Available online
Description
The programme looks at the mechanism of the nerve impulse, illustrated mainly by animations and also at laboratory techniques in neurophysiology, both in vitro and in vivo.
The programme looks at the mechanism of the nerve impulse, illustrated mainly by animations and also at laboratory techniques in neurophysiology, both in vitro and in vivo.
| Module code and title: | SD286, "Biology, brain and behaviour" |
|---|---|
| Item code: | SD286; 04 |
| First transmission date: | 11-04-1981 |
| Published: | 1981 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:31 |
| + Show more... | |
| Producer: | Neil Cameron |
| Contributors: | Geoff Einon; F. M.(Frederick M.) Toates |
| Publisher: | BBC Open University |
| Keyword(s): | Neurons; Neurophysiology |
| Footage description: | Film shots (slow Motion) of a frog leaping. Commentary by Geoff Einon introduces the programme. Geoff Einon examines and explains an experimental set up which consists of a dissected out frog gastronemius muscle and its attached sciatic nerve. These are hooked up to a transducer and oscilloscope. He stimulates the nerve electrically and this causes the muscle to contract. The contractions are shown as a trace on the oscilloscope. An animated diagram gives an overview of the mechanism of a nerve impulse travelling down a nerve axon. Commentary by Fred Toates explains the details of ionic concentrations and movements during the nerve's resting state, during an action potential on a nerve segment, during propagation of the action potential and during the recovery phase. More animations and still diagrams are shown. Geoff Einon introduces an experiment in which the firing of an individual nerve cell, that of the giant axon of the squid, is monitored on an oscilloscope screen. Shots of a squid in its natural environment, of the giant axon being dissected out of the animal, of the recording electrode being inserted into the axon and of the oscilloscope screen. Geoff Einon goes on to describe one technique for recording neuronal activity in vivo. He demonstrates a piece of stereotactic equipment which allows recording dectrodes to be introduced into the animal's brain with great precision so that activity of a single nerve cell can be recorded. The results of such an experiment are shown on an oscilloscope screen. A technique for recording the activity of populations of neurones in the brain is demonstrated. The technique, called evoked potential recording, involves placing an electrode to a subject's head and displaying the electrical activity on an oscilloscope. Commentary by Geoff Einon explains the principles behind the experiment, particularly the signal averaging of the output signal which eliminates random spontaneous activity. Geoff Einon summarises the programme. |
| Master spool number: | HOU3588 |
| Production number: | FOUS176E |
| Videofinder number: | 2076 |
| Available to public: | no |
