Biomaterial Database

Analysis of excitatory synaptic action in pyramidal cells using whole-cell recording from rat hippocampal slices. 1990

S Hestrin, and R A Nicoll, and D J Perkel, and P Sah

Department of Physiology, University of California, San Francisco 94143.

1. The pharmacological and biophysical properties of excitatory synapses in the CA1 region of the hippocampus were studied using patch electrodes and whole-cell recording from thin slices. 2. Excitatory postsynaptic currents (EPSCs) had a fast component whose amplitude was voltage insensitive and a slow component whose amplitude was voltage dependent with a region of negative slope resistance in the range of -70 to -30 mV. 3. The voltage-dependent component was abolished by the N-methyl-D-aspartate (NMDA) receptor antagonist DL-2-amino-5-phosphonovalerate (APV; 50 microM), which had no effect on the fast component. Conversely, the fast voltage-insensitive component was abolished by the non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 10 microM) which had no effect on the slow component. 4. In Ringer solution with no added Mg2+ the current-voltage relation of the NMDA component was linear over a much larger voltage range than in the presence of 1.3 mM-Mg2+. 5. The NMDA component of the EPSC could be switched off with a hyperpolarizing voltage step at the soma. The kinetics of this switch-off was used to estimate the speed of clamp control of the subsynaptic membrane as well as the electrotonic distance from the soma. The kinetic analysis of the EPSC was restricted to synapses which were judged to be under adequate voltage control. 6. For those synapses that were close to the soma the time constant for decay for the non-NMDA component, which was voltage insensitive, ranged from 4-8 ms. 7. The rise time for the NMDA component was 8-20 ms and the time constant for decay ranged from 60-150 ms. 8. During increased transmitter release with post-tetanic potentiation or application or phorbol esters, both components of the EPSC increased to a similar extent. 9. These experiments provide a detailed description of the dual receptor mechanism operating at hippocampal excitatory synapses. In addition, the experiments provide an electrophysiological method for estimating the electrotonic distance of synaptic inputs.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
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
D010703	Phorbol Esters	Tumor-promoting compounds obtained from CROTON OIL (Croton tiglium). Some of these are used in cell biological experiments as activators of protein kinase C.	Phorbol Diester,Phorbol Ester,Phorbol Diesters,Diester, Phorbol,Diesters, Phorbol,Ester, Phorbol,Esters, Phorbol
D011712	Pyramidal Tracts	Fibers that arise from cells within the cerebral cortex, pass through the medullary pyramid, and descend in the spinal cord. Many authorities say the pyramidal tracts include both the corticospinal and corticobulbar tracts.	Corticobulbar Tracts,Corticospinal Tracts,Decussation, Pyramidal,Corticobulbar Tract,Corticospinal Tract,Pyramidal Decussation,Pyramidal Tract,Tract, Corticobulbar,Tract, Corticospinal,Tract, Pyramidal,Tracts, Corticobulbar,Tracts, Corticospinal,Tracts, Pyramidal
D011810	Quinoxalines		Quinoxaline
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
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
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
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