Exposure to an enriched environment facilitates motor recovery and prevents short-term memory impairment and reduction of striatal BDNF in a progressive pharmacological model of parkinsonism in mice.

Previous studies showed that the repeated administration with a low dose of reserpine (RES) induces a gradual appearance of motor signs and cognitive deficits compatible with parkinsonism in rodents. Environmental stimulation has neuroprotective effects in animal models of neurodegenerative damage, including acutely induced parkinsonism. We investigated the effects of exposure to an enriched environment (EE) on motor, cognitive and neuronal (levels of tyrosine hydroxylase, TH and brain derived neurotrophic factor, BDNF) deficits induced by a progressive model of Parkinson's disease (PD) in mice. Male mice were repeatedly treated with vehicle or 0.1mg/kg of RES (s.c) and kept under two housing conditions: standard environment (SE) and EE. In animals kept in SE, the treatment with RES induced deficits in motor function (catalepsy test, open field and oral movements), in novel object recognition (NOR) and plus-maze discriminative avoidance tasks. The environmental stimulation facilitated the recovery of motor deficits assessed by the catalepsy test after the end of treatment. Additionally, exposure to EE prevented the memory deficit in the NOR task. Treatment with RES induced a reduction in the number of TH positive cells in SNpc and VTA, which recovered 30days after the end of treatment. Finally, RES reduced the levels of BDNF in the striatum and the exposure to the EE prevented this effect. These results suggest that plastic brain changes induced by EE promote beneficial effects on the progression of neuronal impairment related to PD.

Nuclear organization of the substantia nigra, ventral tegmental area and retrorubral field of the common marmoset (Callithrix jacchus): A cytoarchitectonic and TH-immunohistochemistry study.

It is widely known that the catecholamine group is formed by dopamine, noradrenaline and adrenaline. Its synthesis is regulated by the enzyme called tyrosine hydroxylase. 3-hydroxytyramine/dopamine (DA) is a precursor of noradrenaline and adrenaline synthesis and acts as a neurotransmitter in the central nervous system. The three main nuclei, being the retrorubral field (A8 group), the substantia nigra pars compacta (A9 group) and the ventral tegmental area (A10 group), are arranged in the die-mesencephalic portion and are involved in three complex circuitries - the mesostriatal, mesolimbic and mesocortical pathways. These pathways are involved in behavioral manifestations, motricity, learning, reward and also in pathological conditions such as Parkinson's disease and schizophrenia. The aim of this study was to perform a morphological analysis of the A8, A9 and A10 groups in the common marmoset (Callithrix jacchus - a neotropical primate), whose morphological and functional characteristics support its suitability for use in biomedical research. Coronal sections of the marmoset brain were submitted to Nissl staining and TH-immunohistochemistry. The morphology of the neurons made it possible to subdivide the A10 group into seven distinct regions: interfascicular nucleus, raphe rostral linear nucleus and raphe caudal linear nucleus in the middle line; paranigral and parainterfascicular nucleus in the middle zone; the rostral portion of the ventral tegmental area nucleus and parabrachial pigmented nucleus located in the dorsolateral portion of the mesencephalic tegmentum. The A9 group was divided into four regions: substantia nigra compacta dorsal and ventral tiers; substantia nigra compacta lateral and medial clusters. No subdivisions were made for the A8 group. These results reveal that A8, A9 and A10 are phylogenetically stable across species. As such, further studies concerning such divisions are necessary in order to evaluate the occurrence of subdivisions that express DA in other primate species, with the aim of characterizing its functional relevance.

Age-related changes in neurochemical components and retinal projections of rat intergeniculate leaflet.

