Response of male mice to odours of female mice in different stages of oestrous cycle: Self-grooming behaviour and the effect of castration.

The behavioural assays were carried out in a Y-maze wherein intact, castrated and testosterone-treated male mice were exposed to oestrus and non-oestrus urine samples. The intact male mice investigated more frequently and spent more time in the Y-maze arm with oestrus urine than in that with non-oestrus urine. In contrast, the castrated mice were not attracted to oestrus urine, whereas testosterone-treated mice showed preference for oestrus urine. The rate of self-grooming was higher in intact males in case of exposure to oestrus urine while the rate was lower with respect to non-oestrus urine. However, castrated mice exhibited less self-grooming behaviour which was partially restored by testosterone treatment. The results suggest that self-grooming behaviour is an indicator of detection and discrimination of oestrus by males, and supports the androgen role in male chemosensory ability to discriminate between oestrus and non-oestrus female odours.

Thigmotactic responses in an open-field

The goal of the present study was to investigate the role of thigmotaxis (the tendency to remain close to vertical surfaces) in rat exploratory behavior in an open-field. Thigmotaxis was investigated in a parametric way, using 24 experimentally adult naive male Wistar rats (210-230 g). Exploratory behavior was studied in an open-field (N = 12) in 5-min sessions and behavior was analyzed in terms of where it occurred: in areas surrounded by two, one, or no walls. Another group of rats (N = 12) was studied in an open-field with blocks placed near two of the corners so as to make these corner areas surrounded by three walls. The floor of the open-fields was divided into 20-cm squares in order to locate the exact place of occurrence of each behavior. The following behaviors were recorded: entries into the squares, rearings, and groomings. In both types of open-field the rats chose to remain longer in the squares surrounded by the largest possible number of walls. In one of the open-fields, the mean time (seconds) spent in squares surrounded by two walls was longer than the time spent in squares surrounded by one or no walls (37.2, 7.7, and 1.8 s, respectively). In the other open-field, the mean time spent in squares surrounded by three walls was longer than the time spent in squares surrounded by two, one or no walls (41.7, 20.4, 7.0, and 2.6 s, respectively). Other measures presented a similar profile. These results indicate that rats are sensitive to the number of walls in an environment and prefer to remain close to them.

Bradypophila garbei EM radypus variegatus no Río de Janeiro / Bradypophila garbein in bradypus variegatus at Rio de Janeiro, Brazil

De quarenta examplares de ectoparasitos colhidos de uma preguica (Bradypus variegatus) cativa na Fundacao Rio-Zoo, procedeu-se a identificacao do material. Os ectoparasitos semelhantes a pequena mariposa, removidos de entre a pelagem e crostas da pele, foram trabalhados entre dezembro/93 e outubro/94. Procedeu-se a investigacao bibliográfica com base na literatura do Museu Nacional do Rio de Janeiro e do Laboratório de Morfofisiologia e Patogenia de Carrapatos-Sanidade Animal (LMPC/SA) do Departamento de Parasitologia Animal do Instituto de Biologia da Universidade Federal Rural do Rio de Janeiro (DPA/IB/UFRRJ). Para a análise das característic desses lepidópteros foi necessário o processamento para a descamacao das asas, que permitisse a identificacao a nivel de genero e espécie. A metodologia utilizada para tanto foi desenvolvida especificamente para este Colecao Entomológica do Instituto Oswaldo Cruz sob o número PIR-001. Todo este estudo enquadra-se no projeto interinstitucional envolvendo a Fundacao Jardim Zoológico do Rio de Janeiro e a Universidade Federal Rural do Rio de Janeiro, representada pelo LMPC-SA/DPA/IB

Effects of massive telencephalic lesions on the organization of behavior in pigeons (Columba livia)

The effect of massive lesions of the telencephalon on the repertoire of captive pigeons were investigated. The behavior of four birds with an intact telencephalon was compared to that of four birds submitted to ablation of telencephalic structures. Behavioral audio recording was done according to previously defined categories in three daily sessions for fifteen days. Experimental birds were followed up for month. Immediately after the lesion, operated birds showed decreases in the occurrence of different behaviors such as coording movements, feeding, interaction, preening, maintenance, exploration and vocalization and increases in locomotion and discrete movements of the body when compared to the control birds (P<0.05). Recovery of exploration (P<0.05), feeding and localization was during the follow-up period. These data are interpreted as suggestive of a functional role of the telencephalon in the organization of behavior and a long-term recovery of behavior after detelencephalation