a facilatory effect of serotonin on indices of dopamine turnover in many brain regions, especially brain stem and hypothalamus. The animal data validate the data analytic approach in humans.
Effects of Serotonin on Memory Impairments Produced by Ethanol Weingartner, Herbert; Rudorfer, Matthew V.; Buchsbaum, Monte S. ...
Science (American Association for the Advancement of Science),
1983-Jul-29, Letnik:
221, Številka:
4609
Journal Article
Recenzirano
Subjects treated with low or high doses of ethanol demonstrated impaired memory, particularly in tests involving the recall of poorly learned information. Zimelidine, an inhibitor of serotonin ...reuptake, reversed this ethanol-induced impairment. The serotonin neurotransmitter system may mediate learning and memory in humans and may determine some of the effects of alcohol on higher mental functions.
Patients taking lithium often report difficulties in concentration, memory, learning, and attention and many of these complaints are verified on psychometric testing. Laboratory tests of cognitive ...functions in healthy volunteers on chronic lithium demonstrate that disruptions in memory-learning processes are apparent at the time of memory retrieval. Subjects, following chronic lithium treatment, produce more errors of commission in remembering previously occurring events while errors of omission appear to be unaffected. These effects are different from those produced by other psychoactive drugs that can also selectively alter and disrupt cognitive processes.
As a probe of the noradrenergic system in depression, single oral doses of the tricyclic antidepressant desipramine (100 mg) and placebo were administered to unipolar and bipolar depressed patients ...and healthy volunteers. Plasma concentrations of norepinephrine (NE) were determined 2-3 hours after dosing, with subjects in supine and upright positions. On the placebo day plasma NE was low in a subset of bipolar patients; both groups of depressives demonstrated an exaggerated increase in plasma NE upon standing. After desipramine dosing, the orthostatic procedure resulted in even greater relative increments in plasma NE in both patient groups, with no change in volunteers. These data are consistent with noradrenergic dysregulation in depression.
PDF