Aging leads to several anatomical and functional deficits in circadian timing system. In previous works, we observed morphological alterations with age in hypothalamic suprachiasmatic nuclei, one central component of this system. However, there are few data regarding aging effects on other central components of this system, such as thalamic intergeniculate leaflet (IGL). In this context, we studied possible age-related alterations in neurochemical components and retinal projections of rat IGL. For this goal, young (3 months), adult (13 months), and aged (23 months) Wistar rats were submitted to an intraocular injection of neural tracer, cholera toxin subunit b (CTb), 5 days before a tissue fixation process by paraformaldehyde perfusion. Optical density measurements and cell count were performed at digital pictures of brain tissue slices processed by immunostaining for glutamic acid decarboxylase (GAD), enkephalin (ENK), neuropeptide Y (NPY) and CTb, characteristic markers of IGL and its retinal terminals. We found a significant age-related loss in NPY immunoreactive neurons, but not in immunoreactivity to GAD and ENK. We also found a decline of retinal projections to IGL with age. We conclude aging impairs both a photic environmental clue afferent to IGL and a neurochemical expression which has an important modulatory circadian function, providing strong anatomical correlates to functional deficits of the aged biological clock.

A cytoarchitectonic and TH-immunohistochemistry characterization of the dopamine cell groups in the substantia nigra, ventral tegmental area and retrorubral field in the rock cavy (Kerodon rupestris).

The 3-hydroxytyramine/dopamine is a monoamine of the catecholamine group and it is a precursor of the noradrenaline and adrenaline synthesis, in which the enzyme tyrosine hydroxylase acts as a rate-limiting enzyme. The dopaminergic nuclei retrorubral field (A8 group), substantia nigra pars compacta (A9 group) and ventral tegmental area (A10 group) are involved in three complex circuitries named mesostriatal, mesocortical and mesolimbic, which are directly related to various behavioral manifestations such as motor control, reward signaling in behavioral learning, motivation and pathological manifestations of Parkinson's disease and schizophrenia. The aim of this study was to describe the delimitation of A8, A9 and A10 groups and the morphology of their neurons in the brain of the rock cavy (Kerodon rupestris), a typical Brazilian Northeast rodent belonging to the suborder Hystricomorpha, family Caviidae. Coronal and sagittal sections of the rock cavy brains were submitted to Nissl staining and TH immunohistochemistry. The organization of these dopaminergic nuclei in the rock cavy brain is very similar to that found in other animals of the Rodentia order, except for the presence of the tail of the substantia nigra, which is found only in the species under study. The results revealed that, apart some morphological variations, A8, A9 and A10 groups are phylogenetically stable brain structures.

Changes in the suprachiasmatic nucleus during aging: implications for biological rhythms

Animals have neural structures that allow them to anticipate environmental changes and then regulate physiological and behavioral functions in response to these alterations. The suprachiasmatic nucleus of the hypothalamus (SCN) is the main circadian pacemaker in many mammalian species. This structure synchronizes the biological rhythm based on photic information that is transmitted to the SCN through the retinohypothalamic tract. The aging process changes the structural complexity of the nervous system, from individual nerve cells to global changes, including the atrophy of total gray matter. Aged animals show internal time disruptions caused by morphological and neurochemical changes in SCN components. The effects of aging on circadian rhythm range from effects on simple physiological functions to effects on complex cognitive performance, including many psychiatric disorders that influence the well-being of the elderly. In this review, we summarize the effects of aging on morphological, neurochemical, and circadian rhythmic functions coordinated by the main circadian pacemaker, the SCN...

Changes in the suprachiasmatic nucleus during aging: implications for biological rhythms

Animals have neural structures that allow them to anticipate environmental changes and then regulate physiological and behavioral functions in response to these alterations. The suprachiasmatic nucleus of the hypothalamus (SCN) is the main circadian pacemaker in many mammalian species. This structure synchronizes the biological rhythm based on photic information that is transmitted to the SCN through the retinohypothalamic tract. The aging process changes the structural complexity of the nervous system, from individual nerve cells to global changes, including the atrophy of total gray matter. Aged animals show internal time disruptions caused by morphological and neurochemical changes in SCN components. The effects of aging on circadian rhythm range from effects on simple physiological functions to effects on complex cognitive performance, including many psychiatric disorders that influence the well-being of the elderly. In this review, we summarize the effects of aging on morphological, neurochemical, and circadian rhythmic functions coordinated by the main circadian pacemaker, the SCN.(AU)

