Serotonin 1A Receptors Alter Expression of Movement Representations
| Autor: | Michael C. Antle, A. Seto, R. W. McCarthy, J. T. G. Rodych, Stan T. Nakanishi, V. M. Smith, K. Scullion, Patrick J. Whelan, G. C. Teskey, Jeffery A. Boychuk, Quentin J. Pittman, Glenn R. Yamakawa |
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| Rok vydání: | 2013 |
| Předmět: |
Male
Agonist Serotonin Patch-Clamp Techniques Microinjections medicine.drug_class Movement 5 7-Dihydroxytryptamine Action Potentials Stimulation Tryptophan Hydroxylase Piperazines H-Reflex Mice Serotonin Agents Dorsal raphe nucleus Forelimb medicine Animals Rats Long-Evans Chromatography High Pressure Liquid Mice Knockout Neurons 8-Hydroxy-2-(di-n-propylamino)tetralin Analysis of Variance Brain Mapping Chemistry General Neuroscience Motor Cortex Articles Spinal cord Rats medicine.anatomical_structure Spinal Cord Receptor Serotonin 5-HT1A Excitatory postsynaptic potential Raphe Nuclei Pyramidal cell Neuroscience Psychomotor Performance |
| Zdroj: | The Journal of Neuroscience. 33:4988-4999 |
| ISSN: | 1529-2401 0270-6474 |
| Popis: | Serotonin has a myriad of central functions involving mood, appetite, sleep, and memory and while its release within the spinal cord is particularly important for generating movement, the corresponding role on cortical movement representations (motor maps) is unknown. Using adult rats we determined that pharmacological depletion of serotonin (5-HT) via intracerebroventricular administration of 5,7 dihydroxytryptamine resulted in altered movements of the forelimb in a skilled reaching task as well as higher movement thresholds and smaller maps derived using high-resolution intracortical microstimulation (ICMS). We ruled out the possibility that reduced spinal cord excitability could account for the serotonin depletion-induced changes as we observed an enhanced Hoffman reflex (H-reflex), indicating a hyperexcitable spinal cord. Motor maps derived in 5-HT1Areceptor knock-out mice also showed higher movement thresholds and smaller maps compared with wild-type controls. Direct cortical application of the 5-HT1A/7agonist 8-OH-DPAT lowered movement thresholdsin vivoand increased map size in 5-HT-depleted rats. In rats, electrical stimulation of the dorsal raphe lowered movement thresholds and this effect could be blocked by direct cortical application of the 5-HT1Aantagonist WAY-100135, indicating that serotonin is primarily acting through the 5-HT1Areceptor. Next we developed a novelin vitroICMS preparation that allowed us to track layer V pyramidal cell excitability. Bath application of WAY-100135 raised the ICMS current intensity to induce action potential firing whereas the agonist 8-OH-DPAT had the opposite effect. Together our results demonstrate that serotonin, acting through 5-HT1Areceptors, plays an excitatory role in forelimb motor map expression. |
| Databáze: | OpenAIRE |
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