Biomaterial Database

Localization of spinal motor neurons supplying single ventral roots. 1980

J F Lane, and J F Hindson

The spinal cord location of motor neurons whose axons make up lumbar ventral roots L-5, L-6, and L-7 was investigated in the cat. Location was based on recording the extracellular action potentials from spinal motor neurons which had been activated antidromically by electrical stimulation of single ventral roots. The borders of the spinal segments (as defined by the rostral and caudal limits of the ventral root exit zone) and the sites recorded from were suitably marked, so that the territory occupied by the responding motor neurons could be determined. We showed that probably more certain localization of motor neurons could be achieved by using the positive polarity ("injury") antidromic responses which are recorded with needle electrodes of relatively large tip size. Negative polarity antidromic responses are recorded with fine-tipped electrodes. Results indicated that the origin of a single lumbar ventral root is from homolateral ventral horn cells and is mainly unisegmental, that is, from cells located within the segment of the root's attachment. There was, however, evidence of overlap of some motor cell bodies and/or dendritic processes into the caudal one-fourth of the adjacent more rostral segment. No difference was seen in the longitudinal extent of spinal motor cells supplying axons to the dorsal or ventral primary rami.

UI	MeSH Term	Description	Entries
D008159	Lumbar Vertebrae	VERTEBRAE in the region of the lower BACK below the THORACIC VERTEBRAE and above the SACRAL VERTEBRAE.	Vertebrae, Lumbar
D008839	Microelectrodes	Electrodes with an extremely small tip, used in a voltage clamp or other apparatus to stimulate or record bioelectric potentials of single cells intracellularly or extracellularly. (Dorland, 28th ed)	Electrodes, Miniaturized,Electrode, Miniaturized,Microelectrode,Miniaturized Electrode,Miniaturized Electrodes
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
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
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D006652	Histological Techniques	Methods of preparing tissue for examination and study of the origin, structure, function, or pathology.	Histologic Technic,Histologic Technics,Histologic Technique,Histologic Techniques,Histological Technics,Technic, Histologic,Technics, Histologic,Technique, Histologic,Techniques, Histologic,Histological Technic,Histological Technique,Technic, Histological,Technics, Histological,Technique, Histological,Techniques, Histological
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
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
D000870	Anterior Horn Cells	MOTOR NEURONS in the anterior (ventral) horn of the SPINAL CORD which project to SKELETAL MUSCLES.	Anterior Horn Neurons,Neurons, Anterior Horn,Neurons, Ventral Horn,Ventral Horn Cells,Ventral Horn Neurons,Anterior Horn Cell,Anterior Horn Neuron,Cell, Anterior Horn,Cell, Ventral Horn,Cells, Anterior Horn,Cells, Ventral Horn,Neuron, Anterior Horn,Neuron, Ventral Horn,Ventral Horn Cell,Ventral Horn Neuron
D013126	Spinal Nerve Roots	Paired bundles of NERVE FIBERS entering and leaving the SPINAL CORD at each segment. The dorsal and ventral nerve roots join to form the mixed segmental spinal nerves. The dorsal roots are generally afferent, formed by the central projections of the spinal (dorsal root) ganglia sensory cells, and the ventral roots are efferent, comprising the axons of spinal motor and PREGANGLIONIC AUTONOMIC FIBERS.	Dorsal Roots,Spinal Roots,Ventral Roots,Dorsal Root,Nerve Root, Spinal,Nerve Roots, Spinal,Root, Dorsal,Root, Spinal,Root, Spinal Nerve,Root, Ventral,Roots, Dorsal,Roots, Spinal,Roots, Spinal Nerve,Roots, Ventral,Spinal Nerve Root,Spinal Root,Ventral Root