Affordances em ambientes domésticos e desenvolvimento motor de pré­escolares / Affordances in the home environment and motor development in preschool children / Affordances en ámbitos domésticos e desarrollo motor de pré escolares

O objetivo deste estudo foi verificar a correlação entre as oportunidades de estimulação motora no ambiente doméstico e o nível de desenvolvimento motor (DM) em 12 pré-­escolares de 36 a 42 meses de idade. Utilizou-­se o questionário Affordances in the Home Enviroment for Motor Development – AHEMD – 18­42 meses e a bateria de Teste de Desenvolvimento Motor Grosso ­ 2ª Edição (TDMG­2). Os resultados demonstram uma deficiência significativa na promoção de oportunidades para o DM das crianças no ambiente doméstico, sem, contudo influenciar negativamente o desenvolvimento motor das mesmas. Infere­se que o ritmo maturacional destas crianças e principalmente a ação de outros microssistemas podem estar suprindo as deficiências detectadas no ambiente doméstico.

The aim of this research was to verify the correlation between the opportunities of motor stimulation in the home environment and the level of motor development (MD) in 12 preschool children with 36 to 42 months old. The questionnaire Affordances in the home Environment For Motor Development­ AHEMD ­18­42 Months and the test of gross motor development 2° Edition (TGMD­2) were used. The results showed one significant deficiency in the promotion of opportunities for the MD of children in the home environment, without negatively influencing their motor development. It also demonstrates that these children’s maturational rhythm, and mainly the action of other Microsystems, can be supplying detected deficiencies in the home environment.

El propósito de esta investigación fue de comprobar la correlación entre las oportunidades de estimulación motora en el ámbito doméstico y el nível de desarrollo motor (DM) en 12 pre escolares de 36 a 42 meses de edad. Se utilizo cuestionario Affordances in the Home Enviroment for Motor Development – AHEMD – 18­42 Months y tambien el Teste de Desarrollo Motor Grueso – 2ª Edición (TDMG­2). Los resultados demuestran una deficiencia significativa en la promoción de oportunidades para el DM de los niños en el ámbito doméstico, sin embargo influir negativamente el desarrollo motor de las mismas. Se deduce que el ritmo maduracional de estos niño y principalmente la acción de otros microsistema pueden estar supliendolas deficiencias detectadas en el ámbito doméstico.

Nuclear organization of the serotonergic system in the brain of the rock cavy (Kerodon rupestris).

Serotonin, or 5-hydroxytryptamine (5-HT), is a substance found in many tissues of the body, including as a neurotransmitter in the nervous system, where it can exert different post-synaptic actions. Inside the neuro-axis, 5-HT neurons are almost entirely restricted to the raphe nuclei of the brainstem. As such, 5-HT-immunoreactivity has been considered a marker of the raphe nuclei, which are located in the brainstem, at or near the midline. The present study investigated distribution of serotonergic neurons in the brain of the rock cavy (Kerodon rupestris), a rodent species inhabiting the Brazilian Northeast. The cytoarchitectonic location of serotonergic neurons was established through a series of 5-HT immunostained sections, compared with diagrams obtained from adjacent coronal and sagittal sections stained by the Nissl method. The following nuclei were defined: the rostral group, consisting of rostral linear raphe, caudal linear raphe, median and paramedian raphe, dorsal raphe, and pontine raphe nuclei, and the caudal group composed of raphe magnus, raphe pallidus and raphe obscurus nuclei. Other serotonergic neuronal clusters, such as the supralemniscal group and the rostral and caudal ventrolateral medulla oblongata clusters, were found outside the midline. Rare 5-HT-producing neurons were identified in the lateral parabrachial nucleus and in the pontine reticular formation, mostly along fibers of the lateral lemniscus. Despite exhibiting some specializations, the picture outlined for serotonergic groups in the rock cavy brain is comparable to that described for other mammalian species.

