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Sean Nash

Learning in Plants: Lessons from Mimosa pudica - 4 views

www.frontiersin.org/...full

Mimosa learning plants botany research SCI-I science student lab potential research idea biology HSR HSR-2023

shared by Sean Nash on 23 Jun 23 - No Cached
  • there is a lack of observational data on the behavior of plants
  • Observational research allows the researcher to establish baseline activity and response levels of the subject
  • Perhaps the first study of learning in plants was a habituation experiment reported by Pfeffer (1873) using the sensitive plant Mimosa. In this experiment, repeated mechanical stimulation of leaflets led to a decrease in sensitivity
  • ...12 more annotations...
  • the question naturally arises as to whether Mimosa can discriminate between stimuli. This was answered in the affirmative by Holmes and Gruenberg (1965) whose experimental design included a drop of water and finger touch as stimuli
  • the results suggest that Mimosa can discriminate between stimuli
  • Thomas performed an experiment on classical conditioning in Mimosa that took advantage of the finding that, under field conditions, the leaflets of Mimosa slowly drop as dusk approaches and slowly rise at dawn (personal communication). In the experiment, the CS was turning on the light in the growth chamber and the US was touching selected leaflets. Thomas found that leaflets in the paired condition showed conditioning compared to a light only or alternating stimulation condition. This finding should be replicated with controls for pseudoconditioning.
  • Given the importance of the Gagliano et al. (2014) experiment and the failure to replicate some previous experimental results it is critical that the Gagliano et al. (2014) results be repeated by an independent laboratory.
  • In addition to Mimosa, habituation has been found in the carnivorous plant Drosera (sundew
  • Applewhite (1975) cites an experiment by Darwin reportedly showing habituation in the passion flower (Passiflora gracilis). During this experiment, when Darwin mechanically stimulated the passion flower tendrils, the tendrils no longer responded after 54 h of training.
  • Abramson et al. (2002) investigated the use of bioelectrical potentials as a method to explore plant behavior.
  • In an interesting article, Karpinski and Szechynska-Hebda (2010) discuss the intellect of plants from memory to intelligence. By studying recall, the researcher investigates a host of independent variables and that are solidly anchored to a set of dependent variables. This study focused on recall at the cellular level rather than as an externally observable behavior. The discussion of plant learning at various levels, from cellular to organismal and from different scientific fields is exactly what is advocated for in this article
  • There is also interest from behavioral scientists seeking to determine whether the similarities and differences in learning found among invertebrates and vertebrates could also be found in plants (Warden et al., 1940; Applewhite, 1975; Abramson et al., 2002; Guiguet, 2013).
  • The majority of early plant studies used the Sensitive plant (M. pudica). Mimosa has much to recommend it for learning studies. They are easy to maintain, much is known about its natural history, and they have a visible leaf closure response to external stimuli. However, there are drawbacks in the use of Mimosa, for example, it takes about 15 min for a leaf to recover (Holmes and Gruenberg, 1965) and not much is known about its genome in contrast to model species such as Arabidopsis thaliana whose entire genome is known.
  • In the following section we will focus on methods to develop studies utilizing habituation, sensitization, and classical conditioning techniques. Instrumental and operant conditioning will not be covered because at this time there are no Mimosa studies in these areas; although one can envision a situation where the opening and closing of a leaf can be detected electronically. Once detected, the response would produce a consequence such as an airpuff or changes in light intensity.
    • Sean Nash
      Sean Nash on 23 Jun 23
       
      The remainder of this comprehensive article is to outline the main lines of research in this area:
  • Learning in Plants: Lessons from Mimosa pudica
    • Sean Nash
      Sean Nash on 23 Jun 23
       
      This well-compiled article does a really nice job of outlining the history of study regarding plant behavior. It also suggests model organisms for study. Mimosa is a favorite of mine as their response is VERY rapid and quite visible for a plant! There are all sorts of feasible project ideas that could arise from this area of research.
katherine-medina

