BACKGROUND：Glutamate acid ionotropic receptor N-methyl-D-aspartic acid （NMDA） takes part in long-term potentiation, thereby influencing the process of learning and memory. OBJECTIVE： To verify expression of NMDA 2...BACKGROUND：Glutamate acid ionotropic receptor N-methyl-D-aspartic acid （NMDA） takes part in long-term potentiation, thereby influencing the process of learning and memory. OBJECTIVE： To verify expression of NMDA 2A/B and 2B receptors in the anterior thalamic nucleus and subiculum complex of rats. DESIGN, TIME AND SETTING： A single-sample observation was performed at Department of Anatomy in Dalian Medical University （Dalian, Liaoning, China） from April to September in 2007. MATERIALS： Ten adult Wistar rats were used for this study, as well as rabbit anti-NMDA 2A/B and 2B antibodies. METHODS： The rats were anesthetized and perfused, followed by brain resection and coronal sectioning of the brain tissue. A 1：3 series was selected for immunohistochemistry, using antibodies specific to NMDA 2A/B and 2B receptors. Photos were taken using the Nikon image analysis system. MAIN OUTCOME MEASURES： Expression and distribution of immunohistochemistry staining of NMDA 2A/B and 2B receptor subunits. RESULTS： There were a large number of NMDA 2A/B and 2B receptor-positive neurons distributed throughout the anterior dorsal thalamic nucleus. In the anterior ventral thalamic nucleus, distribution of positive neurons was rare, staining intensity was lighter, and cell bodies were smaller compared with the anterior dorsal thalamic nucleus. In the subiculum complex, staining intensity of NMDA 2A/B and 2B-positive neurons was weakest in the molecular layer and stronger in the pyramidal layer, in particular the region with large cell bodies adjacent to the molecular layer. In the multiform layer, more positive neurons of various sizes were detected. CONCLUSION： NMDA 2A/B and 2B receptor subunits were richly distributed in the anterior thalamic nucleus, with a small difference existing between the anterior dorsal nucleus and anterior ventral nucleus. These neurons were also differentially distributed within the three layers of the subiculum complex.展开更多
The structures of limbic system have been found to modulate the auditory, visual and pain afferent signals in the related nuclei of thalamus. One of those structures is anterior cingulate cortex (ACC) that influences ...The structures of limbic system have been found to modulate the auditory, visual and pain afferent signals in the related nuclei of thalamus. One of those structures is anterior cingulate cortex (ACC) that influences nocuous response of the pain-sensitive neurons in the ventropos-tero-lateral nucleus of thalamus. Thus, we inferred that ACC would also modulate tactile information at the thalamic level. To test this assumption, single units were recorded extracellularly from thalamic ventrobasal nucleus (VB). Tactile ON-OFF response and the relationship between different patterns of the responses and the parameters of tactile stimulation were examined. Furthermore, the influence of ACC on the tactile ON-OFF response was studied. ACC stimulation was found to produce a facilitatory effect on the OFF-response of ON-OFF neurons. It lowered the threshold of the off-response of that neuron, and therefore changed the response pattern or enhanced the firing rate of the OFF-response of the neuron. The study on receptive fields of ON-OFF neurons showed that the excitation of the ACC could change an ON-response on the verge of a receptive field into an ON-OFF response. The above results suggest that the ACC modulation sharpens the response of a VB neuron to a moving stimulus within its receptive field, indicating that the limbic system can modulate tactile ascending sensory information.展开更多
基金the National Natural Science Foundation of China, No. 30470551a Category Project of the Education Department of Liaoning Province, No. 05L1021
文摘BACKGROUND：Glutamate acid ionotropic receptor N-methyl-D-aspartic acid （NMDA） takes part in long-term potentiation, thereby influencing the process of learning and memory. OBJECTIVE： To verify expression of NMDA 2A/B and 2B receptors in the anterior thalamic nucleus and subiculum complex of rats. DESIGN, TIME AND SETTING： A single-sample observation was performed at Department of Anatomy in Dalian Medical University （Dalian, Liaoning, China） from April to September in 2007. MATERIALS： Ten adult Wistar rats were used for this study, as well as rabbit anti-NMDA 2A/B and 2B antibodies. METHODS： The rats were anesthetized and perfused, followed by brain resection and coronal sectioning of the brain tissue. A 1：3 series was selected for immunohistochemistry, using antibodies specific to NMDA 2A/B and 2B receptors. Photos were taken using the Nikon image analysis system. MAIN OUTCOME MEASURES： Expression and distribution of immunohistochemistry staining of NMDA 2A/B and 2B receptor subunits. RESULTS： There were a large number of NMDA 2A/B and 2B receptor-positive neurons distributed throughout the anterior dorsal thalamic nucleus. In the anterior ventral thalamic nucleus, distribution of positive neurons was rare, staining intensity was lighter, and cell bodies were smaller compared with the anterior dorsal thalamic nucleus. In the subiculum complex, staining intensity of NMDA 2A/B and 2B-positive neurons was weakest in the molecular layer and stronger in the pyramidal layer, in particular the region with large cell bodies adjacent to the molecular layer. In the multiform layer, more positive neurons of various sizes were detected. CONCLUSION： NMDA 2A/B and 2B receptor subunits were richly distributed in the anterior thalamic nucleus, with a small difference existing between the anterior dorsal nucleus and anterior ventral nucleus. These neurons were also differentially distributed within the three layers of the subiculum complex.
文摘The structures of limbic system have been found to modulate the auditory, visual and pain afferent signals in the related nuclei of thalamus. One of those structures is anterior cingulate cortex (ACC) that influences nocuous response of the pain-sensitive neurons in the ventropos-tero-lateral nucleus of thalamus. Thus, we inferred that ACC would also modulate tactile information at the thalamic level. To test this assumption, single units were recorded extracellularly from thalamic ventrobasal nucleus (VB). Tactile ON-OFF response and the relationship between different patterns of the responses and the parameters of tactile stimulation were examined. Furthermore, the influence of ACC on the tactile ON-OFF response was studied. ACC stimulation was found to produce a facilitatory effect on the OFF-response of ON-OFF neurons. It lowered the threshold of the off-response of that neuron, and therefore changed the response pattern or enhanced the firing rate of the OFF-response of the neuron. The study on receptive fields of ON-OFF neurons showed that the excitation of the ACC could change an ON-response on the verge of a receptive field into an ON-OFF response. The above results suggest that the ACC modulation sharpens the response of a VB neuron to a moving stimulus within its receptive field, indicating that the limbic system can modulate tactile ascending sensory information.
