ArticlePDF Available

Fungi anaesthesia

Authors:

Abstract and Figures

Electrical activity of fungus Pleurotus ostreatus is characterised by slow (h) irregular waves of baseline potential drift and fast (min) action potential likes spikes of the electrical potential. An exposure of the myceliated substrate to a chloroform vapour lead to several fold decrease of the baseline potential waves and increase of their duration. The chloroform vapour also causes either complete cessation of spiking activity or substantial reduction of the spiking frequency. Removal of the chloroform vapour from the growth containers leads to a gradual restoration of the mycelium electrical activity.
This content is subject to copyright. Terms and conditions apply.
1
Vol.:(0123456789)
Scientic Reports | (2022) 12:340 | https://doi.org/10.1038/s41598-021-04172-0
www.nature.com/scientificreports
Fungi anaesthesia
Andrew Adamatzky1* & Antoni Gandia2
Electrical activity of fungus Pleurotus ostreatus is characterised by slow (h) irregular waves of baseline
potential drift and fast (min) action potential likes spikes of the electrical potential. An exposure of the
myceliated substrate to a chloroform vapour lead to several fold decrease of the baseline potential
waves and increase of their duration. The chloroform vapour also causes either complete cessation of
spiking activity or substantial reduction of the spiking frequency. Removal of the chloroform vapour
from the growth containers leads to a gradual restoration of the mycelium electrical activity.
Most living cells are sensitive to anaesthetics13. First experiments on anaesthesia of plants have be done by
Claude Bernard in late 1800s4. Later experiments on amoeba5 shown that weak concentration of narcotics causes
the amoebae to spread out and propagate in a spread condition while narcotic concentrations led to cessation
of movements. During last century the experimental evidences mounted up including anaesthesia of yeasts1,
various aquatic invertebrates6, plants3,7, protists8, bronchial ciliated cells9. A general consensus now is that any
living substrate can be anaesthetised3. e question remains, however, how exactly species without a nervous
system would respond to exposure to anaesthetics.
In present paper we focus on fungi anaesthesia. Why fungi? Fungi are the largest, most widely distributed, and
oldest group of living organisms10. Smallest fungi are microscopic single cells. e largest (15 hectares) mycelium
belongs to Armillaria gallica (synonymous with A. bulbosa, A. inata, and A. lutea)11 and the largest fruit body
belongs to Phellinus ellipsoideus (formerly Fomitiporia ellipsoidea) which weighs half-a-ton12.
Fungi exhibit a high degree of protocognitive abilities. For example, they are capable for ecient exploration
of conned spaces1317. Moreover, optimisation of the mycelial network18 is similar to that of the slime mould
Physarum polycephalum19 and transport networks20. erefore, we can speculate that the fungi can solve the
same range of computational problems as P. polycephalum21, including shortest path2226, Voronoi diagram27,
Delaunay triangulation, proximity graphs and spanning tree, concave hull and, possibly, convex hull, and, with
some experimental eorts, travelling salesman problem28. e fungi’s protocognitive abilities and computational
potential make them fruitful substrates for anaesthesia because they might show us how non-neuron awareness
is changing under eects of narcotics.
We use extracellular electrical potential of mycelium as indicator of the fungi activity. Action potential-like
spikes of electrical potential have been discovered using intra-cellular recording of mycelium of Neurospora
crassa29 and further conrmed in intra-cellular recordings of action potential in hyphae of Pleurotus ostreatus
and A. gallica30 and in extra-cellular recordings of fruit bodies of and substrates colonised by mycelium of P.
ostreatus31. While the exact nature of the travelling spikes remains uncertain we can speculate, by drawing analo-
gies with oscillations of electrical potential of slime mouldPhysarum polycephalum3235, that the spikes in fungi
are triggered by calcium waves, reversing of cytoplasmic ow, translocation of nutrients and metabolites. Stud-
ies of electrical activity of higher plants can brings us even more clues. us, the plants use the electrical spikes
for a long-distance communication aimed to coordinate the activity of their bodies3638. e spikes of electrical
potential in plants relate to a motor activity3942, responses to changes in temperature43, osmotic environment44,
and mechanical stimulation45,46.
e paper is structured as follows. We present the experimental setup in “Methods” section. Analysis of the
electrical activity of the intact non-anesthetised and anaesthetised fungi is given in “Results” section. “Discus-
sion” section present some critique and directions for further research.
Methods
A commercial strain of the fungus Pleurotus ostreatus (collection code 21-18, Mogu S.r.l., Italy), previously
selected for its superior tness growing on the targeted substrate, was cultured on sterilised hemp shives con-
tained in plastic (PP5) lter patch microboxes (SacO2, Belgium) that were kept in darkness at ambient room
temperature c.22
C. Aer one week of incubation, a hemp brick well colonised by the fungus was manually
crumbled and spread on rectangular fragments, c.
