Atividades comportamentais e comportamento alimentar de rã touro, Lithobates catesbeianus (Shaw, 1802), de pigmentação normal e albina em cativeiro

The behavior of bullfrogs reared in captivity must be well understood to support management practices that use efficient feeding regimes. In general, bullfrogs reared in captivity have normal pigmentation, but to develop an enhanced product, some studies have investigated the introduction of albino individuals in frog farms. The present study characterized the behavior of both pigmented and albino bullfrogs reared in captivity. In an initial experiment, 48 bullfrogs (70.5 ± 25.6 g) housed in small stalls were fed once a day at random times. Frogs were filmed and the images showed that both the pigmented and albino varieties behaved similarly: food intake was more frequent at dawn followed by light periods; moving and resting in dry areas may be associated to feeding events; frogs appeared to anticipate feeding time and to rest in the water more frequently in periods other than feeding time; daylight is the recommended period for feeding both pigmented and albino frogs. In a second experiment, 72 albino bullfrogs were fed at fixed times (10 a.m. or 4 p.m.) in small stalls. An initial weight of 23.8 ± 7.6 g was considered to evaluate frog performance, and after the animals reached 60.0 ± 20.0 g, they were filmed for behavior analyses. Food intake varied as a function of feeding time, and frogs were more likely to eat during the early hours of the day and immediately after receiving fresh food. Frogs fed only in the afternoon changed their behavior. Food supplied twice a day stimulated the albino frogs to eat at different times, but did not increase growth. Although fresh food stimulated feeding behavior, food intake was more frequent at dawn. Food supplied at this time of day should therefore be further investigated. The results did not indicate a more suitable feeding time (10 a.m. or 4 p.m.) for albino bullfrogs, or any advantage in using two feedings per day. The results provide xvi important information about bullfrogs in terms of food supply regime and activity preferences throughout the day. This novel information will contribute to future studies in this area

Caracterização citoarquitetônica e por imunoistoquímica para tirosina-hidroxilase da substância negra, área tegmentar ventral e zona retrorubral do Sagui (Callithrix jacchus)

It is known that the catecholamine group is constituted by dopamine, noradrenaline and adrenaline, in which the synthesis is regulated by an enzyme named tyrosine hydroxylase. Thus, 3-hydroxytyramine/dopamine (DA) is a precursor of the noradrenaline and adrenaline synthesis and acts as a neurotransmitter in the central nervous system. The three main nuclei, named 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 complexes circuitries - the mesostriatal, mesolimbic and mesocortical pathways. These pathways are related to behavioral manifestations, motricity, learning, reward and pathologies such as Parkinson’s Disease and Schizophrenia. Thus, the aim of this study was to perform de morphological analysis of the A8, A9 and A10 nuclei of the common marmoset (Callithrix jacchus). The marmoset is a neotropical primate, whose morphological and functional characteristics supports the suitability of use of this animal in biomedical research. Coronal sections of the marmoset brain were submitted to cytoarchitectonic characterization and TH-immunohistochemistry. Based on the morphology of the neurons, it was possible to subdivide the A10 group in seven regions: interfascicular nucleus, raphe rostral linear nucleus and raphe caudal linear nucleus, in the middle line; paranigral and parainterfascicular nucleus, in the middle zone; rostral portion of the ventral tegmental area nucleus and parabrachial pigmented nucleus, located in the dorsolateral portion of the mesencephalic tegmentum. A9 group was divided into four regions: substantia nigra compacta dorsal and ventral tiers; substantia nigra compacta lateral and medial clusters. No subdivisions were founded into A8 group. These results revealed that A8, A9 and A10 are phylogenetically conserved between species, but it’s necessary to expand the studies about this compartmentalization, investigating its occurrence in other primate species or investigating its functional relevance.

Expressão imuno-histoquímica das proteínas E-Caderina e BCL2 e nevos melanociticos orais e cutâneos

Melanocytic nevi (MNs) are benign melanocytic proliferations of cells, which can be found in the skin and mucous coat, including the oral mucosa. However, skin NMs are more common when compared to those that affect the oral mucosa. The molecular mechanisms involved in the development of nevi and the factors that can influence the migration pattern of the nevus cells are little explored. The aim of this study was to analyze the immunohistochemical expression of E-cadherin protein and Bcl-2 in oral / skin NMs and relate them to the clinical characteristics (gender, age, location, exposure to solar radiation) and histopathological types. 36 cases of oral NMs and 34 Skin NMs were analyzed. The immunohistochemistry was used of the protein E-cadherin and bcl-2, which were analyzed the intensity (weak, moderate and strong) and distribution marking (diffuse and focal). The immunoreactivity also analyzed as to the types of nevus cells (epithelioid cells -A, -B lymphocyte and fibroblast-like -C). Statistical analysis was performed using the chi-square tests of Pearson and Spearman correlation with significance level set at 5%. Of the 70 cases of NMs, 82.9% were female, 48.6% aged 26-50 years, 51.4% were diagnosed histologically as intradermal / intramucosal nevi and 80% were NMs acquired. Immunohistochemical expression of BCL2 and E-cadherin were variables in the sample and showed no association with clinical parameters. The expression of bcl-2 and E-cadherin were variable according to the types of nevus cells (A, B and C) (P = 0.001). The expression of bcl-2 was more diffuse in congenital MNs (p = 0.002). E-cadherin was positive in 83.3% of MNs <1cm (p = 0.001) and exhibited weak staining in 73.9% of MNs that were in exposed areas (p = 0.010). Based on these results, it is suggested that the E-cadherin has a modulating effect on the migratory properties of NMs, and bcl-2 is a marker of MNs with increased proliferative capacity.