Biomaterial Database

Morphology and organization of axon collaterals from afferent fibres of slowly adapting type I units in cat spinal cord. 1978

A G Brown, and P K Rose, and P J Snow

1. The morphology of the collaterals of single axons innervating Type I slowly adapting receptors was studied by using the intra-axonal injection of the enzyme horseradish peroxidase in anaesthetized cats. The axons were impaled near their dorsal root entrance zone in the lumbosacral cord. The morphology was revealed by subsequent histochemistry. 2. Thirteen Type I axons were stained, nine with receptors in the hairy skin and four with receptors in the glabrous foot pad skin. Twelve axons could be traced back into their dorsal roots and 11 of these divided into rostral and caudal branches shortly after entering the spinal cord. 3. One hundred and twelve collaterals were given off the thirteen axons and all well filled collaterals had a similar morphology. In the dorsal horn they gave rise to wide elliptical areas of terminal arborization (in transverse sections of cord) that were limited to laminae III, IV and the dorsal part of lamina V. The terminal arborizations of collaterals from the same axon were in line in the saggittal plane, but only rarely did the terminal arborizations of adjacent collaterals overlap; usually there was a gap between adjacent terminal arborizations. 4. Synaptic boutons of Type I units from hairy skin were mainly of the "en passant" variety whereas those of Type I units from glabrous skin were generally "boutons terminaux" with very few boutons "de passage". 5. The morphology of axon collaterals of Type I units is compared with that of hair follicle units.

UI	MeSH Term	Description	Entries
D009475	Neurons, Afferent	Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.	Afferent Neurons,Afferent Neuron,Neuron, Afferent
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
D006197	Hair	A filament-like structure consisting of a shaft which projects to the surface of the SKIN from a root which is softer than the shaft and lodges in the cavity of a HAIR FOLLICLE. It is found on most surfaces of the body.	Fetal Hair,Hair, Fetal,Lanugo,Fetal Hairs,Hairs,Hairs, Fetal
D006651	Histocytochemistry	Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.	Cytochemistry
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
D001369	Axons	Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.	Axon
D012867	Skin	The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.
D013116	Spinal Cord	A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.	Coccygeal Cord,Conus Medullaris,Conus Terminalis,Lumbar Cord,Medulla Spinalis,Myelon,Sacral Cord,Thoracic Cord,Coccygeal Cords,Conus Medullari,Conus Terminali,Cord, Coccygeal,Cord, Lumbar,Cord, Sacral,Cord, Spinal,Cord, Thoracic,Cords, Coccygeal,Cords, Lumbar,Cords, Sacral,Cords, Spinal,Cords, Thoracic,Lumbar Cords,Medulla Spinali,Medullari, Conus,Medullaris, Conus,Myelons,Sacral Cords,Spinal Cords,Spinali, Medulla,Spinalis, Medulla,Terminali, Conus,Terminalis, Conus,Thoracic Cords
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