Effects of experimental increase in insulin-like growth factor 1 on feather growth rate... - 0 views

journals.biologists.com/...ental-increase-in-insulin-like

birds biology HSR2023 insulin plumage feathers molt

shared by katherine-medina on 10 Jul 23 - No Cached
  • In mammals, IGF-1 also induces the proliferation of hair follicles and inhibits apoptosis, and therefore helps to keep them longer in the active (so-called anagen) phase and delay their transition to the regressive (catagen) phase
  • while a recently published study indicated a positive relationship between plumage quality, feather vane length and IGF-1 in a passerine species
  • Detailed quantification of the moulting stage was achieved by scoring the moult of the primary wing feathers and tail feathers on a scale of 0–5, using the standard protocol for recording the progress of feather growth as suggested by the British Trust for Ornithology and further described in
    • katherine-medina
      katherine-medina on 10 Jul 23
       
      I had no idea one could predict when a bird will molt.
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  • As a result, 2 weeks after treatment, IGF-1-treated birds were in a more advanced stage of moult than controls
    • katherine-medina
      katherine-medina on 10 Jul 23
       
      Interesting
  • In the longer term, IGF-1 treatment altered the intensity of moult: 2 weeks after treatment, control birds were moulting fewer feathers than at the start of the experiment, while IGF-1-treated birds showed the opposite pattern and increased the number of feathers being moulted simultaneously, albeit with substantial individual variation
  • We manipulated IGF-1 levels using an injection of poly-(lactic-co-glycolid acid) (PLGA) microspheres prepared by S.V.-K. and B.A.G. as described previousl
  • For example, stressors may cause a decrease in circulating IGF-1 levels (Tóth et al., 2018), and it may not be beneficial if that would affect the growth rate or the size of the developing flight feathers.
  • The fact that the growth of the tail feathers was also unaffected by the manipulation is more surprising as they are sexually selected ornaments in this species
    • katherine-medina
      katherine-medina on 10 Jul 23
       
      Wow, I wonder why it had no effect on the growth of the tail feathers.
  • espite the robust lack of effect on feather growth speed, IGF-1 treatment maintained or even increased the number of feathers moulted simultaneously within 2 weeks, while the number of simultaneously growing feathers dropped in controls within the same period
    • katherine-medina
      katherine-medina on 10 Jul 23
       
      Cool
  • In contrast to hair, the number of feather follicles that produce wing and tail feathers is small and shows no variation within species
    • katherine-medina
      katherine-medina on 10 Jul 23
       
      I had no idea.
  • Some species, however, moult several wing and tail feathers simultaneously, which also applies to the bearded reedling
    • katherine-medina
      katherine-medina on 10 Jul 23
       
      Why do some species of birds molt more feathers at the same time than others.
  • . Protein synthesis in tissues, for example, is partly promoted by and regulated through IGF-1 and this might also be of importance during the growth of feathers, in particular considering the increased demand for proteins during moulting
  • The interaction of corticosterone and IGF-1 has been suggested to predict fitness in growing songbirds (Lodjak et al., 2016). Corticosterone levels are known to have a seriously detrimental effect on growing feathers
    • katherine-medina
      katherine-medina on 10 Jul 23
       
      How does corticosterone and IGF-1 interact?
  • katherine-medina on 10 Jul 23
     
    A study about the effect of insulin on the growth of feathers.
Hannah Herrera

Space travel alters gene expression in white blood cells, weakening our immune system -... - 1 views

blog.frontiersin.org/...on-leukocytes-changes-in-space

questions space physics gene alterations astronauts

shared by Hannah Herrera on 24 Jun 23 - No Cached
  • Space travel alters gene expression in white blood cells, weakening our immune system
    • Hannah Herrera
      Hannah Herrera on 24 Jun 23
       
      very interesting article, there is a conclusion with insights to this underlining issue in the "read original paper" link in red. I overall think its a ear pricking issue that has yet to be solve or given the clear conclusion as to why it happens in the first place.
  • pre-flight strength: the length of this period is likely to depend on age, sex, genetic differences, and childhood exposure to pathogens.
  • These observations suggest that our immune system might be weakened by space travel.
    • Hannah Herrera
      Hannah Herrera on 24 Jun 23
       
      could it have a possible connection with the strong gravitational pull while actually going up to space? (like the continuing feeling of a steep rollercoaster drop).
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  • change in gene expression of leukocytes under microgravity is triggered by ‘fluid shift’, where blood plasma is redistributed from the lower to the upper part of the body, including the lymphatic system. This causes a reduction in plasma volume by between 10% and 15% within the first few days in space. Fluid shift is known to be accompanied by large-scale physiological adaptations, apparently including altered gene expression.
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