Meth- and other amphetamines currently present major drug-abuse concerns. However, the demonstration and study of abuse-related behaviors expressed in animal models is expensive and time-consuming. We previously repor...Meth- and other amphetamines currently present major drug-abuse concerns. However, the demonstration and study of abuse-related behaviors expressed in animal models is expensive and time-consuming. We previously reported a novel model of conditioned place preference (CPP), which is a standard tool in abuse research, in invertebrates (planarians). In the present study, planarians were tested for light/dark preference, then exposed for 5 min to either d-amphetamine or vehicle (water) in light and then re-tested for place preference (light vs dark). The planarians’ natural strong preference for dark (15 of 16) was significantly altered by amphetamine experience, such that 12 of 16 preferred the unnatural, but amphetamine-associated, light side. These results extend the demonstration of CPP to this invertebrate species and provide further evidence in support of this model to testing/screening amphetamine-like and possibly other drugs of abuse.展开更多
Purpose: To study the effect of time varying/ pulsing electromagnetic fields (PEMF) on bio-logical systems by measuring regrowth and the induction of elevated levels of the stress protein hsp70 in the regenerative mod...Purpose: To study the effect of time varying/ pulsing electromagnetic fields (PEMF) on bio-logical systems by measuring regrowth and the induction of elevated levels of the stress protein hsp70 in the regenerative model Planaria Duge-sia dorotocethala. Objective: The outcomes of studies using electromagnetic fields (EMF) are dependent on pulse design, field strength (mG), frequency (Hz), duration and magnetic field/rise time (dB/ dt). Standardization of effective pulse design is necessary to avoid continuing confu-sion in the investigation of pulsing electro-magnetic field (PEMF) technology. Information from studies on hsp70 protein induction and regrowth in transected Planaria provides in-formation on EMF efficacy for potential clinical application in the treatment of ischemia reper-fusion injury and the eventual inclusion of EMF prophylaxis prior to surgery. Materials and methods: Planaria were transected equidistant between the tip of the head and the tip of the tail. Individual head and tail portions from the same worm were placed in pond water and exposed to 8, 16 or 72 Hertz PEMF for one hour daily post transection under carefully controlled exposure conditions. Regrowth of heads and tails was measured in PEMF-exposed and sham control. Protein lysates from PEMF-exposed and sham control transected heads and tails were ana-lyzed for hsp70 levels by Wes￥tern blot analy-ses. Conclusion: The degree of regrowth and hsp70 levels in transected heads and tails ex-posed to nanosecond PEMF exposures at 8, 16 or 72 Hz was frequency dependent. There are currently several views on the interaction mechanism involved in regrowth. Here we dis-cuss two: in one [7,8] we propose a direct effect on the DNA of the PEMF consensus sequence, nCTCTn, referred to as electromagnetic field response elements (EMRE) in the promoter re-gion of the stress response gene HSP70. In the second mechanism [28] it is proposed that EMF induce vibrations of proteins through a series of quantized low frequency phonon signals.展开更多
Intermittent hypoxia or hypoxia therapy is exposing an individual to oxygenation conditions that are below atmospheric levels in a planned or acute timeframe. Hypoxia therapy is a potentially novel therapeutic strateg...Intermittent hypoxia or hypoxia therapy is exposing an individual to oxygenation conditions that are below atmospheric levels in a planned or acute timeframe. Hypoxia therapy is a potentially novel therapeutic strategy for a variety of pathologies including: mitochondrial disorders, exercise training, and mild cognitive impairments. Mitochondrial dysfunction, hyperkinetic movements, and cognitive impairments are hallmarks of seizures and status epilepticus (SE). A seizure can be considered uncontrolled electrical activity in the brain and SE is a seizure lasting more than 30 minutes, or multiple seizures without regaining consciousness in between. We examined the possibility of using the Pilocarpine model for seizure like activity on brown planaria (Dugesia tigrine). Pilocarpine is a muscarinic acetylcholine receptor agonist capable of creating seizure related brain damage. We utilized 5 mM dosages of pilocarpine and then measured open field behaviour for 3 minutes. Mobility and aversive hyperkinetic movements were observed throughout the measurement phase. After exposure to 5 mM pilocarpine, the planaria displayed behaviours consistent with seizures (e.g. aversive hyperkinetic movements and decreased mobility). Additionally, we measured the effects of an acute hypoxic event on Planaria behaviour. We used 25% carbonated water to create a hypoxic environment for the planaria and then measured mobility and hyperkinetic movements for 3 minutes. We noted that exposure to the hypoxic en-vironment produced no changes in behaviour. However, the aversive hyperkinetic move-ments produced with pilocarpine administration were completely absent when a brief (3 minutes) hypoxic episode followed the pilocarpine exposure (p < 0.05). Aversive behav-iours remained present when the ordering of pilocarpine and hypoxia were counterbal-anced. This ordering effect was consistent across 40 trials. Further evaluation of the pilo-carpine seizure model and intermittent hypoxia on planarian behaviour is warranted.展开更多
