Biomaterial Database

Synaptic relationships of serotonin-immunoreactive terminal baskets on GABA neurons in the cat auditory cortex. 1991

J DeFelipe, and S H Hendry, and T Hashikawa, and E G Jones

Department of Anatomy and Neurobiology, University of California, Irvine 92717.

Correlative light and electron microscopic immunocytochemical methods were used to analyze the 5-HT innervation of the primary auditory area (AI) of the cat cerebral cortex and to examine the synaptic relationships of 5-HT basket terminations on target neurons in that area. Three morphological types of 5-HT-immunoreactive fibers are present: type I, which is very thin and very finely beaded; type II, which is thin and coarsely beaded; and type III, which has a relatively thick main shaft and very few beads. Type I is the most abundant, type II is relatively less common, and type III is the least abundant type. The 3 types of fibers are present through the thickness of AI and in the subjacent white matter, but the densest plexus is found in layers I-III. One of the most characteristic features of type II fibers is that they commonly form small, dense clusters that resemble baskets apposed to the somata and primary dendrites of unstained neurons. The basket formations are more frequently found in layers I and II, and they vary in complexity. Simultaneous immunostaining for GABA and 5-HT reveals that many 5-HT baskets surround the somata and dendrites of GABA neurons. In 2-microns-thick plastic sections, each basket formation can be seen surrounding 1 or a group of 2 or 3 cells. In the latter case, one cell is much larger and at the electron microscope level is identified as a neuron, while the other cells are neuroglial cells. Reconstructions were made from serial electron micrographs of 135 5-HT-immunoreactive boutons. Of these boutons, 110 belonged to basket formations, 14 to type I axons located in the neuropil, and the remaining 11 to type II fibers located in the white matter. Only 4 of the 135 boutons made conventional synaptic contacts. These were of the asymmetrical type. Most of the boutons made very small, indistinct membrane specializations or none at all. The present results therefore suggest a strong interaction between 5-HT axon terminals and specific GABA neurons, which may be mediated by release sites that are not associated with morphologically distinct synaptic contacts.

UI	MeSH Term	Description	Entries
D007150	Immunohistochemistry	Histochemical localization of immunoreactive substances using labeled antibodies as reagents.	Immunocytochemistry,Immunogold Techniques,Immunogold-Silver Techniques,Immunohistocytochemistry,Immunolabeling Techniques,Immunogold Technics,Immunogold-Silver Technics,Immunolabeling Technics,Immunogold Silver Technics,Immunogold Silver Techniques,Immunogold Technic,Immunogold Technique,Immunogold-Silver Technic,Immunogold-Silver Technique,Immunolabeling Technic,Immunolabeling Technique,Technic, Immunogold,Technic, Immunogold-Silver,Technic, Immunolabeling,Technics, Immunogold,Technics, Immunogold-Silver,Technics, Immunolabeling,Technique, Immunogold,Technique, Immunogold-Silver,Technique, Immunolabeling,Techniques, Immunogold,Techniques, Immunogold-Silver,Techniques, Immunolabeling
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
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
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
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
D005260	Female		Females
D005680	gamma-Aminobutyric Acid	The most common inhibitory neurotransmitter in the central nervous system.	4-Aminobutyric Acid,GABA,4-Aminobutanoic Acid,Aminalon,Aminalone,Gammalon,Lithium GABA,gamma-Aminobutyric Acid, Calcium Salt (2:1),gamma-Aminobutyric Acid, Hydrochloride,gamma-Aminobutyric Acid, Monolithium Salt,gamma-Aminobutyric Acid, Monosodium Salt,gamma-Aminobutyric Acid, Zinc Salt (2:1),4 Aminobutanoic Acid,4 Aminobutyric Acid,Acid, Hydrochloride gamma-Aminobutyric,GABA, Lithium,Hydrochloride gamma-Aminobutyric Acid,gamma Aminobutyric Acid,gamma Aminobutyric Acid, Hydrochloride,gamma Aminobutyric Acid, Monolithium Salt,gamma Aminobutyric Acid, Monosodium Salt
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