12
×
12 cm2
, of moisturised non-woven hemp pads. When
these fragments were colonised, as visualised by white and healthy mycelial growth on surface, they were used
for experiments.
OPEN
1Unconventional Computing Laboratory, UWE, Bristol, UK. 2Institute for Plant Molecular and Cell Biology,
CSIC-UPV, Valencia, Spain. *email: andrew.adamatzky@uwe.ac.uk
Content courtesy of Springer Nature, terms of use apply. Rights reserved
2
Vol:.(1234567890)
Scientic Reports | (2022) 12:340 | https://doi.org/10.1038/s41598-021-04172-0
www.nature.com/scientificreports/
Electrical activity of the colonised hemp pads was recorded using pairs of iridium-coated stainless steel
sub-dermal needle electrodes (Spes Medica S.r.l., Italy), with twisted cables and ADC-24 (Pico Technology,
UK) high-resolution data logger with a 24-bit A/D converter. To keep electrodes stable we have been placing
a polyurethane pad under the fabric. e electrodes were arranged in a line (Fig.1a,b). e pairs of electrodes
were pierced through the fabric and into the polyurethane pad.
e fungal substrates pierced with electrodes was placed into 20cm by 10cm by 10cm plastic boxes with
tight lids.
We recorded electrical activity at one sample per second. During the recording, the logger has been doing
as many measurements as possible (typically up to 600 per second) and saving the average value. We set the
acquisition voltage range to 156mV with an oset accuracy of 9
µ
V at 1Hz to maintain a gain error of 0.1%.
Each electrode pair was considered independent with the noise-free resolution of 17 bits and conversion time
of 60ms. Each pair of electrodes, called channels, reported a dierence of the electrical potential between the
electrodes. Distance between electrodes was 1-2cm. In each trial, we recorded eight electrode pairs, channels,
simultaneously.
To study the eect of chloroform we soaked a piece of lter paper c. 4cm by 4cm in chloroform (Sigma
Aldrich, analytical standard) and placed the piece of paper inside the plastic container with the recorded fungal
substrate.
e humidity of the fungal colonies was 70–80% (MerlinLaser Protimeter, UK). e experiments were con-
ducted in a room with ambient temperature 21
C and in the darkness of protective growing tents (Fig.1c).
We have conducted ten experiments, in each experiments we recorded electrical activity of the fungi via eight
channels, i.e. 80 recordings in total.
Figure1. Experimental setup. (a, b)Exemplar locations of electrodes. (a)Top view. (b)Side view. (c)Setup in
the grow tent.
Content courtesy of Springer Nature, terms of use apply. Rights reserved
3
Vol.:(0123456789)
Scientic Reports | (2022) 12:340 | https://doi.org/10.1038/s41598-021-04172-0
www.nature.com/scientificreports/
Results
Myceliated hemp pad exhibit patterns of electrical activity similar to that of spiking neural tissue. Examples of
action potential like spikes, solitary and in trains, are shown in Fig.2.
Application of the chloroform to the container with fungi substantially aected the electrical activity of the
fungi. An example of an extreme, i.e. where almost all electrical activity of mycelium seized, response is shown
in Fig.3. In this example, the introduction of the chloroform leads to the suppression of the spiking activity and
reduction of deviation in values of the electrical potential dierences recorded on the channels.
e intact, non-anesthetised, mycelium composite (control ) shows median amplitude of the irregular move-
ments of the baseline potential is 0.45mV (average 0.64mV,
σ=0.64
), median duration 29,850s (average
67,507s,
σ
=
29,850
). Aer exposure to chloroform the baseline potential movements show median amplitude
reduced to 0.16mV (average 0.18mV,
σ=0.12
) and median duration increased to 38,507s (average 38,114s,
σ
=
38,507
). For the eight channels (pairs of dierential electrodes) recorded exposure to chloroform led to
nearly three times decrease in amplitude of the dris of baseline potential and nearly 1.3 increase in duration
of the dris. Before exposure to chloroform the mycelium composite produced fast (i.e. less than 10–20min)
spikes. Median amplitude of the spikes was 0.48mV (average 0.52mV,
). Median duration of spikes was
62s (average 63s,
σ=18
), median distance between the spike 214s (average 189s,
σ=90
). Aer exposure to
Figure2. Example of spiking activity recorded from a control sample; an intact, non-anesthetised, myceliated
hemp pad. Spikes are shown by arrows.
Figure3. An example showing how the electrical activity of fungi changes when chloroform is introduced. e
moment of the chloroform introduction is shown by arrow.
