Biomaterial Database

Neuron addition in the postmetamorphic frog. 1992

P B Farel, and P G St Wecker, and S E Wray

Department of Physiology, School of Medicine, University of North Carolina, Chapel Hill 27599.

Neuron number among somatic motoneurons, sensory neurons, and sympathetic postganglionic neurons that innervate the hindlimb was correlated with body length in the bullfrog, Rana catesbeiana. Two to three times more dorsal root and sympathetic ganglion neurons are found in the largest than the smallest specimens. Hindlimb motoneurons show a 20% increase in number, but this increase is restricted to the caudal third of the motor pool. Within this region, 60% more motoneurons are found among the largest frogs. Cell division does not appear to be the mechanism of neuron addition. Instead, we propose that a pool of undifferentiated neurons mature to maintain functional capabilities as the animal increases in size.

UI	MeSH Term	Description	Entries
D008675	Metamorphosis, Biological	Profound physical changes during maturation of living organisms from the immature forms to the adult forms, such as from TADPOLES to frogs; caterpillars to BUTTERFLIES.	Biological Metamorphosis,Biological Metamorphoses,Metamorphoses, Biological
D009046	Motor Neurons	Neurons which activate MUSCLE CELLS.	Neurons, Motor,Alpha Motorneurons,Motoneurons,Motor Neurons, Alpha,Neurons, Alpha Motor,Alpha Motor Neuron,Alpha Motor Neurons,Alpha Motorneuron,Motoneuron,Motor Neuron,Motor Neuron, Alpha,Motorneuron, Alpha,Motorneurons, Alpha,Neuron, Alpha Motor,Neuron, Motor
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
D009475	Neurons, Afferent	Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.	Afferent Neurons,Afferent Neuron,Neuron, Afferent
D011892	Rana catesbeiana	A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.	Bullfrog,Bullfrogs,Rana catesbeianas,catesbeiana, Rana
D002452	Cell Count	The number of CELLS of a specific kind, usually measured per unit volume or area of sample.	Cell Density,Cell Number,Cell Counts,Cell Densities,Cell Numbers,Count, Cell,Counts, Cell,Densities, Cell,Density, Cell,Number, Cell,Numbers, Cell
D002455	Cell Division	The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.	M Phase,Cell Division Phase,Cell Divisions,Division Phase, Cell,Division, Cell,Divisions, Cell,M Phases,Phase, Cell Division,Phase, M,Phases, M
D006614	Hindlimb	Either of two extremities of four-footed non-primate land animals. It usually consists of a FEMUR; TIBIA; and FIBULA; tarsals; METATARSALS; and TOES. (From Storer et al., General Zoology, 6th ed, p73)	Hindlimbs
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
D013564	Sympathetic Nervous System	The thoracolumbar division of the autonomic nervous system. Sympathetic preganglionic fibers originate in neurons of the intermediolateral column of the spinal cord and project to the paravertebral and prevertebral ganglia, which in turn project to target organs. The sympathetic nervous system mediates the body's response to stressful situations, i.e., the fight or flight reactions. It often acts reciprocally to the parasympathetic system.	Nervous System, Sympathetic,Nervous Systems, Sympathetic,Sympathetic Nervous Systems,System, Sympathetic Nervous,Systems, Sympathetic Nervous