Publicado 12 números por año
ISSN Imprimir: 1521-9437
ISSN En Línea: 1940-4344
Indexed in
Effects of Amanita Species Extracts on Neuron Responses in the Rat Hippocampal Stratum Pyramidal (CA1 Region) in Vitro
SINOPSIS
Spike responses of 31 pyramidal neurons from the CA1 zone in rat hippocampal slices were studied during the application of 1% extracts of five Amanita species (Amanita citrina (Schaeff.) S. F. Gray, A. muscaria (L.: Fr.) Hook., A. pantherina (DC: Fr.) Seer., A. phalloides (Vail.: Fr.) Seer., and A. rubescens (Pers.: Fr.) S. F. Gray). It was found that extracts of A. muscaria, A. pantherina and A. rubescens caused a long neuron excitation, sometimes for 9−30 min. On average, the neuron frequency of spike discharge increased five times during the application of A. muscaria and A. rubescens extracts and 10 times after the application of A. pantherina. Latency and duration of excitation caused by the extract application were 2−4 times longer than during L-glutamic acid application. The A. citrina extract application brought about a short excitation followed by a long inhibition of the spike activity. Neuronal inhibition (sometimes up to 13−15 min) resulted from the use of the A. citrina extract and newly prepared water extracts from A. muscaria. The latency and duration of excitation and time needed to reach a maximum response caused by an extract decreased in the order: A. rubescens> A. pantherina > A. muscaria> A. citrina. The same parameters for the inhibition reaction decreased in the order: A. citrina > A. muscaria. The A. phalloides extract hardly affected the neuron background spike activity but it inhibited the response to L-glutamic acid. The A. citrina extract also blocked the response to L-glutamic acid. The hippocampal neuron sensitivity to the substances (from the A. muscaria and A. pantherina extracts) blocking the glutamate transmission was different. After the extract application some neurons showed no changes in response to L-glutamic acid while in the others their responses were inhibited for tens of minutes. On the other hand the response to the A. muscaria and A. pantherina extracts decreased during the excitation caused by the L-glutamic acid application.