Content courtesy of Springer Nature, terms of use apply. Rights reserved
4
Vol:.(1234567890)
Scientic Reports | (2022) 12:340 | https://doi.org/10.1038/s41598-021-04172-0
www.nature.com/scientificreports/
chloroform the mycelium composite did not show any spiking activity above level of background noise, which
was for this particular recording c. 0.05mV.
In some cases the spiking activity is diminished gradually with decreased frequency and lowered amplitude,
as exemplied in Fig.4. Typically, the intact (control) spiking frequency is a spike per 70min while aer inhala-
tion of chloroform a spike per 254min in the rst 40-50hours and decreased to nearly zero aer. e median
amplitude of intact mycelium spikes is 0.51mV, average 0.74mV (
σ
=0.59). Anaesthetised mycelium shows,
spikes with median amplitude 0.11mV, average 0.2mV (
). Spikes are not distributed uniformly but
gathered in trains of spikes. In the intact mycelium there is a media of 3 spikes in the train, average number of
spikes is 4.2 (
σ=4.4
). Median duration of a spike train is 84min, average 112min (
σ=32
). Media interval
between trains is 53min, average 55s (
σ=29
). Anaesthetised mycelium emits trains with median number of
2 spikes, average 2.5 spikes, average 2.5 spikes (
σ=0.84
). A median duration of such trains is 29min, average
51min (
σ=22
). e trains appear much more rarely than the trains in the intact mycelium: median interval
between trains is 227min.
In all ten but one experiment the container remained closed for over 3–4days. By that time all kinds of
electrical activity in mycelium bound substrate extinguished and the mycelium never recovered to a functional
state. In experiment illustrated in Fig.5 we removed a source of chloroform aer 16h and kept the container
open and well ventilated for an hour to remove any traces of chloroform from the air. e intact mycelium shows
median frequency of spiking as one spike per 27min, average 24min. Median amplitude of the spikes is 3.4mV,
average 3.25mV (
σ=1.45
). e anaesthetised mycelium demonstrates electrical spiking activity reduced in
amplitude: median amplitude of spikes is 0.24mV, average 0.32mV (
σ=0.2
), and low frequency of spiking:
median distance between spikes is 38min, average 40min. Electrical activity of the mycelium restores to above
noise level c.60h aer the source of the chloroform is removed from the enclosure (insert in Fig.5). Frequency
of spikes is one spike per 82min (median), average 88min. e amplitudes of recovering spikes are 0.96mV
in median (average 0.93mV,
σ=0.08
) which are three times less than of the spikes in the mycelium before the
narcosis but nearly ve times higher than of the spike of the anaesthetised mycelium.
Discussion
We demonstrated that the electrical activity of the fungus Pleurotus ostreatus is a reliable indicator of the fungi
anaesthesia. When exposed to a chloroform vapour the mycelium reduces frequency and amplitude of its spik-
ing and, in most cases, cease to produce any electrical activity exceeding the noise level (Table1a). When the
chloroform vapour is eliminated from the mycelium enclosure the mycelium electrical activity restores to a level
similar to that before anaesthesia (Table1b).
e fungal responses to chloroform are similar to that recorded by us with slime mould Physarum polycepha-
lum (unpublished results). A small concentration of anaesthetic leads to reduced frequency and amplitude of
electrical potential oscillation spikes of the slime mould, and some irregularity of the electrical potential spikes
(Fig.6a). Large amounts of anaesthetic causes the electrical activity to cease completely and never recover
(Fig.6b). Similar electrical responses to anaesthetic again highlights the fact that slime mould exhibits same-
degree anities with fungi as with protozoa, and slime mould has been classied as fungi previously4749.
Potential, mV
1.0
0.5
0
0.5
1.0
1.5
Time, sec
011052 1053 1054 105
Figure4. Example of reduced frequency of spiking under eect of chloroform vapour. Moment when a source
of chloroform vapour was added into the container is shown by arrow.
Content courtesy of Springer Nature, terms of use apply. Rights reserved
5
Vol.:(0123456789)
Scientic Reports | (2022) 12:340 | https://doi.org/10.1038/s41598-021-04172-0
www.nature.com/scientificreports/
Results presented in the paper contribute towards lling up the gaps in the taxonomy-related studies of
anaesthesia, the living creatures from Protists to fungi to plants to insects to mammals are susceptible to anaes-
thetics. Eects of chloroform on fungi might also implicitly indicate presence of potassium channels, which are
inhibited by anaesthetics5052.
With regards to directions of future research, as far as we are aware, the present paper is the rst in the eld,
and therefore it rather initiates the research than brings any closure or conclusions. We know that anaesthetics
block electrical activity of fungi (as well as slime moulds) however we do not know exact biophysical mechanisms
of these actions. e study of biophysics and molecular biology of fungi anaesthesia could be a scope for future
research. Another direction of studies could be the analysis of the decision making abilities of fungi under the
inuence of anaesthetics. An experiment could be constructed when fungal hyphae are searching for an optimal
path in a labyrinth when subjected to increasing doses of chloroform vapour. ere may be an opportunity to
make a mapping from concentrations of anaesthetic to geometry of the mycelium search path.