5-HT(1B) receptor in the suprachiasmatic nucleus of the common marmoset (Callithrix jacchus).

Serotonin (5-HT) is involved in the fine adjustments at several brain centers including the core of the mammal circadian timing system (CTS) and the hypothalamic suprachiasmatic nucleus (SCN). The SCN receives massive serotonergic projections from the midbrain raphe nuclei, whose inputs are described in rats as ramifying at its ventral portion overlapping the retinohypothalamic and geniculohypothalamic fibers. In the SCN, the 5-HT actions are reported as being primarily mediated by the 5-HT1 type receptor with noted emphasis for 5-HT(1B) subtype, supposedly modulating the retinal input in a presynaptic way. In this study in a New World primate species, the common marmoset (Callithrix jacchus), we showed the 5-HT(1B) receptor distribution at the dorsal SCN concurrent with a distinctive location of 5-HT-immunoreactive fibers. This finding addresses to a new discussion on the regulation and synchronization of the circadian rhythms in recent primates.

Serotonin and circadian rhythms

All mammal behaviors and functions exhibit synchronization with environmental rhythms. This is accomplished through an internal mechanism that generates and modulates biological rhythms. The circadian timing system, responsible for this process, is formed by connected neural structures. Pathways receive and transmit environmental cues to the central oscillator, the hypothalamic suprachiasmatic nucleus, which mediates physiological and behavioral alterations. The suprachiasmatic nucleus has three major inputs: the retinohypothalamic tract (a direct projection from the retina), the geniculohypothalamic tract (an indirect photic projection originating in the intergeniculate leaflet), and a dense serotonergic plexus from the raphe nuclei. The serotonergic pathway, a source of non-photic cues to the suprachiasmatic nucleus, modulates its activity. The importance of raphe nuclei in circadian rhythms, especially in photic responses, has been demonstrated in many studies. Serotonin is the raphe neurotransmitter that triggers phase shifts, inhibits light-induced phase-shifts, and plays a role in controlling the sleep-wake cycle. All data to date have demonstrated the importance of the raphe, through serotonergic afferents, in adjusting circadian rhythms and must therefore be considered a component of the circadian timing system. The aim of this paper is to review the literature addressing the involvement of serotonin in the modulation of circadian rhythm.(AU)

Serotonin and circadian rhythms

All mammal behaviors and functions exhibit synchronization with environmental rhythms. This is accomplished through an internal mechanism that generates and modulates biological rhythms. The circadian timing system, responsible for this process, is formed by connected neural structures. Pathways receive and transmit environmental cues to the central oscillator, the hypothalamic suprachiasmatic nucleus, which mediates physiological and behavioral alterations. The suprachiasmatic nucleus has three major inputs: the retinohypothalamic tract (a direct projection from the retina), the geniculohypothalamic tract (an indirect photic projection originating in the intergeniculate leaflet), and a dense serotonergic plexus from the raphe nuclei. The serotonergic pathway, a source of non-photic cues to the suprachiasmatic nucleus, modulates its activity. The importance of raphe nuclei in circadian rhythms, especially in photic responses, has been demonstrated in many studies. Serotonin is the raphe neurotransmitter that triggers phase shifts, inhibits light-induced phase-shifts, and plays a role in controlling the sleep-wake cycle. All data to date have demonstrated the importance of the raphe, through serotonergic afferents, in adjusting circadian rhythms and must therefore be considered a component of the circadian timing system. The aim of this paper is to review the literature addressing the involvement of serotonin in the modulation of circadian rhythm

