Objective To perform the modulation of an assay system for the sensory integration of 2 sensory stimuli that inhibit each other.Methods The assay system for assessing the integrative response to 2 reciprocally-inhibit...Objective To perform the modulation of an assay system for the sensory integration of 2 sensory stimuli that inhibit each other.Methods The assay system for assessing the integrative response to 2 reciprocally-inhibitory sensory stimuli was modulated by changing the metal ion barrier.Moreover,the hen-1,ttx-3 and casy-1 mutants having known defects in integrative response were used to evaluate the modulated assay systems.Based on the examined assay systems,new genes possibly involved in the sensory integration control were identified.Results In the presence of different metal ion barriers and diacetyl,locomotion behaviors,basic movements,pan-neuronal,cholinergic and GABAergic neuronal GFP expressions,neuronal development,structures of sensory neurons and interneurons,and stress response of nematodes in different regions of examined assay systems were normal,and chemotaxis toward different concentrations of diacetyl and avoidance of different concentrations of metal ions were inhibited.In the first group,most of the nematodes moved to diacetyl by crossing the barrier of Fe2＋,Zn2＋,or Mn2＋.In the second group,almost half of the nematodes moved to diacetyl by crossing the barrier of Ag＋,Cu2＋,Cr2＋,or Cd2＋.In the third group,only a small number of nematodes moved to diacetyl by crossing the barrier of Pb2＋ or Hg2＋.Moreover,when nematodes encountered different metal ion barriers during migration toward diacetyl,the percentage of nematodes moving back and then turning and that of nematodes moving straight to diacetyl were very different.With the aid of examined assay systems,it was found that mutations of fsn-1 that encodes a F-box protein,and its target scd-2 that encodes a receptor tyrosine kinase,caused severe defects in integrative response,and the sensory integration defects of fsn-1 mutants were obviously inhibited by scd-2 mutation.Conclusion Based on the nematode behaviors in examined assay systems,3 groups of assay systems were obtained.The first group may be helpful in evaluating or identifying the very subtle deficits in sensory integration,and the third group may be useful for the final confirmation of sensory integration defects of mutants identified in the first or the second group of assay systems.Furthermore,the important association of sensory integration regulation with stabilization or destabilization of synaptic differentiation may exist in C.elegans.展开更多
Objective The well-established planar multi-electrode array recording technique was used to investigate neural circuits and temporal plasticity in the hindlimb representation of the rat primary somatosensory cortex （...Objective The well-established planar multi-electrode array recording technique was used to investigate neural circuits and temporal plasticity in the hindlimb representation of the rat primary somatosensory cortex （S1 area） . Methods Freshly dissociated acute brain slices of rats were subject to constant perfusion with oxygenated artificial cerebrospinal fluid （95% O2 and 5% CO2） , and were mounted on a Med64 probe （64 electrodes, 8×8 array） for simultaneous multi-site electrophysiological recordings. Current sources and sinks across all the 64 electrodes were transformed into two-dimensional current source density images by bilinear interpolation at each point of the 64 electrodes. Results The local intracortical connection, which is involved in mediation of downward information flow across layers II-VI, was identified by electrical stimulation （ES） at layers II-III. The thalamocortical connection, which is mainly involved in mediation of upward information flow across layers II-IV, was also characterized by ES at layer IV. The thalamocortical afferent projections were likely to make more synaptic contacts with S1 neurons than the intracortical connections did. Moreover, the S1 area was shown to be more easily activated and more intensively innervated by the thalamocortical afferent projections than by the intracortical connections. Finally, bursting conditioning stimulus （CS） applied within layer IV of the S1 area could success-fully induce long-term potentiation （LTP） in 5 of the 6 slices （83.3%） , while the same CS application at layers II-III induced no LTP in any of the 6 tested slices. Conclusion The rat hindlimb representation of S1 area is likely to have at least 2 patterns of neural circuits on brain slices： one is the intracortical circuit （ICC） formed by interlaminar connections from layers II-III, and the other is the thalamocortical circuit （TCC） mediated by afferent connections from layer IV. Besides, ICC of the S1 area is spatially limited, with less plasticity, while TCC is spatially extensive and exhibits a better plasticity in response to somatosensory afferent stimulation. The present data provide a useful experimental model for further studying microcircuit properties in S1 cortex at the network level in vitro.展开更多