Figure5. Example of electrical activity of mycelium colonised hemp pad before, during and aer stimulation
with chloroform vapour. Arrow labelled ‘ON’ shows moment when a source of chloroform vapour was added
into the enclosure, ‘OFF’ when the source of chloroform was removed. e spiking activity of the mycelium
recovering from anaesthesia is zoomed in.
Table 1. Anaesthesia induced changes in electrical activity of fungi. (a)Containers with chloroform remain
sealed. (b)Lid from the container is removed aer 16h.
a b
Intact Anaesthetised Intact Anaesthetised Recovered
Baseline potential 0.64mV 0.18mV Spike amplitude 3.25mV 0.32 mV 0.93mV
Duration of oscillations
29 ·103
28 ·103
Spike frequency 24min 40min 88min
Spike amplitude 0.4mV 0
Spike duration 62s n/a
Spike frequency 214s n/a
Content courtesy of Springer Nature, terms of use apply. Rights reserved
6
Vol:.(1234567890)
Scientic Reports | (2022) 12:340 | https://doi.org/10.1038/s41598-021-04172-0
www.nature.com/scientificreports/
Received: 19 June 2021; Accepted: 13 December 2021
References
1. Sonner, J. M. A hypothesis on the origin and evolution of the response to inhaled anesthetics. Anesth . Analg. 107, 849 (2008).
2. Eckenho, R. G. Why can all of biology be anesthetized?. Anesth. Analg. 107, 859–861 (2008).
3. Grémiaux, A., Yokawa, K., Mancuso, S. & Baluška, F. Plant anesthesia supports similarities between animals and plants: Claude
Bernard’s forgotten studies. Plant Signal. Behav. 9, e27886 (2014).
4. Bernard, C. etal. Lectures on the Phenomena of Life Common to Animals And Plants. Translation by Hebbel E. Ho, Roger Guil-
lemin [and] Lucienne Guillemin (1974).
5. Hiller, S. Action of narcotics on the ameba by means of microinjection and immersion. Proc. Soc. Exp. Biol. Med. 24, 427–428
(1927).
6. Oliver, A., Deamer, D. & Akeson, M. Sensitivity to anesthesia by pregnanolone appears late in evolution. Ann. N. Y. Acad. Sci. 625,
561–565 (1991).
Figure6. Response of slime mould Physarum polycephalum to triuoroethane (Sigma Aldrich, UK). Electrical
potential dierence between two sites of 10mm long protoplasmic tube was measured using aluminium
electrodes, amplied and digitised with ADC-20 (Pico Technology, UK). (a)5
µ
L of triuoroethane applied to a
5mm
×
5mm piece of lter paper placed in the Petri dish with slime mould. (b)25
µ
L applied. Arrows indicate
moments when the piece of paper soaked in triuoroethane was placed in a Petri dish with the slime mould.
Content courtesy of Springer Nature, terms of use apply. Rights reserved
7
Vol.:(0123456789)
Scientic Reports | (2022) 12:340 | https://doi.org/10.1038/s41598-021-04172-0
www.nature.com/scientificreports/
7. Milne, A. & Beamish, T. Inhalational and local anesthetics reduce tactile and thermal responses in Mimosa pudica. Can. J. Anesth.
46, 287–289 (1999).
8. Nunn, J., Sturrock, J. E., Wills, E., Richmond, J. E. & McPherson, C. e eect of inhalational anaesthetics on the swimming velocity
of Tetrahymena pyriformis. J. Cell Sci. 15, 537–554 (1974).
9. Verra, F. et al. Eects of local anaesthetics (lidocaine) on the structure and function of ciliated respiratory epithelial cells. Biol. Cell
69, 99–105 (1990).
10. Carlile, M. J., Watkinson, S. C. & Gooday, G. W. e Fungi (Gulf Professional Publishing, 2001).
11. Smith, M. L., Bruhn, J. N. & Anderson, J. B. e fungus Ar millaria bulbosa is among the largest and oldest living organisms. Nature
356, 428 (1992).
12. Dai, Y.-C. & Cui, B.-K. Fomitiporia ellipsoidea has the largest fruiting body among the fungi. Fungal Biol. 115, 813–814 (2011).
13. Hanson, K. L. et al. Fungi use ecient algorithms for the exploration of microuidic networks. Small 2, 1212–1220 (2006).
14. Held, M., Edwards, C. & Nicolau, D.V. Examining the behaviour of fungal cells in microconned mazelike structures. In Imaging,
Manipulation, and Analysis of Biomolecules, Cells, and Tissues VI, vol. 6859, 68590U (International Society for Optics and Photon-
ics, 2008).
