Biomaterial Database

Hippocampal CA1 kindling but not long-term potentiation disrupts spatial memory performance. 2006

L Stan Leung, and Bixia Shen

Department of Physiology, The University of Western Ontario, London, Canada N6A 5C1. sleung@uwo.ca

Long-term synaptic enhancement in the hippocampus has been suggested to cause deficits in spatial performance. Synaptic enhancement has been reported after hippocampal kindling that induced repeated electrographic seizures or afterdischarges (ADs) and after long-term potentiation (LTP) defined as synaptic enhancement without ADs. We studied whether repeated stimulations that gave LTP or ADs resulted in spatial performance deficits on the radial arm maze (RAM) and investigated the minimal number of ADs required for such deficits. Three experimental groups were run as follows: (1) 5 hippocampal ADs in 1 d (5-AD group), (2) 10 hippocampal ADs in 2 d (10-AD group), and (3) 12 -frequency primed-burst stimulations (PBSs) in 2 d in order to induce LTP without ADs (LTP group). Each experimental group was run together with a control group during the same time period. Rats were first trained in a spatial task on a radial arm maze with four of the eight arms baited, then given control or experimental treatment, and maze performance was tested in the first week (1-4 d) and fourth week (22-25 d) after treatment. Basal dendritic population excitatory postsynaptic potentials (pEPSPs) and medial perforant path (MPP)-evoked dentate gyrus population spike and polysynaptic CA1 excitation were recorded before and after experimental and control treatment. Spatial memory errors, in particular reference memory errors, were significantly higher in the 10-AD kindled group than any other group on the first and fourth week after treatment. Spatial memory errors were not significantly different in the 5-AD and LTP groups as compared with any control groups at any time. Basal dendritic pEPSP in CA1 was enhanced for about 1 wk after 12 PBSs, 10 ADs, or 5 ADs, while the dentate gyrus population spike and CA1 polysynaptic excitation evoked by MPP was increased for up to 4 wk after 10 ADs, but not 12 PBSs. Thus, distributed alteration of multiple synaptic transmission in the entorhinal-hippocampal circuit, but not LTP at the basal dendritic synapses in CA1, may disrupt spatial performance after 10 hippocampal ADs.

UI	MeSH Term	Description	Entries
D007696	Kindling, Neurologic	The repeated weak excitation of brain structures, that progressively increases sensitivity to the same stimulation. Over time, this can lower the threshold required to trigger seizures.	Kindlings, Neurologic,Neurologic Kindling,Neurologic Kindlings
D008297	Male		Males
D009435	Synaptic Transmission	The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.	Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
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
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
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
D012640	Seizures	Clinical or subclinical disturbances of cortical function due to a sudden, abnormal, excessive, and disorganized discharge of brain cells. Clinical manifestations include abnormal motor, sensory and psychic phenomena. Recurrent seizures are usually referred to as EPILEPSY or "seizure disorder."	Absence Seizure,Absence Seizures,Atonic Absence Seizure,Atonic Seizure,Clonic Seizure,Complex Partial Seizure,Convulsion,Convulsions,Convulsive Seizure,Convulsive Seizures,Epileptic Seizure,Epileptic Seizures,Generalized Absence Seizure,Generalized Tonic-Clonic Seizures,Jacksonian Seizure,Myoclonic Seizure,Non-Epileptic Seizure,Nonepileptic Seizure,Partial Seizure,Seizure,Seizures, Convulsive,Seizures, Focal,Seizures, Generalized,Seizures, Motor,Seizures, Sensory,Tonic Clonic Seizure,Tonic Seizure,Tonic-Clonic Seizure,Atonic Absence Seizures,Atonic Seizures,Clonic Seizures,Complex Partial Seizures,Convulsion, Non-Epileptic,Generalized Absence Seizures,Myoclonic Seizures,Non-Epileptic Seizures,Nonepileptic Seizures,Partial Seizures,Petit Mal Convulsion,Seizures, Auditory,Seizures, Clonic,Seizures, Epileptic,Seizures, Gustatory,Seizures, Olfactory,Seizures, Somatosensory,Seizures, Tonic,Seizures, Tonic-Clonic,Seizures, Vertiginous,Seizures, Vestibular,Seizures, Visual,Single Seizure,Tonic Seizures,Tonic-Clonic Seizures,Absence Seizure, Atonic,Absence Seizure, Generalized,Absence Seizures, Atonic,Absence Seizures, Generalized,Auditory Seizure,Auditory Seizures,Clonic Seizure, Tonic,Clonic Seizures, Tonic,Convulsion, Non Epileptic,Convulsion, Petit Mal,Convulsions, Non-Epileptic,Focal Seizure,Focal Seizures,Generalized Seizure,Generalized Seizures,Generalized Tonic Clonic Seizures,Generalized Tonic-Clonic Seizure,Gustatory Seizure,Gustatory Seizures,Motor Seizure,Motor Seizures,Non Epileptic Seizure,Non Epileptic Seizures,Non-Epileptic Convulsion,Non-Epileptic Convulsions,Olfactory Seizure,Olfactory Seizures,Partial Seizure, Complex,Partial Seizures, Complex,Seizure, Absence,Seizure, Atonic,Seizure, Atonic Absence,Seizure, Auditory,Seizure, Clonic,Seizure, Complex Partial,Seizure, Convulsive,Seizure, Epileptic,Seizure, Focal,Seizure, Generalized,Seizure, Generalized Absence,Seizure, Generalized Tonic-Clonic,Seizure, Gustatory,Seizure, Jacksonian,Seizure, Motor,Seizure, Myoclonic,Seizure, Non-Epileptic,Seizure, Nonepileptic,Seizure, Olfactory,Seizure, Partial,Seizure, Sensory,Seizure, Single,Seizure, Somatosensory,Seizure, Tonic,Seizure, Tonic Clonic,Seizure, Tonic-Clonic,Seizure, Vertiginous,Seizure, Vestibular,Seizure, Visual,Seizures, Generalized Tonic-Clonic,Seizures, Nonepileptic,Sensory Seizure,Sensory Seizures,Single Seizures,Somatosensory Seizure,Somatosensory Seizures,Tonic Clonic Seizures,Tonic-Clonic Seizure, Generalized,Tonic-Clonic Seizures, Generalized,Vertiginous Seizure,Vertiginous Seizures,Vestibular Seizure,Vestibular Seizures,Visual Seizure,Visual Seizures
D013037	Spatial Behavior	Reactions of an individual or groups of individuals with relation to the immediate surrounding area including the animate or inanimate objects within that area.	Behavior, Spatial,Behaviors, Spatial,Spatial Behaviors
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D017774	Long-Term Potentiation	A persistent increase in synaptic efficacy, usually induced by appropriate activation of the same synapses. The phenomenological properties of long-term potentiation suggest that it may be a cellular mechanism of learning and memory.	Long Term Potentiation,Long-Term Potentiations,Potentiation, Long-Term,Potentiations, Long-Term