Patch-clamp recording of amino acid-activated responses in "organotypic" slice cultures.
Patch-clamp recording techniques were used to study the properties of amino acid-activated channels in cultured "organotypic" slices from rat cerebellum and hippocampus. Hippocampal pyramidal cells responded to the three main glutamatergic agonists, N-methyl-D-aspartate (N-Me-D-Asp), quisqualate, and kainate, whereas Purkinje cells responded only to quisqualate and kainate. Analysis of single-channel events recorded in outside-out patches from hippocampal neurons showed large conductance events (50 pS), which occurred more frequently in the presence of glycine. These events could be produced by N-Me-D-Asp and also, at low frequency, by quisqualate. On the other hand, 50-pS events were never observed in Purkinje neurons. This supports the hypothesis that N-Me-D-Asp and "non-N-Me-D-Asp" receptors are distinct molecular entities. Comparison of whole-cell and outside-out patch recordings from Purkinje cells revealed a clear spatial segregation of gamma-aminobutyric acid (GABA) and glutamate receptors: although GABA receptors are found at high density in somatic membrane, quisqualate and kainate receptors are mostly extrasomatic. The results show that organotypic slice cultures are amenable to patch-clamp methods. They also show that, in these cultures, amino acids receptors have specific distribution patterns according to cell type and to region within a cell.
Llano
I
I
Laboratoire de Neurobiologie, Ecole Normale Supérieure, Paris, France.
Marty
A
A
Johnson
J W
JW
Ascher
P
P
Gähwiler
B H
BH
D000200:Action Potentials; D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D003712:Dendrites / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects*; D007608:Kainic Acid / Q000494:pharmacology; D009924:Organ Culture Techniques; D011689:Purkinje Cells / Q000187:drug effects*; D051381:Rats; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter / Q000378:metabolism
D000596:Amino Acids; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; D007608:Kainic Acid