15. Held, M., Edwards, C. & Nicolau, D. V. Fungal intelligence; or on the behaviour of microorganisms in conned micro-environ-
ments. J. Phys. Conf. Ser. 178, 012005 (2009).
16. Held, M., Lee, A. P., Edwards, C. & Nicolau, D. V. Microuidics structures for probing the dynamic behaviour of lamentous fungi.
Microelectron. Eng. 87, 786–789 (2010).
17. Held, M., Edwards, C. & Nicolau, D. V. Probing the growth dynamics of Neurospora crassa with microuidic structures. Fungal
Biol. 115, 493–505 (2011).
18. Boddy, L., Hynes, J., Bebber, D. P. & Fricker, M. D. Saprotrophic cord systems: dispersal mechanisms in space and time. Mycosci-
ence 50, 9–19 (2009).
19. Adamatzky, A. Developing proximity graphs by Physarum polycephalum: Does the plasmodium follow the toussaint hierarchy?.
Parallel Process. Lett. 19, 105–127 (2009).
20. Adamatzky, A. (ed.) Bioevaluation of World Transport Networks (World Scientic, 2012).
21. Adamatzky, A. (ed.) Advances in Physarum Machines: Sensing and Computing with Slime Mould (Springer, 2016).
22. Nakagaki, T., Yamada, H. & Tóth, Á. Intelligence: Maze-solving by an amoeboid organism. Nature 407, 470 (2000).
23. Nakagaki, T. Smart behavior of true slime mold in a labyrinth. Res. Microbiol. 152, 767–770 (2001).
24. Nakagaki, T., Yamada, H. & Toth, A. Path nding by tube morphogenesis in an amoeboid organism. Biophys. Chem. 92, 47–52
(2001).
25. Nakagaki, T. et al. Minimum-risk path nding by an adaptive amoebal network. Phys. Rev. Lett. 99, 068104 (2007).
26. Tero, A. et al. Rules for biologically inspired adaptive network design. Science 327, 439–442 (2010).
27. Shirakawa, T., Adamatzky, A., Gunji, Y.-P. & Miyake, Y. On simultaneous construction of Voronoi diagram and delaunay triangula-
tion by Physarum polycephalum. Int. J. Bifurc. Chaos 19, 3109–3117 (2009).
28. Jones, J. & Adamatzky, A. Computation of the travelling salesman problem by a shrinking blob. Nat. Comput. 13, 1–16 (2014).
29. Slayman, C. L., Long, W. S. & Gradmann, D. “Action potentials’’ in Neurospora crassa, a mycelial fungus. Biochim. Biophys. Acta
Biomembr. 426, 732–744 (1976).
30. Olsson, S. & Hansson, B. Action potential-like activity found in fungal mycelia is sensitive to stimulation. Naturwissenschaen 82,
30–31 (1995).
31. Adamatzky, A. On spiking behaviour of oyster fungi Pleurotus djamor. Sci. Rep. 8, 1–7 (2018).
32. Iwamura, T. Correlations between protoplasmic streaming and bioelectric potential of a slime mold, Physarum polycephalum.
Shokubutsugaku Zasshi 62, 126–131 (1949).
33. Kamiya, N. & Abe, S. Bioelectric phenomena in the myxomycete plasmodium and their relation to protoplasmic ow. J. Colloid
Sci. 5, 149–163 (1950).
34. Kishimoto, U. Rhythmicity in the protoplasmic streaming of a slime mold, Physarum polycephalum. I. A statistical analysis of the
electric potential rhythm. J. Gen. Physiol. 41, 1205–1222 (1958).
35. Meyer, R. & Stockem, W. Studies on microplasmodia of Physarum polycephalum V: Electrical activity of dierent types of micro-
plasmodia and macroplasmodia. Cell Biol. Int. Rep. 3, 321–330 (1979).
36. Trebacz, K., Dziubinska, H. & Krol, E. Electrical signals in long-distance communication in plants. In Communication in plants,
277–290 (Springer, 2006).
37. Fromm, J. & Lautner, S. Electrical signals and their physiological signicance in plants. Plant Cell Environ. 30, 249–257 (2007).
38. Zimmermann, M.R. & Mithöfer, A. Electrical long-distance signaling in plants. In Long-Distance Systemic Signaling and Com-
munication in Plants, 291–308 (Springer, 2013).
39. Simons, P. e role of electricity in plant movements. New Phytol. 87, 11–37 (1981).
40. Fromm, J. Control of phloem unloading by action potentials in mimosa. Physiol. Plant. 83, 529–533 (1991).
41. Sibaoka, T. Rapid plant movements triggered by action potentials. Bot. Mag. = Shokubutsu-gaku-zasshi 104, 73–95 (1991).
