Biomaterial Database

Morphogenesis of the mossy fiber synapses in the hippocampus of the rhesus monkey. 1986

V K Vijayan

Morphogenesis of the hippocampal mossy fiber synapses (MFSs) in fetal and postnatal rhesus monkeys was examined by electron microscopy. Typical invaginated MFSs were absent on gestation days 90 and 109 and were detected infrequently on day 132. In older fetuses and postnatal animals of 16 days and 9 months of age, the percentage of invaginated MFSs increased and the synapses exhibited increases in the number of invaginated spines and density of synaptic vesicles and greater maturity of the spines. At all ages, MFSs exhibited a wide range of maturity which may be correlated with the reported protracted generation of dentate granule cells in the rhesus monkey. The pattern of morphogenesis of MFSs in the monkey suggests that as in the rat, it is very likely that the mossy fibers contact pyramidal cells prior to the emergence of the 'thorny excrescences' and that this is followed by progressive maturation of the MFSs. The time-course of major morphogenetic modifications in MFSs in the rhesus monkey corresponds to the period of elaboration of complex spines and synapses in the dentate molecular layer. On this basis, it is suggested that these two processes are interrelated developmental events.

UI	MeSH Term	Description	Entries
D008253	Macaca mulatta	A species of the genus MACACA inhabiting India, China, and other parts of Asia. The species is used extensively in biomedical research and adapts very well to living with humans.	Chinese Rhesus Macaques,Macaca mulatta lasiota,Monkey, Rhesus,Rhesus Monkey,Rhesus Macaque,Chinese Rhesus Macaque,Macaca mulatta lasiotas,Macaque, Rhesus,Rhesus Macaque, Chinese,Rhesus Macaques,Rhesus Macaques, Chinese,Rhesus Monkeys
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
D009412	Nerve Fibers	Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM.	Cerebellar Mossy Fibers,Mossy Fibers, Cerebellar,Cerebellar Mossy Fiber,Mossy Fiber, Cerebellar,Nerve Fiber
D002470	Cell Survival	The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.	Cell Viability,Cell Viabilities,Survival, Cell,Viabilities, Cell,Viability, Cell
D005314	Embryonic and Fetal Development	Morphological and physiological development of EMBRYOS or FETUSES.	Embryo and Fetal Development,Prenatal Programming,Programming, Prenatal
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