The serotonin 5-HT4 subtype receptor is predominantly localized into anatomical structures linked to memory and cognition. A few experimental studies report that the acute systemic administration of selective 5-HT4 agonists has ameliorative effects on memory performance, and that these effects are reversed by contemporary administration of 5-HT4 receptor antagonists. To verify whether this procognitive action occurs via the activation of the cholinergic nucleus basalis magnocellularis (NBM)-cortical pathways, we examined the effects of RS67333, a selective partial agonist of the 5-HT4 receptor, on rat performance in a place recognition task upon local administration of the drug into the NBM area. The intra-NBM administration of RS67333 enhances the acquisition (200-500 ng/0.5 µL) and the consolidation (40-200 ng/0.5 µL) of the place recognition memory. These effects are reversed by pretreatment with the selective 5-HT4 receptor antagonist RS39604 (300 ng/0.5µL). Conversely, the recall of memory is not affected by the 5-HT4 agonist. Our results indicate that 5-HT4 receptors located within the NBM may play a role in spatial memory and that the procognitive effect of RS67333 is due, at least in part, to the potentiation of the activity of cholinergic NBM-cortical pathways.The putative role of the serotonergic system in memory improvement or recovery from impaired cognitive performance has received considerable attention over the last years. In this context, radioligand binding and autoradiography studies performed in different animal species revealed that the serotonin 5-HT4 subtype receptor, a G-protein-coupled receptor activating the adenylate cyclase system, is predominantly localized in anatomical structures linked to memory and cognition (Eglen et al. 1995b;Waeber et al. 1996). In addition, direct evidence of the physiological relevance of 5-HT4 subtype receptors in learning and memory processes has been reported by several authors (Fontana et
Although in bipolar patients the main therapeutic indication of atypical antipsychotics is the management of acute mania, several observations suggest that these agents may exert antidepressant as well as anti-manic effects. The main goal of the present work was to evaluate the putative antidepressant effect of chronic olanzapine (Ola) (0.02-0.1 or 0.5 mg/kg.d), in comparison to haloperidol (Hal) (0.2 mg/kg.d) and sodium valproate (VPA) (5 or 30 mg/kg.d), in rats exposed to a protocol of chronic mild stress. The tricyclic compound amitriptyline (Ami) (5 mg/kg.d) was used as reference drug. The results indicate that Ola, in a rodent model of depression, has protective effects against the stress-induced anhedonia. Compared to Hal and VPA, Ola shows a greater antidepressant activity and is as effective as Ami in preventing the anhedonic state. The effects of Ola and Ami, however, have a different time-course. A full reversion of the anhedonia by Ami appears after a latency of 4 wk, whereas the effect of Ola is already evident 1 wk after the beginning of the chronic treatment. Moreover, the recovery from anhedonia at the end of the stress protocol and after drug cessation was more rapid in groups of rats pretreated with Ola or VPA than in the group of saline-pretreated rats. In conclusion, the results indicate that 0.02 mg/kg.d Ola causes a rapid and sustained antidepressant-like effect, while all other anti-manic treatments show loss of efficacy at 3 wk. Taken together, these observations support the hypothesis that Ola has a broader pharmacotherapeutic profile than solely as an antipsychotic or anti-manic agent.
Utilizando-se 15 cadelas no pós-parto, são descritas as características da involução uterina e determinado o diâmetro do útero, por meio de exames seriados de ultra-som em modo B (tempo real), no período de zero a 28 dias pós-parto. O diâmetro uterino declina progressivamente, sem influência da ordem de parto ou tamanho da ninhada. As características ultra-sonográficas do útero são melhor visualizadas na primeira semana pós-parto e a qualidade da imagem diminui com o progresso da involução. Pela técnica usada são visualizadas apenas três camadas constituintes da parede uterina.
Utilizaram-se 15 cadelas gestantes submetidas a cesariana e posteriormente a exames ultra-sonográficos seriados, em modo B (tempo real), para averiguação do diâmetro uterino nos dias 0, 3, 7, 14 e 21 pós-cesariana, com o objetivo de verificar a influência do ato cirúrgico na involução uterina. Os resultados (média e desvio-padrão, em centímetros) registrados para os dias estudados foram, respectivamente: 3,99+0,71; 3,27+0,51; 2,60+0,54; 2,01+0,34; 1,28+0,24. A involução uterina pós-cesariana seguiu o mesmo padrão do puerpério do parto normal, assim como as características das imagens ultra-sonográficas. O parto cesariana não influenciou no padrão de involução uterina.
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