42. Volkov, A. G. et al. Mimosa pudica: Electrical and mechanical stimulation of plant movements. Plant Cell Environ. 33, 163–173
(2010).
43. Minorsky, P. Temperature sensing by plants: A review and hypothesis. Plant Cell Environ. 12, 119–135 (1989).
44. Volkov, A. G. Green plants: electrochemical interfaces. J. Electroanal. Chem. 483, 150–156 (2000).
45. Roblin, G. Analysis of the variation potential induced by wounding in plants. Plant Cell Physiol. 26, 455–461 (1985).
46. Pickard, B. G. Action potentials in higher plants. Bot. Rev. 39, 172–201 (1973).
47. Whittaker, R. H. On the broad classication of organisms. Q. Rev. Biol. 34, 210–226 (1959).
48. Talbot, P. Fungi with a plasmodial thallus division myxomycota: Slime-moulds. In Principles of Fungal Taxonomy, 99–108 (Springer,
1971).
49. Bruns, T. D., White, T. J. & Taylor, J. W. Fungal molecular systematics. Annu. Rev. Ecol. Syst. 22, 525–564 (1991).
50. Jan, L. Y. & Jan, Y. N. How might the diversity of potassium channels be generated?. Trends Neurosci. 13, 415–419 (1990).
51. Kindler, C. H., Yost, S. C. & Gray, A. T. Local anesthetic inhibition of baseline potassium channels with two pore domains in
tandem. J. Am. Soc. Anesthesiol. 90, 1092–1102 (1999).
52. Steinberg, E., Waord, K., Brickley, S., Franks, N. & Wisden, W. e role of k 2p channels in anaesthesia and sleep. Pügers Archiv-
Eur. J. Physiol. 467, 907–916 (2015).
Acknowledgements
is project has received funding from the European Union’s Horizon 2020 research and innovation pro-
gramme FET OPEN “Challenging current thinking” under grant agreement No 858132. e authors would like
to acknowledge the collaboration of Mogu S.r.l. providing the living materials used in the experiments. At the
time of experiments AG was aliated with Mogu S.r.l., Inarzo, Italy. All the experiments have been conducted
in the Unconventional Computing Lab, UWE, Bristol.
Content courtesy of Springer Nature, terms of use apply. Rights reserved
8
Vol:.(1234567890)
Scientic Reports | (2022) 12:340 | https://doi.org/10.1038/s41598-021-04172-0
www.nature.com/scientificreports/
Author contributions
A.A. and A.G. conducted and analysed experiments. A.A. and A.G. wrote the paper.
Competing interests
e authors declare no competing interests.
Additional information
Correspondence and requests for materials should be addressed to A.A.
Reprints and permissions information is available at www.nature.com/reprints.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and
institutional aliations.
Open Access is article is licensed under a Creative Commons Attribution 4.0 International
License, which permits use, sharing, adaptation, distribution and reproduction in any medium or
format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the
Creative Commons licence, and indicate if changes were made. e images or other third party material in this
article are included in the articles Creative Commons licence, unless indicated otherwise in a credit line to the
material. If material is not included in the article’s Creative Commons licence and your intended use is not
permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from
the copyright holder. To view a copy of this licence, visit http:// creat iveco mmons. org/ licen ses/ by/4. 0/.
© e Author(s) 2022
Content courtesy of Springer Nature, terms of use apply. Rights reserved
1.
2.
3.
4.
5.
6.
Terms and Conditions
Springer Nature journal content, brought to you courtesy of Springer Nature Customer Service Center GmbH (“Springer Nature”).
Springer Nature supports a reasonable amount of sharing of research papers by authors, subscribers and authorised users (“Users”), for small-
scale personal, non-commercial use provided that all copyright, trade and service marks and other proprietary notices are maintained. By
accessing, sharing, receiving or otherwise using the Springer Nature journal content you agree to these terms of use (“Terms”). For these
purposes, Springer Nature considers academic use (by researchers and students) to be non-commercial.
These Terms are supplementary and will apply in addition to any applicable website terms and conditions, a relevant site licence or a personal
subscription. These Terms will prevail over any conflict or ambiguity with regards to the relevant terms, a site licence or a personal subscription
(to the extent of the conflict or ambiguity only). For Creative Commons-licensed articles, the terms of the Creative Commons license used will
apply.
We collect and use personal data to provide access to the Springer Nature journal content. We may also use these personal data internally within
ResearchGate and Springer Nature and as agreed share it, in an anonymised way, for purposes of tracking, analysis and reporting. We will not
otherwise disclose your personal data outside the ResearchGate or the Springer Nature group of companies unless we have your permission as
detailed in the Privacy Policy.
