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Neurotransmitters in the thalamus relaying visceral input to the insular cortex in the rat.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Barnabi, Francesco Cechetto, David F. |
| Copyright Year | 2001 |
| Abstract | Neurotransmitters relaying ascending visceral information were examined by comparing the response of neurons in the insular cortex to vagal stimulation (0.8 Hz, 2 mA) before and after neurotransmitter antagonist injections (200 nl) in the ventroposterior parvocellular nucleus of the thalamus (VPpc). Cobalt (10 mM; presynaptic blocker) and kynurenate (100 microM; nonspecific excitatory amino acid antagonist) injections in the VPpc resulted in an attenuation (73-100 and 38-98%, respectively) of the evoked cortical response. Injections of the specific N-methyl-D-aspartate (NMDA) antagonist DL-2-amino-5-phosphonopentanoic acid (200 microM and 2 mM) did not affect the vagally evoked response, whereas the nonspecific non-NMDA antagonist L-glutamic acid diethylester (200 microM) attenuated the vagally evoked response by 66-100%. Three concentrations of the DL-alpha-amino-3-hydroxy-5-methylisoxazole-propionic acid (AMPA)-specific antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (20 and 200 microM and 2 mM) attenuated the vagally evoked cortical response by 29 +/- 9, 31 +/- 10, and 59 +/- 8%, respectively. The more selective AMPA antagonist 6-nitro-7-sulphamoylbenzo(f)quinoxaline-2,3-dione (200 microM and 2 mM) inhibited the vagally evoked cortical response by 53 +/- 8 and 52 +/- 3%, respectively. Phentolamine (0.1 and 1.0 microM), a general alpha-adrenergic antagonist, and picrotoxin (0.1 and 1.0 microM), a GABA(A) antagonist, did not affect the vagally evoked response. Atropine, a muscarinic cholinergic antagonist, decreased the vagally evoked response by 40 +/- 2% at a concentration of 0.1 microM, but a higher concentration of 1.0 microM had no effect. These results indicate that the non-NMDA excitatory amino acid receptor is necessary for the relay of visceral information in the VPpc. Muscarinic receptors may modulate visceral neuronal excitability in the VPpc, although the exact interaction between the inhibitory (m2) and excitatory (m3 or m5) muscarinic receptor types found in the thalamus is not known. |
| Starting Page | 1 |
| Ending Page | 4 |
| Page Count | 4 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://ajpregu.physiology.org/content/ajpregu/281/5/R1665.full.pdf |
| PubMed reference number | 11641139v1 |
| Volume Number | 281 |
| Issue Number | 5 |
| Journal | American journal of physiology. Regulatory, integrative and comparative physiology |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Adrenergic Antagonists Adrenergic alpha-Antagonists Aspartic Acid Atropine Cell Nucleus Cerebral cortex Cholinergic Antagonists Cobalt Excitatory Amino Acids Fifty Nine Glutamic Acid Gonadotropin-Releasing Hormone Receptor Hertz (Hz) Insula of Reil Kynurenate M3 Mental Health Checklist M5 Additive/Preservative Muscarinic Acetylcholine Receptor Muscarinic Antagonists N-Methylaspartate Neurotransmitters Phentolamine Picrotoxin Propionic acid Receptors, Amino Acid Relay Device Component Thalamic structure gamma-Aminobutyric Acid neurotransmitter antagonist |
| Content Type | Text |
| Resource Type | Article |
