Available online
Description
The programme is concerned with the nervous control of relatively simple patterns of activity in invertebrates. Two animal species are used in the programme; one is the earthworm and the other the ...mollusc Tritonia. In both cases the question asked is what roles do the central and peripheral nervous sytems have in controlling the behaviour under investigation.
The programme is concerned with the nervous control of relatively simple patterns of activity in invertebrates. Two animal species are used in the programme; one is the earthworm and the other the ...mollusc Tritonia. In both cases the question asked is what roles do the central and peripheral nervous sytems have in controlling the behaviour under investigation.
| Module code and title: | SDT286, Biological bases of behaviour |
|---|---|
| Item code: | SDT286; 03 |
| First transmission date: | 12-02-1972 |
| Published: | 1972 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:23:20 |
| + Show more... | |
| Producer: | John Groom |
| Contributors: | Neil Chalmers; and D A Dorsett |
| Publisher: | BBC Open University |
| Keyword(s): | Central/peripheral nervous system; Earthworm; Flexions; Invertebrates; Locomotive control; Nervous control; Oscillograph; Tritonia mollusc |
| Footage description: | CU shot of an earthworm moving over earth. Neil Chalmers introduces the programme. Chalmers uses a diagram of an earthworm section to point out the locomotive equipment of the worm (Both nerves and muscles). Chalmers describes 3 possible methods of locomotive control in earthworms - central nerve, peripheral nerve or combination of the two. Chalmers describes and performs the following experiments which could be used to demonstrate which of the three possibilities above is the correct one. Chalmers stretches an intact and then a bisected worm. Contractions follow stretching in both cases. Chalmers severs the central nerve chord of an earthworm. He explains how this is done without killing the worm but demonstrates on a dead worm. He then brings out an earthworm which has a severed central nerve chord. Chalmers tests for the effect, of stretching in this speciman. No contractions result for the area of missing nerve chord. Chalmers explains how a control for this experiment is devised. Chalmers explains and demonstrates an experiment in which all peripheral influences are excluded. In this experiment stretch is eliminated from parts of the animal. Contractions still take place although in a modified form. Chalmers holds up a model of a mollusc Tritonia. He explains why this animal is ideal for behavioural studies in the laboratory. Shots of micrograph showing section of Tritonia brain. Film shots of Tritonia escape movements during a starfish attack. Movements are simple and stereotyped. Shots of the same movement induced in the laboratory. Chalmers introduces D.A. Dorsett. Dorsett shows and describes the apparatus which is used to study the nervous system of Tritonia. He explains how the animal is prepared and mounted in the apparatus. Film sequence shows an actual Tritonia being prepared and placed into the experimental apparatus. The neuron controlling the swimming (escape) movement in the animal is stimulated. Swimming motion results. Dorsett with a large model of Tritonia brain. He points out its constituent parts particularly the areas which control dorsal and ventral flexions. Film sequence shows Tritonia being stimulated to make the swimming movement. The effect on the neuron controlling this reaction is shown. Dorsett shows an oscillograph tracing of a dorsal swimming sequence. This tracing is from an intact Tritonia brain. Dorsett compares this tracing with one from a dissected out Tritonia brain. The tracings are very similar. Dorsett next shows a tracing from ventral flexion neurons after stimulation. This tracing is from an isolated brain. Dorsett compares this tracing with one for the dorsal flexion neuron. Dorsett shows the dorsal and ventral flexion tracings for an intact brain |
| Master spool number: | 6LT/70261 |
| Production number: | 00521_2134 |
| Videofinder number: | 2090 |
| Available to public: | no |
