Oxotechnetium 99mTcO[SN(R)S][S] complexes as potential 5-HT1A receptor imaging agents.

A series of 99mTcO[SN(R)S][S] complexes carrying the 1-(2-methoxyphenyl)piperazine moiety on the tridentate ligand [SN(R)S] was synthesized. For structural characterization and for in vitro binding assays the analogous oxorhenium complexes were prepared. As demonstrated by appropriate competition binding tests in rat hippocampal preparations, all oxorhenium analogues showed affinity for the 5-HT(1A) receptor binding sites with IC(50) values at the nanomolar range (IC(50)= 5.

Inverse relationship of hippocampal serotonin to avoidance behavior, serotonergic activation by emotional stress differentiated by estrous cycle and surgical stress.

The hippocampus is involved in learning, affect, and the neurobiology of stress. After recording individual emotional reactivity (ER) during handling for vaginal smear screening (VSS), serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA), in the hypothalamus-preoptic area (HY-PA) and hippocampus were studied in two rat lines with different susceptibility to Freund's adjuvant arthritis (FAA), in relation to active avoidance behavior (AB), and under basal conditions in the FAA susceptible strain, in relation to ER, cycle stage and 20 h prior surgical stress. FAA susceptible rats compared to non-susceptible under equally low ER, showed higher AB, but lower 5-HIAA and 5-HIAA/5-HT ratio, under basal conditions, and upon termination of avoidance assay, only in hippocampus.

Differential alterations in basal and D-amphetamine-induced behavioural pattern following 6-OHDA or ibotenic acid lesions into the dorsal striatum.

It is well known that the corpus striatum is related to the sterotyped activation induced by several psychostimulants. In this study we analyzed the effects of 6-OHDA, in comparison with those of ibotenic acid lesions, into the dorsal striatum, on the behavioural pattern induced by saline or D-amphetamine treatment. A computerized technique for recording the animal motor activity was developed in order to define in a detailed way the behavioural profile in lesioned and sham-operated rats induced by the saline or D-amphetamine treatment.

Monoaminergic dysregulation on diestrus-2 and estrus through high emotional reactivity.

Rats with great differences in emotional reactivity, during weighing and handling for vaginal smear screening were examined on diestrus-2 (DE-2), proestrus (PE), and estrus (E). Rats with high emotional reactivity (HR), interpreted as trait anxiety, had different serotonergic and dopaminergic profile in hypothalamus-preoptic area (HY-PA) and striatum (Str) and thymus weight lower than that found in rats with low emotional reactivity (LR). In HY-PA of rats with HR when compared to rats with LR, increased 5-hydroxyindoleacetic acid (5-HIAA), 5-HIAA/serotonin (5-HT) ratio, and 3,4-dihydroxyphenylacetic acid (DOPAC) and in Str increased DOPAC and DOPAC/dopamine (DA) ratio were found only on DE-2, paralleled by increased adrenal weight and decreased thymus weight.

Relationship between the thymus and neurochemical changes in the hypothalamus-preoptic area and prefrontal cortex in female rats with delayed puberty.

In female rats, aged 55-58 days with delayed puberty due to deficient growth and environmental stress, 5-hydroxyindoleacetic acid levels and serotonin turnover rate in the hypothalamus-preoptic area as well as body weight, body weight gain and relative weight of ovaries, uterus, adrenals and preputial glands were lower while serotonin and 5-hydroxyindoleacetic acid levels in the prefrontal cortex were higher when compared to normal rats with the latest onset of puberty aged 42-52 days. In rats with delayed puberty, multiple regression analysis revealed a significant negative dependence on dopamine turnover in the hypothalamus-preoptic area for body weight gain and, of all organs, for the relative weight of the thymus. A similar negative significant dependence on serotonin turnover rate in the prefrontal cortex was also found for the relative weight of thymus and spleen.

Risperidone: a novel antipsychotic with many "atypical" properties?

The acute and chronic administration effects of risperidone (Ris), a mixed 5HT2/D2 receptor antagonist, versus haloperidol (Hal) on dopaminergic and serotoninergic activity were investigated in the rat prefrontal cortex (Pfc), and the whole striatum (Str) as well as separately, in dorsal striatum (StrD) and nucleus accumbens (Acb). During acute administration, Hal was found to be more potent than Ris in increasing DA turnover rate in StrD. In contrast, during chronic administration, Ris but not Hal, continued to increase DA turnover activity in StrD.

The neurochemical effects on striatal dopamine turnover rate of N-stearyl dopamine after acute administration in rats.

1. Considerable efforts have been made in order to develop autoreceptor selective agonists for the treatment of schizophrenia and hyperkinetic disorders. 2.

The effect of sumatriptan on brain monoamines in rats.

Clinical data suggests that sumatriptan is effective in the acute treatment of migraine. The vascular effects of the drug have been invoked to explain this antimigraine efficacy. However, the effect of sumatriptan on brain monoamines has not previously been investigated.

GABA-ergic mechanisms in the central control of cough.

The antitussive activity of gabalinoleamide (Gabalid U CB) was studied in 40 non-anaesthetized cats. The antitussive action of the substance was compared to that of codeine (Codein Spofa). Cough was induced by mechanical stimulation using a chronic tracheal cannula.

Environmental lead pollution in Greece.

The blood lead concentration, an index of the environmental lead pollution, was measured in groups of individuals from many parts of greece. The mean blood lead value for urban area individuals was 27.03 micrograms/100 mL for adults, 32.