Role of 5-HT in stress, anxiety, and depression

There are conflicting results on the function of 5-HT in anxiety and depression. To reconcile this evidence, Deakin and Graeff have suggested that the ascending 5-HT pathway that originates in the dorsal raphe nucleus (DRN) and innervates the amygdala and frontal cortex facilitates conditioned fear, while the DRN-periventricular pathway innervating the periventricular and periaqueductal gray matter inhibits inborn fight/flight reactions to impending danger, pain, or asphyxia. To study the role of the DRN 5-HT system in anxiety, we microinjected 8-OH-DPAT into the DRN to inhibit 5 HT release. This treatment impaired inhibitory avoidance (conditioned fear) without affecting one-way escape (unconditioned fear) in the elevated T-maze, a new animal model of anxiety. We also applied three drug treatments that increase 5-HT release from DRN terminals: 1) intra-DRN microinjection of the benzodiazepine inverse agonist FG 4172, 2) intra-DRN microinjection of the excitatory amino acid kainic acid, and 3) intraperitoneal injection of the 5-HT releaser and uptake blocker D-fenfluramine. All treatments enhanced inhibitory avoidance in the T-maze. D-Fenfluramine and intra-DRN kainate also decreased one-way escape. In healthy volunteers, D-fenfluramine and the 5-HT agonist mCPP (mainly 5-HT2C) increased, while the antagonists ritanserin (5-HT2A/(2C)) and SR 46349B (5-HT2A) decreased skin conductance responses to an aversively conditioned stimulus (tone). In addition, D-fenfluramine decreased, whereas ritanserin increased subjective anxiety induced by simulated public speaking, thought to represent unconditioned anxiety. Overall, these results are compatible with the above hypothesis. Deakin and Graeff have suggested that the pathway connecting the median raphe nucleus (MRN) to the dorsal hippocampus promotes resistance to chronic, unavoidable stress. In the present study, we found that 24 h after electrolytic lesion of the rat MRN glandular gastric ulcers occurred, and the immune response to the mitogen concanavalin A was depressed. Seven days after the same lesion, the ulcerogenic effect of restraint was enhanced. Microinjection of 8-OH-DPAT, the nonselective agonist 5-MeO-DMT, or the 5-HT uptake inhibitor zimelidine into the dorsal hippocampus immediately after 2 h of restraint reversed the deficits of open arm exploration in the elevated plus-maze, measured 24 h after restraint. The effect of the two last drugs was antagonized by WAY-100135, a selective 5-HT1A receptor antagonist. These results are compatible with the hypothesis that the MRN-dorsal hippocampus 5-HT system attenuates stress by facilitation of hippocampal 5-HT1A-mediated neurotransmission. Clinical implications of these results are discussed, especially with regard to panic disorder and depression.

Habilidades sociais e comportamento do motorista entre universitárias usuárias e não usuárias de bebida alcoólica

Pós-graduação em Educação - FFC

O uso do treino de habilidades sociais em pessoas com fobia social na terapia comportamental

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

O uso do treino de habilidades sociais em pessoas com fobia social na terapia comportamental

The effects of an intervention in social skills were assessed in four university students with ages between 19 and 31, with social phobia diagnosis. The performance in social skills as well as performance-compatible disorder was assessed before, after the intervention, and follow-up in four months later, by the instruments: SCID-I, Mini-SPIN, QACC-VU and IHS in a multiple baseline design among participants. The intervention programmed twelve weekly meetings in which the researcher discussed socially skilled alternatives to the described difficulties; leaded dialogued theoretical explanations about the theme of the meeting and also performed functional assessments and repertory training of the participants. It was observed deficits such as public speaking, starting and maintaining conversation in the participants’ social skills repertory, which are consistent with the criteria for social phobia and the difficulties into the adapting to university. After the intervention, the participants left difficulties in public speaking, performance characteristic compatible with the social phobia diagnosis and they also increased social repertory, although it is still necessary the improvement of other skills, such as expressing positive feeling.

The role of social skills in social anxiety of university students

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Contribuição de práticas argumentativas para a democratização de debates científicos em aulas de Física

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)