The refractory period of the sensory synapses of the lateral geniculate nucleus

Bishop, Peter; Evans, W. A.

doi:10.1113/jphysiol.1956.sp005664

Cited by 37 publications

(34 citation statements)

References 15 publications

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“…These have shown that one afferent impulse is sufficient to cause a single discharge in the geniculate cells: that the 'sublimal fringe' is small and the synaptic delay short and constant. The nucleus behaves rather similarly in these experiments to the monosynaptic pathway in spinal motoneurones Bishop, Jeremy & McLeod, 1953;Bishop & Evans, 1956;Bishop & Davis, 1960).…”

mentioning

confidence: 84%

Types of response and organization of simple receptive fields in cells of the rabbit's lateral geniculate body

Arden¹

1963

The Journal of Physiology

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confidence: 84%

Types of response and organization of simple receptive fields in cells of the rabbit's lateral geniculate body

Arden¹

1963

The Journal of Physiology

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“…Certainly there was no marked decrease or disappearance of the post-synaptic response as was observed by Eccles & McIntyre (1953) Each set of results shows the mean + S.E. of mean, followed by the range of the average values for each cat and the number of animals, except for the asterisked results which are taken from Bishop & Evans (1956) and which show the mean and the range of values.…”

Section: Resultsmentioning

confidence: 99%

“…It is possible that a reduced blood supply might affect the metabolism of the retinal ganglion cells and optic nerve fibres and lead to this reduction in conduction velocity. Absolutely refractory period was not measured in normal cats and comparison was made with the values obtained in a previous investigation in this laboratory (Bishop & Evans, 1956). The mean value for the treated cats (0-82 msec) was practically identical with that for normal cats (0.81 msec) and was not significantly different (P > 0.05) from that of dark cats (0.71 msec).…”

Section: Resultsmentioning

confidence: 99%

Disuse in the lateral geniculate nucleus of the cat

Burke¹,

Hayhow²

1968

The Journal of Physiology

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SUMMARY1. An attempt has been made to produce disuse in the lateral geniculate nucleus (LGN) of the cat, in the synapses between the optic nerve fibres and the principal cells of the nucleus. Evidence is produced that destruction of the visual receptor cells by iodoacetate or 1,5-di(p-aminophenoxy) pentane dihydrochloride effectively silences the optic nerve discharge and so achieves this result.2. Disuse of the LGN synapses does not cause any decrease in synaptic efficiency. The LGN response to a single stimulus to the optic nerve was not appreciably altered, and the depression which normally follows single or repeated stimuli was much reduced or absent. This increased responsiveness was unaffected by prolonged tetanization of the optic nerve during the experiment.3. Two possible explanations of the increased responsiveness are suggested: a post-synaptic 'decentralization '-hypersensitivity and an increased output of transmitter per impulse. The relevance of these results to theories of learning is discussed.4. The LGN response of adult cats kept in complete darkness for periods of up to 966 days was not appreciably different from that in the normal cat and there was little or no increased responsiveness. This suggests that many retinal ganglion cells continue to discharge in total darkness for long periods. There is a possibility that disuse may develop after a long time in the dark.

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“…A re-examination of the results of Bishop & Evans (1956) shows that the early phase of supernormality referred to above extends from about * Ophthalmic Research Institute of Australia Fellow.…”

Section: (Received 12 August 1959)mentioning

confidence: 99%

“…One of the most important factors determining such a modification is the nature of the recovery cycle of the synapses and neurones in the nucleus. A detailed account of the recovery of the geniculate synapse from the refractory state has already been published (Bishop & Evans, 1956). Recovery from refractoriness in this nucleus is principally determined by the rate at which normal conduction ability returns in the presynaptic fibres.…”

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The recovery of responsiveness of the sensory synapses in the lateral geniculate nucleus

Bishop¹,

Davis²

1960

The Journal of Physiology

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The normal ganglion-cell discharge from the retina consists of a brief highfrequency burst of impulses. The short refractory period and prolonged phase of supernormality in the recovery cycle of the optic nerve and tract fibres are properties well suited to handle such a discharge (Bishop, Jeremy & Lance, 1953). The ganglion-cell discharge may, however, undergo important modification in the lateral geniculate nucleus before relay to the cerebral cortex. One of the most important factors determining such a modification is the nature of the recovery cycle of the synapses and neurones in the nucleus. A detailed account of the recovery of the geniculate synapse from the refractory state has already been published (Bishop & Evans, 1956). Recovery from refractoriness in this nucleus is principally determined by the rate at which normal conduction ability returns in the presynaptic fibres. Slowed conduction in relatively refractory axons means that the absolutely refractory period of the synapse is greater the longer the effective presynaptic pathway. An upper value of 0'85 msec was set for the absolutely refractory period, with conditioning and testing stimuli applied to the presynaptic pathway (optic tract) about 10 mm from the lateral geniculate nucleus. The geniculate neurones were always capable of responding as soon as conduction became possible in optic tract fibres. By stimulation of the optic nerve and with spike height as an index, the relatively refractory periods of the presynaptic and postsynaptic spikes recorded in the lateral geniculate nucleus were 1-7 and 1-6 msec, respectively. Supernormal excitability on the part of the geniculate neurones commences while the optic nerve fibres are still relatively refractory.It is the aim of the present paper to describe the stages of the recovery cycle from refractoriness up till 5 sec after the discharge of the geniculate neurones. A re-examination of the results of Bishop & Evans (1956) shows that the early phase of supernormality referred to above extends from about

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The refractory period of the sensory synapses of the lateral geniculate nucleus

Cited by 37 publications

References 15 publications

Types of response and organization of simple receptive fields in cells of the rabbit's lateral geniculate body

Types of response and organization of simple receptive fields in cells of the rabbit's lateral geniculate body

Disuse in the lateral geniculate nucleus of the cat

The recovery of responsiveness of the sensory synapses in the lateral geniculate nucleus

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