Effect of Amiloride on Gustatory Responses in the Ventroposteromedial Nucleus of the Thalamus in Rats
| Autor: | Thomas R. Scott, Barbara K. Giza, Justus V. Verhagen |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Male
Sucrose medicine.medical_specialty Physiology Sodium Thalamus Action Potentials chemistry.chemical_element Sodium Chloride Amiloride Sex Factors Sodium channel blocker Tongue Internal medicine medicine Animals Cluster Analysis Drug Interactions Rats Wistar Receptor Neurons Dose-Response Relationship Drug Chemistry General Neuroscience Solitary tract Adaptation Physiological Stimulation Chemical Rats medicine.anatomical_structure Endocrinology nervous system Taste Thalamic Nuclei Female Neuron Nucleus Neuroscience Sodium Channel Blockers medicine.drug |
| Zdroj: | Journal of Neurophysiology. 93:157-166 |
| ISSN: | 1522-1598 0022-3077 |
| DOI: | 10.1152/jn.00823.2003 |
| Popis: | The existence of gustatory neuron types has been demonstrated in the chorda tympani nerve and the nucleus of the solitary tract (NTS) of rats and hamsters through the oral application of amiloride, a sodium channel blocker. At these lower-order levels, amiloride was shown to reduce the response to sodium and lithium salts in sodium- and sugar-oriented cells, while leaving those of acid- and quinine-oriented neurons unmodified. We extended this investigation to higher-order levels by determining whether amiloride suppressed the responses of cells at the 4th-order gustatory relay in the thalamus, which neurons were affected, the degree of suppression, and whether the subsequent neural code for sodium was altered. We stimulated the whole oral cavity of anesthetized rats with a variety of tastants while recording the responses of 42 single thalamic neurons before and after the application of amiloride. The results revealed a similar pattern to that reported in the NTS. Amiloride inhibited only sodium- and sugar-oriented neurons, and specifically their responses to sodium- or lithium-containing stimuli. Moreover, there was a significant relationship between the degree of sodium specificity of a neuron and its sensitivity to inhibition by amiloride. These results demonstrate a relationship between a cell's response profile and its susceptibility to amiloride, and so offer evidence that gustatory neuron types exist through the level of the thalamus in rats. Thus membership in a neuronal group retains functional significance based on a receptor event 4 synapses away. |
| Databáze: | OpenAIRE |
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