Rugosidade superficial de compósitos microparticulados e nanoparticulados após acabamento e polimento / Surface roughness of microparticulated and nanoparticulated composites after finishing and polishing procedures

Objetivo: Avaliar a rugosidade superficial de resinas compostas microparticulada (Durafill, Heraeus Kulzer Weihrheim, Germany), nanoparticuladas 4 Seasons (Ivoclar Vivadent, Schaan, Liechtenstein), Esthet X (Dentsply, Milford, DE, USA) Point 4 (Kerr CO, Orange, CA, USA),Filtek-Supreme (3M-ESPE, Dental Products, St. Paul, MN, USA). Métodos: Após o acabamento com pontas diamantadas F (KG Sorensen, Barueri, Brasil) e polimento com pontas de silicone Politipit (IvoclarVivadent, Schaan, Liechtenstein) nas cores cinza, verde e rosa, foram realizadas quatro etapas de finalização, uma de acabamento e três de polimento, simulando o acabamento e polimento de uma restauração de resina fotopolimerizável. Dez espécimens de cada resina composta foram mensurados quanto aos valores de rugosidade superficial com rugosímetro (Mitutoyo Corporation, Tokyo, Japan) após cada etapa de acabamento e polimento. Resultados: Os resultados demonstraram que as resinas nanoparticuladas e microparticuladas apresentaram diferenças significantes quanto aos valores de rugosidade superficial em todos os estágios de acabamento e polimento. Conclusão: Entre as resinas nanoparticuladas, a 4 Seasons (Ivoclar Vivadent, Schaan, Liechtenstein) e a Point 4 (Kerr CO, Orange, CA, USA), assim como a resina microparticulada Durafill (Heraeus Kulzer Weihrheim, Germany), apresentaram baixos valores de rugosidade superficial após esgotarem-se todas as etapas de acabamento e polimento.

Objective: To evaluated the surface roughness of one microparticulate resin composite Durafill (Heraeus Kulzer Weihrheim, Germany) and four nanoparticulate resins 4 Seasons (Ivoclar Vivadent, Schaan, Liechtenstein) Esthet x (Dentsply, Milford, DE, USA), Point 4 and Supreme(3M-ESPE, Dental Products, St. Paul, MN, USA). Methods: After finishing with a diamond bur point (F), and polishing with silicone points of gray, green and pink color Politipit (Ivoclar Vivadent, Schaan, Liechtenstein), four stages of completion were performed, simulating one of finishing and three of polishing a resin restoration. Ten samples of each composite resin were measured for surface roughness with surface profilometer (Mitutoyo Corporation, Tokyo, Japan) after each of finishing and polishing sequence.Results: The results showed that nanoparticulate and microparticulate resins presented a significant difference in the surface roughness values, in all finishing and polishing steps. Conclusion: Of the nanoparticulate resins 4 Seasons (Ivoclar Vivadent, Schaan, Liechtenstein), Point 4 (Kerr CO, Orange, CA, USA), and also microparticulate Durafill (Heraeus Kulzer Weihrheim, Germany) presented significantly lower surface roughness values after completing all the finishing and polishing stages.

Discrete retinal input to the parabrachial complex of a new-world primate, the common marmoset (Callithrix jacchus).

Traditional retinal projections target three functionally complementary systems in the brain of mammals: the primary visual system, the visuomotor integration systems and the circadian timing system. In recent years, studies in several animals have been conducted to investigate the retinal projections to these three systems, despite some evidence of additional targets. The aim of this study was to disclose a previously unknown connection between the retina and the parabrachial complex of the common marmoset, by means of the intraocular injection of cholera toxin subunit b. A few labeled retinal fibers/terminals that are detected in the medial parabrachial portion of the marmoset brain show clear varicosities, suggesting terminal fields. Although the possible role of these projections remains unknown, they may provide a modulation of the cholinergic parabrachial neurons which project to the thalamic dorsal lateral geniculate nucleus.