Background:The pluripotent stem cells in planarians,a model for tissue and cellular regeneration,remain further identification.We recently developed a method to enrich piwi-1+cells in Schmidtea mediterranea,by stainin...Background:The pluripotent stem cells in planarians,a model for tissue and cellular regeneration,remain further identification.We recently developed a method to enrich piwi-1+cells in Schmidtea mediterranea,by staining cells with SiR-DNA and Cell Tracker Green,named SirNeoblasts that permits their propagation and subsequent functional study in vivo.Since traditional enrichment for planarian neoblasts by Hoechst 33342 staining generates X1 cells,blocking the cell cycle and inducing cytotoxicity,this method by SiR-DNA and Cell Tracker Green represents a complementary technological advance for functional investigation of cell fate and regeneration.However,the similarities in heterogeneity of cell subtypes between SirNeoblasts and X1 remain unknown.Results:In this work,we performed single cell RNA sequencing of SirNeoblasts for comparison with differential expression patterns in a publicly available X1 single cell RNA sequencing data.We found first that all of the lineagespecific progenitor cells in X1 were present in comparable proportions in SirNeoblasts.In addition,SirNeoblasts contain an early muscle progenitor that is unreported in X1.Analysis of new markers for putative pluripotent stem cells identified here,with subsequent sub-clustering analysis,revealed earlier lineages of epidermal,muscular,intestinal,and pharyngeal progenitors than have been observed in X1.Using the gcm as a marker,we also identified a cell subpopulation resided in previously identified tgs-1+neoblasts.Knockdown of gcm impaired the neoblast repopulation,suggesting a function of gcm in neoblasts.Conclusions:In summary,the use of SirNeoblasts will enable broad experimental advances in regeneration and cell fate specification,given the possibility for propagation and transplantation of recombinant and mutagenized pluripotent stem cells that are not previously afforded to this rapid and versatile model system.展开更多
文摘Meth- and other amphetamines currently present major drug-abuse concerns. However, the demonstration and study of abuse-related behaviors expressed in animal models is expensive and time-consuming. We previously reported a novel model of conditioned place preference (CPP), which is a standard tool in abuse research, in invertebrates (planarians). In the present study, planarians were tested for light/dark preference, then exposed for 5 min to either d-amphetamine or vehicle (water) in light and then re-tested for place preference (light vs dark). The planarians’ natural strong preference for dark (15 of 16) was significantly altered by amphetamine experience, such that 12 of 16 preferred the unnatural, but amphetamine-associated, light side. These results extend the demonstration of CPP to this invertebrate species and provide further evidence in support of this model to testing/screening amphetamine-like and possibly other drugs of abuse.
文摘Purpose: To study the effect of time varying/ pulsing electromagnetic fields (PEMF) on bio-logical systems by measuring regrowth and the induction of elevated levels of the stress protein hsp70 in the regenerative model Planaria Duge-sia dorotocethala. Objective: The outcomes of studies using electromagnetic fields (EMF) are dependent on pulse design, field strength (mG), frequency (Hz), duration and magnetic field/rise time (dB/ dt). Standardization of effective pulse design is necessary to avoid continuing confu-sion in the investigation of pulsing electro-magnetic field (PEMF) technology. Information from studies on hsp70 protein induction and regrowth in transected Planaria provides in-formation on EMF efficacy for potential clinical application in the treatment of ischemia reper-fusion injury and the eventual inclusion of EMF prophylaxis prior to surgery. Materials and methods: Planaria were transected equidistant between the tip of the head and the tip of the tail. Individual head and tail portions from the same worm were placed in pond water and exposed to 8, 16 or 72 Hertz PEMF for one hour daily post transection under carefully controlled exposure conditions. Regrowth of heads and tails was measured in PEMF-exposed and sham control. Protein lysates from PEMF-exposed and sham control transected heads and tails were ana-lyzed for hsp70 levels by Wes￥tern blot analy-ses. Conclusion: The degree of regrowth and hsp70 levels in transected heads and tails ex-posed to nanosecond PEMF exposures at 8, 16 or 72 Hz was frequency dependent. There are currently several views on the interaction mechanism involved in regrowth. Here we dis-cuss two: in one [7,8] we propose a direct effect on the DNA of the PEMF consensus sequence, nCTCTn, referred to as electromagnetic field response elements (EMRE) in the promoter re-gion of the stress response gene HSP70. In the second mechanism [28] it is proposed that EMF induce vibrations of proteins through a series of quantized low frequency phonon signals.
