Biomaterial Database

Brief monocular deprivation leaves subthreshold synaptic input on neurones of the cat's visual cortex. 1982

C Blakemore, and M J Hawken, and R F Mark

1. We have examined neurones in area 17 of monocularly deprived kittens for subthreshold input in response to visual stimulation through the deprived eye during reversible abolition of activity from the non-deprived eye and during increased excitability of cortical neurones induced by ionophoresis of DL-homocysteic acid (DL-H).2. After two or three days of monocular deprivation, beginning five weeks post-natally, most cortical neurones were dominated by the non-deprived eye. From a sample of forty-three neurones, from three kittens, driven exclusively by the non-deprived eye, only 16% developed responses to stimulation through the deprived eye as a result of reversible pressure blinding of the non-deprived eye. The responses through the deprived eye during pressure blinding usually developed over a period of several minutes and were always transitory: in no cases did the response persist for more than a few minutes after the return of the normal response through the non-deprived eye. Occasionally cells became responsive through the deprived eye during a short period of heightened general excitability after the release of pressure.3. Ionophoretic application of DL-H usually increased the spontaneous activity of cortical neurones. From two kittens monocularly deprived for three days during the fourth or fifth week of life, out of a sample of sixteen cortical neurones initially responsive only through the non-deprived eye, 63% showed responses to visual stimulation through the deprived eye during DL-H application. From a kitten monocularly deprived for 12 d from post-natal day 38, 28% of eighteen initially monocular neurones developed responses through the deprived eye during DL-H application.4. Preliminary results from intracellular recording showed apparently monocular neurones with excitatory input from the deprived eye producing subthreshold synaptic activity in response to moving bars of the same orientation that gave a suprathreshold response through the non-deprived eye.

UI	MeSH Term	Description	Entries
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D012160	Retina	The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.	Ora Serrata
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D003867	Depth Perception	Perception of three-dimensionality.	Stereopsis,Stereoscopic Vision,Depth Perceptions,Perception, Depth,Perceptions, Depth,Stereopses,Stereoscopic Visions,Vision, Stereoscopic,Visions, Stereoscopic
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000344	Afferent Pathways	Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.	Afferent Pathway,Pathway, Afferent,Pathways, Afferent
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012683	Sensory Deprivation	The absence or restriction of the usual external sensory stimuli to which the individual responds.	Deprivation, Sensory,Deprivations, Sensory,Sensory Deprivations
D012684	Sensory Thresholds	The minimum amount of stimulus energy necessary to elicit a sensory response.	Sensory Threshold,Threshold, Sensory,Thresholds, Sensory
D013569	Synapses	Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.	Synapse