Influência do tratamento de superfície de um sistema de compósito restaurador indireto sobre a resistência de união ao cisalhamento / Influence of surface treatment of indirect resin system on shear bond strength

O objetivo deste trabalho foi avaliar a influência do tratamento de superfície de um sitema de compósito restaurador indireto sobre a resistência de união ao cisalhamento. Para isto foram usados 100 dentes bovinos e 100 cilindros de belleGlass HP (Kerr), divididos aleatoriamente em 10 grupos com dez amostras em cada grupo. Os grupos foram divididos de acordo com o tratamento de superfície do compósito: grupo 1- somente lixa no 400 (grupo controle); grupo 2 - ácido fluorídrico (HF) 10% durante 3 min.; grupo 3 - silano; grupo 4 - HF 10%/3min. + silano; grupo 5 - óxido de alumínio (OA) 50µm; grupo 6 - Cojet-Sand (CJ) 30µm; grupo 7 - OA 50µm + silano; grupo 8 - OA 50µm + HF 10%/3 min. + silano; grupo 9 - CJ + silano e grupo 10 - CJ + HF 10%/3 min. + silano. A resistência de união ao cisalhamento foi realizada por uma máquina de ensaio universal EMIC DC 10000, com uma velocidade 0,5mm por minuto. Os testes mostraram valores mais altos para o grupo 10 (15,21 MPa), porém não diferindo estatisticamente dos grupos 6 - (13,66 MPa); 9 - (13,42 MPa); 8 - (13,06 MPa) e grupo 5 - (12,54 MPa). Sob as condições deste estudo, concluímos que a microabrasão com CJ e OA, associadas ao silano parece ser o tratamento indicado para o bellesGlass HP antes da cimentação

Shear bond strength of direct composite repairs in indirect composite systems.

Indirect composite restorations may require repair during clinical service. This study evaluated the shear bond strength of direct composite repairs in indirect composites after four surface treatment procedures. Cylinders of three indirect composites (n = 10 per group) received the following surface treatment: sandpaper finishing (control group), 50 microm aluminum oxide sandblasting, 50 microm aluminum oxide sandblasting (plus 10% fluoridric acid etching), and 30 microm silaned silicon sandblasting. Repair procedure was simulated with the application of an adhesive agent and packing of a direct composite. After storage for one hour in relative humidity and 23 hours in distilled water at 37 degrees C, the specimens were tested for shear bond strength using a universal testing machine at a crosshead speed of 0.5 mm/min. Groups treated with aluminum oxide sandblasting or CoJet Sand had the highest mean values of shear bond strength with no statistically significant difference between the two techniques.

Avaliação da rugosidade superficial de compósitos microíbridos e condensáveis após acabamento e polimento / Evaluation of surface roughness of microhibrid and condensable composite after finishing and polishing procedures

O objetivo deste estudo foi avaliar a rugosidade de superfície dos compósitos microíbridos Charisma, Fill Magic, Z250 e Tetric Ceram e dos compósitos condensáveis Alert, Surefil, Fill Magic e Tetric Ceram HB após a realização de procedimento de acabamento e polimento com pontas diamantadas finas (F), extrafinas (FF), pontas siliconizadas (Ennhance) e disco de feltro com pasta abrasiva (Diamond R). Foram confeccionadas dez amostras para cada compósito, as quais foram submetidas à medição de rugosidade de superfície após cada etapa da sequência de polimento através de uma rugosímetro (Mitutoyo). Os resultados obtidos demonstraram que, para os compósitos microíbridos, houve diferença significativa da rugosidade de superfície em todas as etapas de acabamento e polimento, sendo Charisma a apresentar a menor rugosidade final; já para os condesáveis, o polimento com pasta não reduziu significativamente a rugosidade da superfície em relação às pontas Enhance, com a Tetric Ceram HB e o Surefil obtendo a menor rugosidade final