Biomaterial Database

Septotemporal distribution of entorhinal projections to the hippocampus in the cat: electrophysiological evidence. 1985

T Van Groen, and F H Lopes da Silva

The projection of the entorhinal cortex (EA) to the hippocampus in the cat has been studied by electrophysiological methods. Field potentials elicited by EA stimulation sites were measured in the hippocampus (fascia dentata). Different topographic distributions of the amplitude and of the onset latency of average evoked potentials (AEPs) were obtained depending on the place of the stimulation along a lateromedial axis in the Ea. The lateral EA elicited the largest AEPs in the septal part of the hippocampus and the medial EA evoked maximal responses in the temporal part of the hippocampus, while the intermediate part of the EA evoked the largest AEPs in the splenial (intermediate) part of the hippocampus. Unit activity elicited by hippocampal stimulation was measured in the EA. Analysis of the antidromic unit activity showed that the pathways analysed were monosynaptic. Different conduction velocities to the septal part of the hippocampus were found; the pathway from the lateral EA was the fastest and the pathway from the medial EA the slowest. Assuming that the sites of maximal AEP amplitude correspond to the location of the major synaptic inputs, it can be concluded that the active synaptic inputs arising along a latero-medial axis in the EA are distributed within the hippocampus according to a septotemporal axis, although with some overlap between the different projections. Therefore it may be concluded that the hippocampus is not homogeneous with respect to the inputs from the EA. The present observations are discussed regarding anatomical data and putative functional differences between septal and temporal hippocampus.

UI	MeSH Term	Description	Entries
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
D002540	Cerebral Cortex	The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.	Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical
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
D005071	Evoked Potentials	Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.	Event Related Potential,Event-Related Potentials,Evoked Potential,N100 Evoked Potential,P50 Evoked Potential,N1 Wave,N100 Evoked Potentials,N2 Wave,N200 Evoked Potentials,N3 Wave,N300 Evoked Potentials,N4 Wave,N400 Evoked Potentials,P2 Wave,P200 Evoked Potentials,P50 Evoked Potentials,P50 Wave,P600 Evoked Potentials,Potentials, Event-Related,Event Related Potentials,Event-Related Potential,Evoked Potential, N100,Evoked Potential, N200,Evoked Potential, N300,Evoked Potential, N400,Evoked Potential, P200,Evoked Potential, P50,Evoked Potential, P600,Evoked Potentials, N100,Evoked Potentials, N200,Evoked Potentials, N300,Evoked Potentials, N400,Evoked Potentials, P200,Evoked Potentials, P50,Evoked Potentials, P600,N1 Waves,N2 Waves,N200 Evoked Potential,N3 Waves,N300 Evoked Potential,N4 Waves,N400 Evoked Potential,P2 Waves,P200 Evoked Potential,P50 Waves,P600 Evoked Potential,Potential, Event Related,Potential, Event-Related,Potential, Evoked,Potentials, Event Related,Potentials, Evoked,Potentials, N400 Evoked,Related Potential, Event,Related Potentials, Event,Wave, N1,Wave, N2,Wave, N3,Wave, N4,Wave, P2,Wave, P50,Waves, N1,Waves, N2,Waves, N3,Waves, N4,Waves, P2,Waves, P50
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
D000344	Afferent Pathways	Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.	Afferent Pathway,Pathway, Afferent,Pathways, Afferent
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
D013702	Temporal Lobe	Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the OCCIPITAL LOBE.	Anterior Temporal Lobe,Brodmann Area 20,Brodmann Area 21,Brodmann Area 22,Brodmann Area 37,Brodmann Area 38,Brodmann Area 52,Brodmann's Area 20,Brodmann's Area 21,Brodmann's Area 22,Brodmann's Area 37,Brodmann's Area 38,Brodmann's Area 52,Inferior Temporal Gyrus,Middle Temporal Gyrus,Parainsular Area,Fusiform Gyrus,Gyrus Fusiformis,Gyrus Temporalis Superior,Inferior Horn of Lateral Ventricle,Inferior Horn of the Lateral Ventricle,Lateral Occipito-Temporal Gyrus,Lateral Occipitotemporal Gyrus,Occipitotemporal Gyrus,Planum Polare,Superior Temporal Gyrus,Temporal Cortex,Temporal Gyrus,Temporal Horn,Temporal Horn of the Lateral Ventricle,Temporal Operculum,Temporal Region,Temporal Sulcus,Anterior Temporal Lobes,Area 20, Brodmann,Area 20, Brodmann's,Area 21, Brodmann,Area 21, Brodmann's,Area 22, Brodmann,Area 22, Brodmann's,Area 37, Brodmann,Area 37, Brodmann's,Area 38, Brodmann,Area 38, Brodmann's,Area 52, Brodmann,Area 52, Brodmann's,Area, Parainsular,Areas, Parainsular,Brodmanns Area 20,Brodmanns Area 21,Brodmanns Area 22,Brodmanns Area 37,Brodmanns Area 38,Brodmanns Area 52,Cortex, Temporal,Gyrus, Fusiform,Gyrus, Inferior Temporal,Gyrus, Lateral Occipito-Temporal,Gyrus, Lateral Occipitotemporal,Gyrus, Middle Temporal,Gyrus, Occipitotemporal,Gyrus, Superior Temporal,Gyrus, Temporal,Horn, Temporal,Lateral Occipito Temporal Gyrus,Lobe, Anterior Temporal,Lobe, Temporal,Occipito-Temporal Gyrus, Lateral,Occipitotemporal Gyrus, Lateral,Operculum, Temporal,Parainsular Areas,Region, Temporal,Sulcus, Temporal,Temporal Cortices,Temporal Gyrus, Inferior,Temporal Gyrus, Middle,Temporal Gyrus, Superior,Temporal Horns,Temporal Lobe, Anterior,Temporal Lobes,Temporal Lobes, Anterior,Temporal Regions