文摘Intermittent hypoxia or hypoxia therapy is exposing an individual to oxygenation conditions that are below atmospheric levels in a planned or acute timeframe. Hypoxia therapy is a potentially novel therapeutic strategy for a variety of pathologies including: mitochondrial disorders, exercise training, and mild cognitive impairments. Mitochondrial dysfunction, hyperkinetic movements, and cognitive impairments are hallmarks of seizures and status epilepticus (SE). A seizure can be considered uncontrolled electrical activity in the brain and SE is a seizure lasting more than 30 minutes, or multiple seizures without regaining consciousness in between. We examined the possibility of using the Pilocarpine model for seizure like activity on brown planaria (Dugesia tigrine). Pilocarpine is a muscarinic acetylcholine receptor agonist capable of creating seizure related brain damage. We utilized 5 mM dosages of pilocarpine and then measured open field behaviour for 3 minutes. Mobility and aversive hyperkinetic movements were observed throughout the measurement phase. After exposure to 5 mM pilocarpine, the planaria displayed behaviours consistent with seizures (e.g. aversive hyperkinetic movements and decreased mobility). Additionally, we measured the effects of an acute hypoxic event on Planaria behaviour. We used 25% carbonated water to create a hypoxic environment for the planaria and then measured mobility and hyperkinetic movements for 3 minutes. We noted that exposure to the hypoxic en-vironment produced no changes in behaviour. However, the aversive hyperkinetic move-ments produced with pilocarpine administration were completely absent when a brief (3 minutes) hypoxic episode followed the pilocarpine exposure (p < 0.05). Aversive behav-iours remained present when the ordering of pilocarpine and hypoxia were counterbal-anced. This ordering effect was consistent across 40 trials. Further evaluation of the pilo-carpine seizure model and intermittent hypoxia on planarian behaviour is warranted.
基金K.L.is supported by the National Natural Science Foundation of China(31970750)the start-up fund from the Westlake Education Foundation.
文摘Background:The pluripotent stem cells in planarians,a model for tissue and cellular regeneration,remain further identification.We recently developed a method to enrich piwi-1+cells in Schmidtea mediterranea,by staining cells with SiR-DNA and Cell Tracker Green,named SirNeoblasts that permits their propagation and subsequent functional study in vivo.Since traditional enrichment for planarian neoblasts by Hoechst 33342 staining generates X1 cells,blocking the cell cycle and inducing cytotoxicity,this method by SiR-DNA and Cell Tracker Green represents a complementary technological advance for functional investigation of cell fate and regeneration.However,the similarities in heterogeneity of cell subtypes between SirNeoblasts and X1 remain unknown.Results:In this work,we performed single cell RNA sequencing of SirNeoblasts for comparison with differential expression patterns in a publicly available X1 single cell RNA sequencing data.We found first that all of the lineagespecific progenitor cells in X1 were present in comparable proportions in SirNeoblasts.In addition,SirNeoblasts contain an early muscle progenitor that is unreported in X1.Analysis of new markers for putative pluripotent stem cells identified here,with subsequent sub-clustering analysis,revealed earlier lineages of epidermal,muscular,intestinal,and pharyngeal progenitors than have been observed in X1.Using the gcm as a marker,we also identified a cell subpopulation resided in previously identified tgs-1+neoblasts.Knockdown of gcm impaired the neoblast repopulation,suggesting a function of gcm in neoblasts.Conclusions:In summary,the use of SirNeoblasts will enable broad experimental advances in regeneration and cell fate specification,given the possibility for propagation and transplantation of recombinant and mutagenized pluripotent stem cells that are not previously afforded to this rapid and versatile model system.
