Neuroscience letters
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Neuroscience letters · Jul 1997
The decreased susceptibility to the development of in vitro kindling-like state in hippocampal CA1 slices of rats sensitive to audiogenic seizures.
The field excitatory postsynaptic potential (fEPSP) with the presynaptic fiber volley (PrV) and the population spike (PS) were recorded with two glass microelectrodes in stratum radiatum and stratum pyramidale of rat hippocampal CA1 slices, respectively, in response to electric stimulation of Schaffer collaterals/commissural fibers (SC/CF) containing glutamate as a neurotransmitter. Three components of the overall input-output function were taken: (1) PrV amplitude vs. intensity of stimulating current, (2) dendritic layer fEPSP slope vs. PrV amplitude and (3) PS amplitude vs. fEPSP slope. ⋯ Such short-term [K+]o increases also did not induce the EPSP-spike transfer potentiation (E-S potentiation) in CA1 pyramidal neurons of audiogenic rats either. Furthermore, the presynaptic glutamatergic fibers of GPAS rats are less excitable to stimulating currents then that of normal Wistar rats. It is suggested that the resistance of audiogenic rat hippocampal CAI slices to the development of long lasting epileptiform activity is a protective adaptive mechanism preventing the propagation of seizure activity into limbic structures.
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Neuroscience letters · Jul 1997
Destruction of neurokinin-1 receptor expressing cells in vitro and in vivo using substance P-saporin in rats.
Substance P (SP) acts on neurons through the neurokinin-1 (NK-1) receptor. Conjugation of SP to the ribosome inactivating protein, saporin (SAP), produces a cytotoxin selective for cells that express the NK-1 receptor. ⋯ Injection of SP-SAP into the striatum selectively destroyed NK-1 receptor expressing interneurons. These results show that SP-SAP will be useful for studying the function of NK-1 receptor expressing neurons.