Biomaterial Database

Hippocampal afferents to the rat prefrontal cortex: synaptic targets and relation to dopamine terminals. 1996

D B Carr, and S R Sesack

Department of Neuroscience, University of Pittsburgh, Pennsylvania 15260, USA.

Afferents to the prefrontal cortex (PFC) from the hippocampal formation and from midbrain dopamine (DA) neurons have been implicated in the cognitive and adaptive functions of this cortical region. In the present study, we investigated the ultrastructure and synaptic targets of hippocampal terminals, as well as their relation to DA terminals within the PFC of adult rats. Hippocampal afferents were labeled either by anterograde transport of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) from the ventral hippocampal formation or by anterograde degeneration following fimbria lesion. Hippocampal terminals in the PFC, identified by either method, formed primarily asymmetric axospinous synapses, with a small percentage forming asymmetric axodendritic synapses. Dopamine terminals in the PFC were identified by peroxidase immunocytochemistry for either tyrosine hydroxylase or DA and formed primarily symmetric synapses onto dendritic spines and small caliber dendritic shafts. Spines that received symmetric synaptic contact from DA terminals invariably also received an asymmetric synapse from an unlabeled terminal, forming a triadic complex. Hippocampal and DA terminals in the PFC were not often observed in the same area of the neuropil, and no examples of convergence of hippocampal and DA terminals onto common postsynaptic targets were observed. Further analysis revealed that spines receiving synaptic contact from hippocampal terminals did not receive additional synaptic contact from any other source. However, when localized to the same area of the neuropil, hippocampal and DA terminals were often in direct apposition to one another, without forming axo-axonic synapses. These results suggest that 1) hippocampal terminals primarily form excitatory synapses onto spiny pyramidal neurons, 2) hippocampal afferents are unlikely to be synaptically modulated by DA or non-DA terminals at the level of the dendritic spine, and 3) appositions between hippocampal and DA terminals may facilitate presynaptic interactions between these afferents to the PFC.

UI	MeSH Term	Description	Entries
D007124	Immunoenzyme Techniques	Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.	Antibody Enzyme Technique, Unlabeled,Enzyme Immunoassay,Enzyme-Labeled Antibody Technique,Immunoassay, Enzyme,Immunoperoxidase Techniques,Peroxidase-Antiperoxidase Complex Technique,Peroxidase-Labeled Antibody Technique,Antibody Enzyme Technic, Unlabeled,Enzyme-Labeled Antibody Technic,Immunoenzyme Technics,Immunoperoxidase Technics,Peroxidase-Antiperoxidase Complex Technic,Peroxidase-Labeled Antibody Technic,Antibody Technic, Enzyme-Labeled,Antibody Technic, Peroxidase-Labeled,Antibody Technics, Enzyme-Labeled,Antibody Technics, Peroxidase-Labeled,Antibody Technique, Enzyme-Labeled,Antibody Technique, Peroxidase-Labeled,Antibody Techniques, Enzyme-Labeled,Antibody Techniques, Peroxidase-Labeled,Enzyme Immunoassays,Enzyme Labeled Antibody Technic,Enzyme Labeled Antibody Technique,Enzyme-Labeled Antibody Technics,Enzyme-Labeled Antibody Techniques,Immunoassays, Enzyme,Immunoenzyme Technic,Immunoenzyme Technique,Immunoperoxidase Technic,Immunoperoxidase Technique,Peroxidase Antiperoxidase Complex Technic,Peroxidase Antiperoxidase Complex Technique,Peroxidase Labeled Antibody Technic,Peroxidase Labeled Antibody Technique,Peroxidase-Antiperoxidase Complex Technics,Peroxidase-Antiperoxidase Complex Techniques,Peroxidase-Labeled Antibody Technics,Peroxidase-Labeled Antibody Techniques,Technic, Enzyme-Labeled Antibody,Technic, Immunoenzyme,Technic, Immunoperoxidase,Technic, Peroxidase-Antiperoxidase Complex,Technic, Peroxidase-Labeled Antibody,Technics, Enzyme-Labeled Antibody,Technics, Immunoenzyme,Technics, Immunoperoxidase,Technics, Peroxidase-Antiperoxidase Complex,Technics, Peroxidase-Labeled Antibody,Technique, Enzyme-Labeled Antibody,Technique, Immunoenzyme,Technique, Immunoperoxidase,Technique, Peroxidase-Antiperoxidase Complex,Technique, Peroxidase-Labeled Antibody,Techniques, Enzyme-Labeled Antibody,Techniques, Immunoenzyme,Techniques, Immunoperoxidase,Techniques, Peroxidase-Antiperoxidase Complex,Techniques, Peroxidase-Labeled Antibody
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
D009410	Nerve Degeneration	Loss of functional activity and trophic degeneration of nerve axons and their terminal arborizations following the destruction of their cells of origin or interruption of their continuity with these cells. The pathology is characteristic of neurodegenerative diseases. Often the process of nerve degeneration is studied in research on neuroanatomical localization and correlation of the neurophysiology of neural pathways.	Neuron Degeneration,Degeneration, Nerve,Degeneration, Neuron,Degenerations, Nerve,Degenerations, Neuron,Nerve Degenerations,Neuron Degenerations
D009411	Nerve Endings	Branch-like terminations of NERVE FIBERS, sensory or motor NEURONS. Endings of sensory neurons are the beginnings of afferent pathway to the CENTRAL NERVOUS SYSTEM. Endings of motor neurons are the terminals of axons at the muscle cells. Nerve endings which release neurotransmitters are called PRESYNAPTIC TERMINALS.	Ending, Nerve,Endings, Nerve,Nerve Ending
D009714	Nucleus Accumbens	Collection of pleomorphic cells in the caudal part of the anterior horn of the LATERAL VENTRICLE, in the region of the OLFACTORY TUBERCLE, lying between the head of the CAUDATE NUCLEUS and the ANTERIOR PERFORATED SUBSTANCE. It is part of the so-called VENTRAL STRIATUM, a composite structure considered part of the BASAL GANGLIA.	Accumbens Nucleus,Nucleus Accumbens Septi,Accumbens Septi, Nucleus,Accumbens Septus, Nucleus,Accumbens, Nucleus,Nucleus Accumbens Septus,Nucleus, Accumbens,Septi, Nucleus Accumbens,Septus, Nucleus Accumbens
D004298	Dopamine	One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.	Hydroxytyramine,3,4-Dihydroxyphenethylamine,4-(2-Aminoethyl)-1,2-benzenediol,Dopamine Hydrochloride,Intropin,3,4 Dihydroxyphenethylamine,Hydrochloride, Dopamine
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
D006735	Horseradish Peroxidase	An enzyme isolated from horseradish which is able to act as an antigen. It is frequently used as a histochemical tracer for light and electron microscopy. Its antigenicity has permitted its use as a combined antigen and marker in experimental immunology.	Alpha-Peroxidase,Ferrihorseradish Peroxidase,Horseradish Peroxidase II,Horseradish Peroxidase III,Alpha Peroxidase,II, Horseradish Peroxidase,III, Horseradish Peroxidase,Peroxidase II, Horseradish,Peroxidase III, Horseradish,Peroxidase, Ferrihorseradish,Peroxidase, Horseradish
D000344	Afferent Pathways	Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.	Afferent Pathway,Pathway, Afferent,Pathways, Afferent