Biomaterial Database

Electron microscopic and morphometric studies on synaptic plasticity in the hippocampus of the rat following conditioning. 1980

J Wenzel, and E Kammerer, and W Kirsche, and H Matthies, and M Wenzel

1. In 40 three months old Wistar rats (16 trained animals, 14 active controls, 10 passive controls) the influence of learning (brightness discrimination) on the number of electronmicroscopically detectable synapses per area neuropil was studied in the stratum radiatum (CA 1) of the hippocampus. 2. 70 minutes after completion of training, the mean number of synapses has significantly increased as compared to active controls (trained animals 14.26 +/- 2.95 synapses/25 micrometer2; active controls 10.23 +/- 2.80 synapses/25 micrometer2; p less than 0.001). 3. 24 hours after training this increase in trained animals still persisted (trained animals 14.15 +/- 2.60, active controls 11.39 +/- 2.87 synapses/25 micrometer2; p less tha 0.001). 4. 14 days after training, the number of synapses has decreased considerably, but was nevertheless significantly higher than in the active controls (trained animals 12.49 +/- 2.76, active controls 11.45 +/- 3.10; p less than 0.001). 5. The results are discussed with regard to their significance to the different stages of memory formation in the CNS.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
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
D006624	Hippocampus	A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.	Ammon Horn,Cornu Ammonis,Hippocampal Formation,Subiculum,Ammon's Horn,Hippocampus Proper,Ammons Horn,Formation, Hippocampal,Formations, Hippocampal,Hippocampal Formations,Hippocampus Propers,Horn, Ammon,Horn, Ammon's,Proper, Hippocampus,Propers, Hippocampus,Subiculums
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
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
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus