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Kinetic properties of NMDA receptor-mediated synaptic currents in rat hippocampal pyramidal cells versus interneurones.
J Physiol. 1993 Jun; 465:223-44.JP

Abstract

1. Whole-cell tight-seal recordings were obtained from visually identified pyramidal cells (PCs) and interneurones (INs) in the CA1 field of thin hippocampal slices from 13- to 23-day-old rats. The INs sampled were classified according to their location either in the molecular layer (M-INs) or in the oriens layer and alveus (OA-INs). PCs and INs differed in their mode of firing when depolarized by a prolonged current pulse. Whereas PCs fired a single action potential, most INs responded with non-accommodating high frequency spike firing. 2. In the presence of 1 microM tetrodotoxin (TTX), bath application of either 50 microM L-glutamate with 10 microM 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) or 2.5 microM N-methyl-D-aspartate (NMDA), induced a similar conductance increase in PCs and INs that was completely blocked by 200 microM DL-2-amino-5-phosphonovaleric acid (APV). The NMDA receptor-mediated currents reversed around 4 mV and exhibited an area of negative slope conductance at potentials more negative than -20 to -30 mV in the presence of 1-2 mM Mg2+. 3. Dual-component excitatory postsynaptic currents (EPSCs) were evoked in PCs and INs by stimulating afferent fibres close to the neurone. The NMDA receptor-mediated component of the EPSCs (NMDA EPSC) was isolated by adding 10 microM CNQX to block non-NMDA receptors. The NMDA EPSCs in all cell types reversed around 1.5 mV and were abolished by 50 microM APV. 4. In saline containing 1 mM Mg2+, the peak current-voltage (I-V) relationship of NMDA EPSCs in PCs and INs showed an area of negative slope conductance at voltages more negative than -20 to -30 mV. In nominally Mg(2+)-free saline, the peak I-V relation was linear over a much wider voltage range in both cell types. 5. The 10-90% rise times of NMDA EPSCs at -60 mV ranged from 4.5 to 16 ms in PCs (mean 8.7 ms; n = 25) and in M-INs (mean 9.1 ms; n = 10). Their decay could be best fitted with the sum of two exponentials. The decay of NMDA EPSCs in PCs was significantly slower than that recorded in INs. The average fast (tau f) and slow (tau s) time constants of decay were, respectively, 66.5 and 353.9 ms in PCs, and 34.4 and 212.5 ms in M-INs.(

ABSTRACT

TRUNCATED AT 400 WORDS)

Authors+Show Affiliations

Department of Physiology, Hebrew University School of Medicine, Jerusalem, Israel.No affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

7901401

Citation

Perouansky, M, and Y Yaari. "Kinetic Properties of NMDA Receptor-mediated Synaptic Currents in Rat Hippocampal Pyramidal Cells Versus Interneurones." The Journal of Physiology, vol. 465, 1993, pp. 223-44.
Perouansky M, Yaari Y. Kinetic properties of NMDA receptor-mediated synaptic currents in rat hippocampal pyramidal cells versus interneurones. J Physiol. 1993;465:223-44.
Perouansky, M., & Yaari, Y. (1993). Kinetic properties of NMDA receptor-mediated synaptic currents in rat hippocampal pyramidal cells versus interneurones. The Journal of Physiology, 465, 223-44.
Perouansky M, Yaari Y. Kinetic Properties of NMDA Receptor-mediated Synaptic Currents in Rat Hippocampal Pyramidal Cells Versus Interneurones. J Physiol. 1993;465:223-44. PubMed PMID: 7901401.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Kinetic properties of NMDA receptor-mediated synaptic currents in rat hippocampal pyramidal cells versus interneurones. AU - Perouansky,M, AU - Yaari,Y, PY - 1993/6/1/pubmed PY - 1993/6/1/medline PY - 1993/6/1/entrez SP - 223 EP - 44 JF - The Journal of physiology JO - J Physiol VL - 465 N2 - 1. Whole-cell tight-seal recordings were obtained from visually identified pyramidal cells (PCs) and interneurones (INs) in the CA1 field of thin hippocampal slices from 13- to 23-day-old rats. The INs sampled were classified according to their location either in the molecular layer (M-INs) or in the oriens layer and alveus (OA-INs). PCs and INs differed in their mode of firing when depolarized by a prolonged current pulse. Whereas PCs fired a single action potential, most INs responded with non-accommodating high frequency spike firing. 2. In the presence of 1 microM tetrodotoxin (TTX), bath application of either 50 microM L-glutamate with 10 microM 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) or 2.5 microM N-methyl-D-aspartate (NMDA), induced a similar conductance increase in PCs and INs that was completely blocked by 200 microM DL-2-amino-5-phosphonovaleric acid (APV). The NMDA receptor-mediated currents reversed around 4 mV and exhibited an area of negative slope conductance at potentials more negative than -20 to -30 mV in the presence of 1-2 mM Mg2+. 3. Dual-component excitatory postsynaptic currents (EPSCs) were evoked in PCs and INs by stimulating afferent fibres close to the neurone. The NMDA receptor-mediated component of the EPSCs (NMDA EPSC) was isolated by adding 10 microM CNQX to block non-NMDA receptors. The NMDA EPSCs in all cell types reversed around 1.5 mV and were abolished by 50 microM APV. 4. In saline containing 1 mM Mg2+, the peak current-voltage (I-V) relationship of NMDA EPSCs in PCs and INs showed an area of negative slope conductance at voltages more negative than -20 to -30 mV. In nominally Mg(2+)-free saline, the peak I-V relation was linear over a much wider voltage range in both cell types. 5. The 10-90% rise times of NMDA EPSCs at -60 mV ranged from 4.5 to 16 ms in PCs (mean 8.7 ms; n = 25) and in M-INs (mean 9.1 ms; n = 10). Their decay could be best fitted with the sum of two exponentials. The decay of NMDA EPSCs in PCs was significantly slower than that recorded in INs. The average fast (tau f) and slow (tau s) time constants of decay were, respectively, 66.5 and 353.9 ms in PCs, and 34.4 and 212.5 ms in M-INs.(ABSTRACT TRUNCATED AT 400 WORDS) SN - 0022-3751 UR - https://www.unboundmedicine.com/medline/citation/7901401/Kinetic_properties_of_NMDA_receptor_mediated_synaptic_currents_in_rat_hippocampal_pyramidal_cells_versus_interneurones_ L2 - https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0022-3751&date=1993&volume=465&spage=223 DB - PRIME DP - Unbound Medicine ER -