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Remote laboratories can provide distant learners with practical acquisitions which would otherwise remain precluded. Our proposal here is a remote laboratory on a behavioural test (open field test), with the aim of introducing learners to the observation and analysis of stereotyped behaviour in animals. A real-time video of a mouse in an experimental arena is streamed over the Internet from a server computer connected with the laboratory apparatus to a client computer managed by an instructor. Learners observe the video projected by the client computer and record on their PCs the positions of the mouse in the arena and the behavioural patterns produced. Input-output interactions with the test apparatus are made possible by a remote, concurrently operated digital interface. Learners' recordings can be individually and collectively analysed, to assess behavioural trends and effects induced by client-commanded experimental treatments; the quality and the improvements in accuracy of the learners' recordings can also be estimated. A first implementation of the remote laboratory, carried out on two groups of undergraduate students, gave positive indications on the feasibility and the efficiency of the project, and on its didactic efficacy.

The antennal flagellum nerve of Homarus americanus was investigated as to structure, number and size of axons, and propagation velocity. Frequency distributions of axon diameters, evaluated at four equidistant levels on the flagellum, ranged with continuity between 0.25 and 14.7 µm, with maximum at 0.5-1.5 µm. Axons 0.5-1.5 µm in diameter were more abundant at the distal level, indicating sensory specialization near the tip. The total axon numbers increased from about 9000 at the distal level to about 45 000 at the base. Axons of different size followed different patterns of increase in number from tip to base; these patterns were examined in relation to structural features of the flagellum, and to hypotheses of association with known or unidentified receptors. Propagation velocities were distributed with continuity, in the range between 3.39 and 0.24 m/s; velocity-diameter correspondences were outlined. [ABSTRACT FROM AUTHOR]

Glucose solutions (160 mg/kg and 320 mg/kg body weight) were injected into the haemolymphatic sinuses of Aplysia depilans through an implanted cannula, and the effects on feeding behaviour were noted. The feeding parameter examined was the ingestion velocity of a standard weed ribbon (Ulva): it was evaluated from the time taken to ingest each of ten successive centimetres of the ribbon. The ingestion velocity was found to decrease in a dose‐dependent manner following glucose injection. No irregularities or alterations in the shape of the feeding curves were induced. The effect became progressively larger during the 60 minutes following injection, and appeared to level off afterwards. [ABSTRACT FROM PUBLISHER]

The ingestion of Ulva strips 10 cm long, 1 or 2 cm wide (narrow and wide ribbon) was automatically recorded and analysed in Aplysia depilans. Graphs expressing ribbon displacements as a function of time were obtained. They showed a sequence of alternate slow and fast movements (slow and fast “phase"). The duration of a slow phase was positively correlated with the fast phase following it, but not with the one preceding it. The elementary cycle was characterized in standard conditions by three parameters: 1) length ingested (L); 2) time duration (D); 3) ratio between fast phase duration and whole cycle duration (F). The parameters remained stable during a sequence. Compared with narrow ribbon ingestion, wide ribbon ingestion led to a rise in D and a fall in L, and resulted in a reduction of the feeding efficiency. D rose in partially fed animals. With a narrow ribbon, the application of loads exerting a traction opposing ingestion did not induce significant variations in L, D, or F; with a wide ribbon, L and F fell as load increased. [ABSTRACT FROM PUBLISHER]