基金supported by the National Natural Science Foundation of China (No. 30870810)National Basic Research Program of China (No. 2011CB933404)
文摘Objective To perform the modulation of an assay system for the sensory integration of 2 sensory stimuli that inhibit each other.Methods The assay system for assessing the integrative response to 2 reciprocally-inhibitory sensory stimuli was modulated by changing the metal ion barrier.Moreover,the hen-1,ttx-3 and casy-1 mutants having known defects in integrative response were used to evaluate the modulated assay systems.Based on the examined assay systems,new genes possibly involved in the sensory integration control were identified.Results In the presence of different metal ion barriers and diacetyl,locomotion behaviors,basic movements,pan-neuronal,cholinergic and GABAergic neuronal GFP expressions,neuronal development,structures of sensory neurons and interneurons,and stress response of nematodes in different regions of examined assay systems were normal,and chemotaxis toward different concentrations of diacetyl and avoidance of different concentrations of metal ions were inhibited.In the first group,most of the nematodes moved to diacetyl by crossing the barrier of Fe2＋,Zn2＋,or Mn2＋.In the second group,almost half of the nematodes moved to diacetyl by crossing the barrier of Ag＋,Cu2＋,Cr2＋,or Cd2＋.In the third group,only a small number of nematodes moved to diacetyl by crossing the barrier of Pb2＋ or Hg2＋.Moreover,when nematodes encountered different metal ion barriers during migration toward diacetyl,the percentage of nematodes moving back and then turning and that of nematodes moving straight to diacetyl were very different.With the aid of examined assay systems,it was found that mutations of fsn-1 that encodes a F-box protein,and its target scd-2 that encodes a receptor tyrosine kinase,caused severe defects in integrative response,and the sensory integration defects of fsn-1 mutants were obviously inhibited by scd-2 mutation.Conclusion Based on the nematode behaviors in examined assay systems,3 groups of assay systems were obtained.The first group may be helpful in evaluating or identifying the very subtle deficits in sensory integration,and the third group may be useful for the final confirmation of sensory integration defects of mutants identified in the first or the second group of assay systems.Furthermore,the important association of sensory integration regulation with stabilization or destabilization of synaptic differentiation may exist in C.elegans.
基金supported by the National Basic Research Development Program(973)of China(No.2006CB500800)National Innovation Team Program of Ministry of Education(No.IRT0560)National Natural Science Foundation of China(No.30670692 and 30770668)
文摘Objective The well-established planar multi-electrode array recording technique was used to investigate neural circuits and temporal plasticity in the hindlimb representation of the rat primary somatosensory cortex （S1 area） . Methods Freshly dissociated acute brain slices of rats were subject to constant perfusion with oxygenated artificial cerebrospinal fluid （95% O2 and 5% CO2） , and were mounted on a Med64 probe （64 electrodes, 8×8 array） for simultaneous multi-site electrophysiological recordings. Current sources and sinks across all the 64 electrodes were transformed into two-dimensional current source density images by bilinear interpolation at each point of the 64 electrodes. Results The local intracortical connection, which is involved in mediation of downward information flow across layers II-VI, was identified by electrical stimulation （ES） at layers II-III. The thalamocortical connection, which is mainly involved in mediation of upward information flow across layers II-IV, was also characterized by ES at layer IV. The thalamocortical afferent projections were likely to make more synaptic contacts with S1 neurons than the intracortical connections did. Moreover, the S1 area was shown to be more easily activated and more intensively innervated by the thalamocortical afferent projections than by the intracortical connections. Finally, bursting conditioning stimulus （CS） applied within layer IV of the S1 area could success-fully induce long-term potentiation （LTP） in 5 of the 6 slices （83.3%） , while the same CS application at layers II-III induced no LTP in any of the 6 tested slices. Conclusion The rat hindlimb representation of S1 area is likely to have at least 2 patterns of neural circuits on brain slices： one is the intracortical circuit （ICC） formed by interlaminar connections from layers II-III, and the other is the thalamocortical circuit （TCC） mediated by afferent connections from layer IV. Besides, ICC of the S1 area is spatially limited, with less plasticity, while TCC is spatially extensive and exhibits a better plasticity in response to somatosensory afferent stimulation. The present data provide a useful experimental model for further studying microcircuit properties in S1 cortex at the network level in vitro.
