Evolved not engineered: a systems neurobiology

1,860 views

Published on

The design or engineering approaches to evolution are numerous: the Lee Hood's automobile paradigm, the camera eye, the input-output brain, the blind watchmaker, etc. These approaches have been useful in their time, but because biological organisms are evolved, not engineered, their usefulness is about as limited as Newtonian Mechanics in contemporary physics.

Published in: Education, Technology
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
1,860
On SlideShare
0
From Embeds
0
Number of Embeds
4
Actions
Shares
0
Downloads
10
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

Evolved not engineered: a systems neurobiology

  1. 1. Evolved not engineered: a systemsneurobiology<br />Björn Brembs<br />http://brembs.net<br />Freie Universität Berlin, Institut für Biologie – Neurobiologie<br />Königin-Luise Str. 28/30, 14195 Berlin, Germany. <br />Email: bjoern@brembs.net, phone: +49 (0)30 838 55050, fax: +49 (0)30 838 55455<br />
  2. 2. Systems Biology<br />Björn Brembs, Freie Universität Berlin, http://brembs.net<br />2<br />Lee Hood‘s Automobile Paradigm<br />
  3. 3. Gene Networks<br />Engineeredsystemsentailstablenetworkinteractions<br />Björn Brembs, Freie Universität Berlin, http://brembs.net<br />3<br /> M. Costanzo et al., Science 327, 425-431 (2010) <br />
  4. 4. Clockwork<br />Are Biological OrganismsEngineered?<br />
  5. 5. How Stable Are Gene Interactions?<br />Phenotypeofthetemperature sensitive Syntaxin-1A (Syx1A) mutant:<br />Björn Brembs, Freie Universität Berlin, http://brembs.net<br />5<br />% standing<br />time<br />39°C<br />25°C<br />van Swinderen & Greenspan (2005)<br />
  6. 6. Screening forsyxSuppressors<br />Isolating mutants extending the time standing at 39°C over Syx1A<br />Björn Brembs, Freie Universität Berlin, Institut für Biologie - Neurobiologie. http://brembs.net<br />6<br />Syx-<br />+<br />% standing<br />Syx-Sup<br />+ +<br />time at 39°C<br />van Swinderen & Greenspan (2005)<br />
  7. 7. Quantifying Gene Interactions<br />In thewildtypebackground…<br />Björn Brembs, Freie Universität Berlin, Institut für Biologie - Neurobiologie. http://brembs.net<br />7<br />expected<br />observed<br />Sup1Sup2<br />+ +<br />Sup1Sup2<br />+ +<br />…and in theSyx-background<br />Syx-<br />+<br />% standing<br />Syx-<br /> +<br />time at 39°C<br />van Swinderen & Greenspan (2005)<br />
  8. 8. A Gene Interaction Matrix <br />The genematrix in WT background<br />8<br />The genematrix in Syx-background<br />previous interaction<br />positive interaction<br />missing interaction<br />negative interaction<br />reversed sign<br />new interaction<br />
  9. 9.
  10. 10. Octopamine and Insect Flight<br />OA isthe relevant amine<br />Flies without OA fly well<br />Flies withblocked TA receptorsfly well<br />Flies without OA and TA do notfly well<br />Björn Brembs, Freie Universität Berlin, http://brembs.net<br />10<br />Brembs et al. (2007)<br />
  11. 11. Robustness by Degeneracy<br />30% ofmurineandupto 50% ofyeastgene knock-outsarewithoutphenotype.<br />redundant<br />degenerate<br />
  12. 12. Neural Networks<br />Do neuralnetworksbehavelikegenenetworks?<br />
  13. 13. General Brain Function<br />
  14. 14. Input-Output<br />I reacttoexternalstimuli, therefore I am?<br />
  15. 15. SquidEscapeBehavior<br />
  16. 16. Loligogiantaxons<br />www.mbl.edu<br />Electrode in giantaxon<br />
  17. 17. Fish C-start Response<br />
  18. 18. TentacleSnakespredictfishresponse<br />
  19. 19. Fly Escape Response<br />
  20. 20. PaintedRedstartspredictflyresponse<br />
  21. 21. Predictability<br />Being predictable is not evolutionary stable<br />
  22. 22. DegreesofPredictability<br />Evoked<br />Fixed stimulus/responseatfixedlatency<br />e.g. reflex<br />Mixed<br />Complexstimuli/variable actions<br />Behavioralset<br />Endogenousevokedresponses<br />Closedloop<br />Predictability<br />Spontaneous<br />Activityindependentofsensoryinput<br />e.g. exploration<br />Stimulus-responsecoupling<br />
  23. 23. Degreesof Efficiency<br />Evoked<br />Fixed stimulus/responseatfixedlatency<br />e.g. reflex<br />/ Efficiency<br />Mixed<br />Complexstimuli/variable actions<br />Behavioralset<br />Endogenousevokedresponses<br />Closedloop<br />Predictability<br />Spontaneous<br />Activityindependentofsensoryinput<br />e.g. exploration<br />Stimulus-responsecoupling<br />
  24. 24. Psychological Challenge<br />Response<br />Action<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />24<br />
  25. 25. Ecological Challenge<br />Exploitation<br />Exploration<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />25<br />
  26. 26. Evolutionary Challenge<br />Optimality<br />Flexibility<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />26<br />
  27. 27. Reafferent Feedback<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />27<br />
  28. 28. General brainfunction<br />Action – Outcome Evaluation<br />
