Biomaterial Database

Effects of monocular enucleation at birth upon learning of a vertical-horizontal discrimination in hooded rats. 1995

F Yagi, and M Sakai, and Y Ikeda

Neuropsychology Laboratory, Kochi Medical School, Japan.

Previously we have demonstrated that adult albino rats with one eye removed at birth (OEB) relearn a black-white discrimination faster than those monocularly enucleated at maturity (OET) when relearning is conducted after lesioning of the visual cortex contralateral to the remaining eye (Type A experiment). This faster relearning phenomenon is considered to be one behavioral expression of the functioning of the expanded uncrossed visual pathways (expanded UXVPs) resulting from monocular enucleation at birth. However, neither OEBs nor OETs were able to master the discrimination when the experiment was conducted without previous learning following the same surgical treatment (Type B experiment). We hypothesized that this occurs because the cues to discriminate might be close to the threshold of discrimination for either the normal UXVPs or the expanded UXVPs. In order to gain insight into the hypothesis, the present study was undertaken using hooded rats as subjects which genetically possess larger and presumably more efficient functioning UXVPs. The questions addressed were as follows: 1) Whether or not the UXVPs can mediate a vertical-horizontal discrimination in OEBs and OETs. 2) If they can, is there any difference in the upper limit of discrimination capacity between the normal UXVPs and the expanded UXVPs? Three experiments were carried out. In the Type A experiment OEBs relearned discrimination of the 10-mm stripes [0.44 cycles/degree (c/d)] faster than OETs (Experiment 1), yet in the Type B experiment neither OEBs nor OETs were capable of acquiring that discrimination (Experiment 2). However, they could originally master the discrimination equally well when the width of stripes was broadened to 30 mm (0.15 c/d). And when the width of stripes was systematically reduced thereafter, the width of the smallest stripes for the expanded UXVPs to discriminate was found to be 6 mm (0.73 c/d) and that for the normal UXVPs 10 mm (0.44 c/d) [Experiment 3]. These findings were discussed in relation to the hypothesis advanced on our previous data in albino rats.

UI	MeSH Term	Description	Entries
D009473	Neuronal Plasticity	The capacity of the NERVOUS SYSTEM to change its reactivity as the result of successive activations.	Brain Plasticity,Plasticity, Neuronal,Axon Pruning,Axonal Pruning,Dendrite Arborization,Dendrite Pruning,Dendritic Arborization,Dendritic Pruning,Dendritic Remodeling,Neural Plasticity,Neurite Pruning,Neuronal Arborization,Neuronal Network Remodeling,Neuronal Pruning,Neuronal Remodeling,Neuroplasticity,Synaptic Plasticity,Synaptic Pruning,Arborization, Dendrite,Arborization, Dendritic,Arborization, Neuronal,Arborizations, Dendrite,Arborizations, Dendritic,Arborizations, Neuronal,Axon Prunings,Axonal Prunings,Brain Plasticities,Dendrite Arborizations,Dendrite Prunings,Dendritic Arborizations,Dendritic Prunings,Dendritic Remodelings,Network Remodeling, Neuronal,Network Remodelings, Neuronal,Neural Plasticities,Neurite Prunings,Neuronal Arborizations,Neuronal Network Remodelings,Neuronal Plasticities,Neuronal Prunings,Neuronal Remodelings,Neuroplasticities,Plasticities, Brain,Plasticities, Neural,Plasticities, Neuronal,Plasticities, Synaptic,Plasticity, Brain,Plasticity, Neural,Plasticity, Synaptic,Pruning, Axon,Pruning, Axonal,Pruning, Dendrite,Pruning, Dendritic,Pruning, Neurite,Pruning, Neuronal,Pruning, Synaptic,Prunings, Axon,Prunings, Axonal,Prunings, Dendrite,Prunings, Dendritic,Prunings, Neurite,Prunings, Neuronal,Prunings, Synaptic,Remodeling, Dendritic,Remodeling, Neuronal,Remodeling, Neuronal Network,Remodelings, Dendritic,Remodelings, Neuronal,Remodelings, Neuronal Network,Synaptic Plasticities,Synaptic Prunings
D009949	Orientation	Awareness of oneself in relation to time, place and person.	Cognitive Orientation,Mental Orientation,Psychological Orientation,Cognitive Orientations,Mental Orientations,Orientation, Cognitive,Orientation, Mental,Orientation, Psychological,Orientations,Orientations, Cognitive,Orientations, Mental,Orientations, Psychological,Psychological Orientations
D011340	Problem Solving	A learning situation involving more than one alternative from which a selection is made in order to attain a specific goal.
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
D004193	Discrimination Learning	Learning that is manifested in the ability to respond differentially to various stimuli.	Discriminative Learning,Discrimination Learnings,Discriminative Learnings,Learning, Discrimination,Learning, Discriminative
D004292	Dominance, Cerebral	Dominance of one cerebral hemisphere over the other in cerebral functions.	Cerebral Dominance,Hemispheric Specialization,Dominances, Cerebral,Specialization, Hemispheric
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
D000831	Animals, Newborn	Refers to animals in the period of time just after birth.	Animals, Neonatal,Animal, Neonatal,Animal, Newborn,Neonatal Animal,Neonatal Animals,Newborn Animal,Newborn Animals
D001362	Avoidance Learning	A response to a cue that is instrumental in avoiding a noxious experience.	Aversion Behavior,Aversion Learning,Aversive Behavior,Aversive Learning,Avoidance Behavior,Aversion Behaviors,Aversive Behaviors,Avoidance Behaviors,Behavior, Aversion,Behavior, Aversive,Behavior, Avoidance,Behaviors, Aversion,Behaviors, Aversive,Behaviors, Avoidance,Learning, Aversion,Learning, Aversive,Learning, Avoidance
D012683	Sensory Deprivation	The absence or restriction of the usual external sensory stimuli to which the individual responds.	Deprivation, Sensory,Deprivations, Sensory,Sensory Deprivations