
The central nucleus of the amygdala (CeA) has been identified as a site of nociceptive processing important for sensitization induced by peripheral injury. However, the cellular signaling components underlying this function remain unknown. Here, we identify metabotropic glutamate receptor 5 (mGluR5) as an integral component of nociceptive processing in the CeA. Pharmacological activation of mGluRs with (R,S)-3,5-dihydroxyphenylglycine (DHPG) in the CeA of mice is sufficient to induce peripheral hypersensitivity in the absence of injury. DHPG-induced peripheral hypersensitivity is reduced via pharmacological blockade of mGluR5 or genetic disruption of mGluR5. Furthermore, pharmacological blockade or conditional deletion of mGluR5 in the CeA abrogates inflammation-induced hypersensitivity, demonstrating the necessity of mGluR5 in CeA-mediated pain modulation. Moreover, we demonstrate that phosphorylation of extracellular-signal regulated kinase 1/2 (ERK1/2) is downstream of mGluR5 activation in the CeA and is necessary for the full expression of peripheral inflammation-induced behavioral sensitization. Finally, we present evidence of right hemispheric lateralization of mGluR5 modulation of amygdalar nociceptive processing. We demonstrate that unilateral pharmacological activation of mGluR5 in the CeA produces distinct behavioral responses depending on whether the right or left amygdala is injected. We also demonstrate significantly higher levels of mGluR5 expression in the right amygdala compared with the left under baseline conditions, suggesting a potential mechanism for right hemispheric lateralization of amygdala function in pain processing. Together, these results establish an integral role for mGluR5 and ERK1/2 in nociceptive processing in the CeA.
Mice, Knockout, Analysis of Variance, Mitogen-Activated Protein Kinase 3, Pyridines, Green Fluorescent Proteins, Pain, Amygdala, Functional Laterality, Methoxyhydroxyphenylglycol, Mice, Inbred C57BL, Mice, Gene Expression Regulation, Hyperalgesia, Formaldehyde, Nitriles, Medicine and Health Sciences, Butadienes, Animals, Enzyme Inhibitors, Excitatory Amino Acid Antagonists, Pain Measurement
Mice, Knockout, Analysis of Variance, Mitogen-Activated Protein Kinase 3, Pyridines, Green Fluorescent Proteins, Pain, Amygdala, Functional Laterality, Methoxyhydroxyphenylglycol, Mice, Inbred C57BL, Mice, Gene Expression Regulation, Hyperalgesia, Formaldehyde, Nitriles, Medicine and Health Sciences, Butadienes, Animals, Enzyme Inhibitors, Excitatory Amino Acid Antagonists, Pain Measurement
| citations This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 114 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Top 10% | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Top 1% |
