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Effects of aminoglycoside antibiotics on the synaptic activity of rat hippocampal pyramidal cells
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Pharmacological Research, Vol. 22, Supplement 2, 1990
EFFECTS OF AMINOGLYCOSIDE ANTIBIOTICS ON THE SYNAPTIC ACTIVITY OF RAT HIPPOCAMPAL PYRAMIDAL CELLS. S.Sagratella, M.L.Proietti and A.Scotti de Carolis Pharmacology Department, Istituto Superiore di Sanita, Viale Regina Elena 299, 00161, Roma, Italy. It has been suggested that the inhibition of the transmitter release by aminoglycoside antibiotics in various peripheral nervous preparations depends on an influence of the drugs on calcium conduc tances. Binding studies have shown that these antibiotics are potent inhibitors of the N-type Omega-Conotoxin GVIA calcium channels in guinea-pig cerebral cortex membranes. In the present study the aminoglycoside antibiotics neomycin and streptomycin were tested on the synaptic activity of the CAl pyramidal neuron Schaffer collateral interconnections in rat hippocampal slices. Neomycin (0.5 mM) decreased the magnitude and shifted to the right the stimulus-response curve of the soma tic and dendritic exci ta tory pos tsynaptic potential (EPSP) and of the somatic population spike (PS). Streptomycin (1 mM) decreased the magnitude and shifted to the right the stimulus-response .c u r ve of the somatic and dendritic EPSP and of the somatic PS. High (+2 mM) calcium solutions were able to prevent the effects induced by the antibiotics and to shift to the left the stimulus-response curve of the 0.5 mM neomycin- and 1 mM streptomycin-treated hippocampal slices. The data demonstrate depressant effects of aminoglycoside antibiotics on central mammalian hippocampal synapses that may depend on an interference of the drugs on calcium conductances.
1043-661 8/90 /22110440-01/$03 .00/0
© 1990 The Italian Pharmacological Society
Pharmacological Research, Vol. 22, Supplement 2, 1990
EFFECTS OF AMINOGLYCOSIDE ANTIBIOTICS ON THE SYNAPTIC ACTIVITY OF RAT HIPPOCAMPAL PYRAMIDAL CELLS. S.Sagratella, M.L.Proietti and A.Scotti de Carolis Pharmacology Department, Istituto Superiore di Sanita, Viale Regina Elena 299, 00161, Roma, Italy. It has been suggested that the inhibition of the transmitter release by aminoglycoside antibiotics in various peripheral nervous preparations depends on an influence of the drugs on calcium conduc tances. Binding studies have shown that these antibiotics are potent inhibitors of the N-type Omega-Conotoxin GVIA calcium channels in guinea-pig cerebral cortex membranes. In the present study the aminoglycoside antibiotics neomycin and streptomycin were tested on the synaptic activity of the CAl pyramidal neuron Schaffer collateral interconnections in rat hippocampal slices. Neomycin (0.5 mM) decreased the magnitude and shifted to the right the stimulus-response curve of the soma tic and dendritic exci ta tory pos tsynaptic potential (EPSP) and of the somatic population spike (PS). Streptomycin (1 mM) decreased the magnitude and shifted to the right the stimulus-response .c u r ve of the somatic and dendritic EPSP and of the somatic PS. High (+2 mM) calcium solutions were able to prevent the effects induced by the antibiotics and to shift to the left the stimulus-response curve of the 0.5 mM neomycin- and 1 mM streptomycin-treated hippocampal slices. The data demonstrate depressant effects of aminoglycoside antibiotics on central mammalian hippocampal synapses that may depend on an interference of the drugs on calcium conductances.
1043-661 8/90 /22110440-01/$03 .00/0
© 1990 The Italian Pharmacological Society