While Users may use the Springer Nature journal content for small scale, personal non-commercial use, it is important to note that Users may
not:
use such content for the purpose of providing other users with access on a regular or large scale basis or as a means to circumvent access
control;
use such content where to do so would be considered a criminal or statutory offence in any jurisdiction, or gives rise to civil liability, or is
otherwise unlawful;
falsely or misleadingly imply or suggest endorsement, approval , sponsorship, or association unless explicitly agreed to by Springer Nature in
writing;
use bots or other automated methods to access the content or redirect messages
override any security feature or exclusionary protocol; or
share the content in order to create substitute for Springer Nature products or services or a systematic database of Springer Nature journal
content.
In line with the restriction against commercial use, Springer Nature does not permit the creation of a product or service that creates revenue,
royalties, rent or income from our content or its inclusion as part of a paid for service or for other commercial gain. Springer Nature journal
content cannot be used for inter-library loans and librarians may not upload Springer Nature journal content on a large scale into their, or any
other, institutional repository.
These terms of use are reviewed regularly and may be amended at any time. Springer Nature is not obligated to publish any information or
content on this website and may remove it or features or functionality at our sole discretion, at any time with or without notice. Springer Nature
may revoke this licence to you at any time and remove access to any copies of the Springer Nature journal content which have been saved.
To the fullest extent permitted by law, Springer Nature makes no warranties, representations or guarantees to Users, either express or implied
with respect to the Springer nature journal content and all parties disclaim and waive any implied warranties or warranties imposed by law,
including merchantability or fitness for any particular purpose.
Please note that these rights do not automatically extend to content, data or other material published by Springer Nature that may be licensed
from third parties.
If you would like to use or distribute our Springer Nature journal content to a wider audience or on a regular basis or in any other manner not
expressly permitted by these Terms, please contact Springer Nature at
onlineservice@springernature.com
ResearchGate has not been able to resolve any citations for this publication.
Article
Full-text available
We recorded extra-cellular electrical potential of fruit bodies of oyster fungi Pleurotus djamor. We demonstrated that the fungi generate action potential like impulses of electrical potential. Trains of the spikes are observed. Two types of spiking activity are uncovered: high-frequency (period 2.6 min) and low-frequency (period 14 min); transitions between modes of spiking are illustrated. An electrical response of fruit bodies to short (5 sec) and long (60 sec) thermal stimulation with open flame is analysed in details. We show that non-stimulated fruit bodies of a cluster react to the thermal stimulation, with a single action-potential like spike, faster than the stimulated fruit body does.
Article
Full-text available
Action potentials (APs) belong to long-distance signals in plants. They fulfill the all-or-none law, propagate without decrement and their generation is limited by refractory periods. The ion mechanism of APs was elaborated in giant Characean algae and extended by another model plant - the liverwort Conocephalum conicum. It consists of an increase in cytoplasmic Ca2+ concentration ([Ca2+]cyt) which activates anion channels responsible for Cl- efflux and for membrane depolarization. Repolarization occurs after the opening of potassium channels and K+ efflux. The resting potential is restored by the electrogenic proton pump. A number of ion channels which may play a role in AP were identified by the patch-clamp technique. APs propagate on the principle of local electrical circuits. They cover whole plants, plant organs or definite tissues, mainly phloem, phloem parenchyma and protoxylem. APs mediate between local stimulation and movements in carnivorous Dionaea muscipula, Aldrovanda vesiculosa, and tigmonastic Mimosa pudica. The role of APs in regulation of respiration, photosynthesis, growth, pollination, fertilization and gene expression is well documented. An AP-coupled increase in [Ca2+]cyt seems to play a central role in signal transduction.
Article
Full-text available
Tandem two-pore potassium channels (K2Ps) have widespread expression in the central nervous system and periphery where they contribute to background membrane conductance. Some general anaesthetics promote the opening of some of these channels, enhancing potassium currents and thus producing a reduction in neuronal excitability that contributes to the transition to unconsciousness. Similarly, these channels may be recruited during the normal sleep-wake cycle as downstream effectors of wake-promoting neurotransmitters such as noradrenaline, histamine and acetylcholine. These transmitters promote K2P channel closure and thus an increase in neuronal excitability. Our understanding of the roles of these channels in sleep and anaesthesia has been largely informed by the study of mouse K2P knockout lines and what is currently predicted by in vitro electrophysiology and channel structure and gating.
