ISSN:
1432-1106
Keywords:
Glutamate receptors
;
NMDA receptor
;
Olfactory cortex
;
DNQX
;
AP5
;
Rat
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The pharmacology of synaptic transmission was studied in slices of rat piriform cortex using the selective non-NMDA glutamate receptor antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX) and the selective NMDA receptor antagonist D-2-amino-5-phosphonopentanoate (D-AP5). DNQX produced a dose-dependent blockade of synaptic transmission at both lateral olfactory tract and associational system synapses with half-maximal effects at about 2.5 μM. D-AP5 had no significant effects on field potentials recorded in medium containing 2.5 mM Mg++. However in low Mg++ (100–200 μM) medium, D-AP5 did reduce a slow component of postsynaptic responses in both synaptic systems. In Mg++-free medium, 20 μM DNQX did not completely block transmission; the remaining response components were blocked by D-AP5. These results suggest that normal synaptic transmission in the two main inputs to the superficial layers of piriform cortex is mediated by non-NMDA receptors but that NMDA receptors can also participate under conditions where the Mg++ block of the NMDA channel is alleviated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00231264
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