Altered desensitization produces enhancement of EPSPs in neocortical neurons
| Autor: | M. R. Pelletier, John J. Hablitz |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Male
Physiology Glutamic Acid AMPA receptor Neurotransmission Benzothiadiazines Receptors N-Methyl-D-Aspartate Synaptic Transmission Membrane Potentials Rats Sprague-Dawley Culture Techniques medicine Animals Receptors AMPA Cerebral Cortex Neurons Membrane potential Neocortex Chemistry General Neuroscience Glutamate receptor Rats medicine.anatomical_structure 2-Amino-5-phosphonovalerate nervous system Excitatory postsynaptic potential Biophysics NMDA receptor Female Cyclothiazide Neuroscience medicine.drug |
| Zdroj: | Journal of Neurophysiology. 72:1032-1036 |
| ISSN: | 1522-1598 0022-3077 |
| DOI: | 10.1152/jn.1994.72.2.1032 |
| Popis: | 1. Neocortical brain slices were prepared from rats (35–50 days of age) and maintained in vitro. Intracellular recordings were obtained from neurons in cortical layers II/III. The effect of bath application of cyclothiazide (CYZ), a potent blocker of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor desensitization, on evoked synaptic activity and passive membrane properties was investigated. 2. Bath application of CYZ did not significantly affect resting membrane potential, input resistance, or repetitive firing. CYZ increased both the amplitude and duration of evoked excitatory postsynaptic potentials (EPSPs). Polysynaptic responses were also augumented. These effects persisted after the blockade of N-methyl-D-aspartate (NMDA) receptors with D-2-amino-5-phosphonovaleric acid (D-APV). The magnitude of these effects appeared to vary directly with stimulation intensity and presumably, amount of glutamate release. 3. Epileptiform activity was induced by bath application of bicuculline methiodide. The amplitude and duration of evoked paroxysmal discharges were increased by CYZ. Similar results were seen in presence of D-APV. 4. These results indicate that CYZ has significant effects on synaptic transmission. Desensitization of non-NMDA receptors may be an important mechanism for determining the time course of EPSPs and in curtailing epileptiform responses in the rat neocortex. |
| Databáze: | OpenAIRE |
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