Article
Full-text available
The French scientist Claude Bernard (1813-1878) is famous for his discoveries in physiology and for introducing rigorous experimental methods to medicine and biology. One of his major technical innovations was the use of chemicals in order to disrupt normal physiological function to test hypotheses. But less known is his conviction that the physiological functions of all living organisms rely on the same underlying principles. He hypothesized that similarly to animals, plants are also able to sense changes in their environment. He called this ability "sensitivity." In order to test his ideas, he performed anesthesia on plants and the results of these experiments were presented in 1878 in "Leçonssur les phénomènes de la vie communs aux animaux et aux végétaux." (1) The phenomena described by Claude Bernard more than a century ago are not fully understood yet. Here, we present a short overview of anesthetic effects in animals and we discuss how anesthesia affects plant movements, seed germination, and photosynthesis. Surprisingly, these phenomena may have ecological relevance, since stressed plants generate anesthetics such as ethylene and ether. Finally, we discuss Claude Bernard's interpretations and conclusions in the perspective of modern plant sciences.
Article
Full-text available
The travelling salesman problem (TSP) is a well known and challenging combinatorial optimisation problem. Its computational intractability has attracted a number of heuristic approaches to generate satisfactory, if not optimal, candidate solutions. Some methods take their inspiration from natural systems, extracting the salient features of such systems for use in classical computer algorithms. In this paper we demonstrate a simple unconventional computation method to approximate the Euclidean TSP using a virtual material approach. The morphological adaptation behaviour of the material emerges from the low-level interactions of a population of particles moving within a diffusive lattice. A ‘blob’ of this material is placed over a set of data points projected into the lattice, representing TSP city locations, and the blob is reduced in size over time. As the blob shrinks it morphologically adapts to the configuration of the cities. The shrinkage process automatically stops when the blob no longer completely covers all cities. By manually tracing the perimeter of the blob a path between cities is elicited corresponding to a TSP tour. Over 10 runs on 20 randomly generated datasets consisting of 20 cities this simple and unguided method found tours with a mean average tour length of 6.41 % longer than the minimum tours computed by a TSP solver (mean best performance was 4.27 % longer and mean worst performance was 9.22 % longer). We examine the insertion mechanism by which the blob constructs a tour, note some properties and limitations of its performance, and discuss the relationship between the blob TSP and proximity graphs which group points on the plane. The method is notable for its simplicity, novelty and the spatially represented mechanical mode of its operation. We discuss similarities between this method and previously suggested models of human performance on the TSP and suggest possibilities for further improvement.
Chapter
Two distinct phases occur in the life-cycle of a slime-mould. First there is an active assimilative phase in which the thallus, a protozoa-like amoeboid plasmodium, moves with a creeping motion and feeds either saprobically or holozoically by engulfing and digesting bacteria or other solid particles in food vacuoles formed according to need. Second, there is a quiescent phase in which the protoplasm of the plasmodium becomes concentrated into fungus-like sporangia with dry sporangiospores which are meiosporous in their formation. Hyphae are not formed at any time in the life-cycle. Because they appear to have affinities with protozoa and with fungi, the slime-moulds have always been peculiarly difficult to classify. Further difficulties arise because some slime-moulds (Class Myxomycetes) are free-living while others (Class Plasmodiophoromycetes) are endoparasites in cells of higher plants and also differ in several other respects from the free-living types. In addition, two other Orders of slime-organisms, the Acrasiales and the Labyrinthulales, are often considered in this context.
Chapter
In higher plants at least three different types of electrical long-distance signaling exist: action potential (AP), variation potential (VP), and system potential (SP), all of which have their own characteristics concerning their generation, duration, amplitude, velocity, and propagation. Whereas both AP and VP are due to a transient depolarization of the plasma membrane, the SP is based on hyperpolarization. For more than 100 years the AP is known and described for some specialized plants such as the Venus flytrap. Meanwhile, all three types of electrical signaling have been shown for many common plants, monocots as well as dicots, indicating that the capability to generate long-distance electrical signals is not the exception but a general physiological feature of plants. In spite of this, positive proofs for the involvement of these kinds of electrical signaling in the induction of many different plant responses to (a)biotic stresses or in developmental processes still wait to be established.
Article
Following burning of a leaf portion, a bioelectrical wave called “variation potential” spread throughout the whole plant. Bioelectrical variations are recorded by two types of electrodes (platinum wires and Ag/AgCl nonpolarizable electrodes) in the stem of Vicia faba and in the petiole of Lycopersicon esculentum and Mimosa pudica. The time course of the variation potential thus recorded can be divided into two components respectively called components “A” and “B”. Component A looks like a negative spiky bioelectrical change lasting about 1 min with an amplitude of 20–50 mV spreading in front of the component B depicted by a more smooth and long-lasting (several min) wave of negativity. An attenuation of the signals recorded under the Ag/AgCl electrodes is noted compared to that recorded under the platinum wires. Moreover, component B is more attenuated than the component A. Attenuation of the component A is nearly the same as that noted for the action potential in Mimosa pudica. All the parameters depicting the variation potential increase approximately in direct proportion to the amount of the damaged area up to 400 mm² in Vicia faba; above this value, a maximal response is reached.