  29. 29. Drosophila Turning<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />29<br />Behavioralvariability in a constantstimulussituation:<br />Actions, not responses<br />
  30. 30. Drosophila Turning<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />30<br />Behavioralvariability in a constantstimulussituation:<br />Actions, not responses<br />
  31. 31. Choice or Noise?<br />Decisionsor just noise in complexstimulus-responsesystems?<br />
  32. 32. Choice or Noise?<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />32<br />Maye et al. (2007) PLoSOne<br />Geometric Random Inner Products: GRIP<br />
  33. 33. Choice or Noise?<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />33<br />correlation<br />nonlinearity<br />Maye et al. (2007) PLoSOne<br />Nonlinear (choice)<br />Linear/stochastic (noise)<br />
  34. 34. Choice or Noise?<br />Maye et al. (2007) PLoSOne<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />34<br />
  35. 35. Choice or Noise?<br />Nonlineardecision-makingsystem underlies spontaneity in flies<br />
  36. 36. spontaneity<br />Whatarethefunctionsofspontaneousbehavioralvariability?<br />
  37. 37. Pursuit-evasioncontests& competition (courtship, predator-prey, territoriality, chess, sports etc.)<br />
  38. 38. Exploration (find thathiddenresourceyouwouldotherwisenever find.)<br />
  39. 39. Detectionofre-afferent signals in thesensorystream (trytotickleyourself!) -> operant behavior/learning<br />
  40. 40. Reafferent Feedback<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />40<br />
  41. 41. BehavioralVariability<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />41<br />
  42. 42. BehavioralOutcomes<br />operant<br />self<br />classical<br />world<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />42<br />
  43. 43. Operant conditioning<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />43<br />
  44. 44. Action - Outcome Evaluation<br />Brembs & Plendl (2008) CurrentBiology<br />rut-AC dependentSynapticPlasticity<br />Protein Kinase C<br />world<br />self<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />44<br />
  45. 45. Conservation<br />PKC but not rut-AC involved in Aplysiaself-learning<br />Aplysiacalifornica<br />F. Lorenzetti, D. Baxter, J. Byrne (2008): Neuron 59, 815-828<br />
  46. 46. Action – Outcome Evaluation<br />FoxP2<br />Language learning<br />
  47. 47. 13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />47<br />FoxPisNecessaryforSelf-Learning<br />
  48. 48. PKC/FoxPrequiredforSelf-Learning<br />FoxP<br />PKC<br />Not required<br />Not required<br />Required<br />Required<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />48<br />
  49. 49. Two Components<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />49<br />
  50. 50. Multiple Memories<br />Whyhavemorethanonelearningsystem?<br />
  51. 51. Evolutionary Dilemma<br />Exploitation<br />Exploration<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />51<br />
  52. 52. Multiple Learning Systems<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />52<br />
  53. 53. From Exploration toExploitation<br />Brembs (2009)<br />
  54. 54. Reciprocal, Hierarchical Interactions<br />Facilitation:<br />Learning-by-doing<br />Inhibition:<br />Regulateshabitformation/generalization :<br />Exploitation<br />Exploration<br />13.07.2010<br />Björn Brembs, Freie Universität Berlin<br />54<br />
  55. 55. General FLY brainfunction<br />Action – Outcome Evaluation<br />
  56. 56. Gáspár Jékely<br />Ancestral: Stimulus-Response?<br />Max Planck Institute for Developmental Biology<br />Phototaxis<br />Polychaete: Platynereisdumerilii<br />
  57. 57. Ancestral: Stimulus-Response?<br />Phototaxis<br />Stimulus – Response<br />Sensoryneurons – Ciliatedcells<br />Polychaete: Platynereisdumerilii<br />
  58. 58. Phototaxis: Stimulus-Response?<br />Behavior (action)<br />Stimuli inhibitormodulateaction<br />Result: Phototaxis<br />G Jékelyet al.Nature456, 395-399 (2008) doi:10.1038/nature07590<br />
  59. 59. Ancestral State<br />Ongoingactivitymodulatedbyexternalstimuli<br />
  60. 60. The Default Mode Network<br />The limitingfactor in theevolutionofbrainsize was energysupply<br />60<br />
  61. 61. The Default Mode Network<br />The limitingfactor in theevolutionofbrainsize was energysupply<br />61<br />The additional energyburdenassociatedwith […] theenvironmentmaybeaslittleas .5-1.0% ofthe total energybudget.<br />Marcus Raichle (2006): Science314, p1249<br />
  62. 62. Human State<br />Ongoingactivitymodulatedbyexternalstimuli<br />
  63. 63. The Engineering Approach toBiology<br />Can beseenasanalogoustoNewtonianMechanics in physics<br />
  64. 64. Standing on the shoulder of giants…<br />Teachers & Collaborators<br />Flight performance:<br />Carsten Duch<br />Frauke Christiansen<br />Jochen Pflüger<br />Fly learning:<br />Wolfgang Plendl<br />Jan Wiener<br />Natalie Hempel de Ibarra<br />Troy Zars<br />Reinhard Wolf<br />Martin Heisenberg<br />Teachers:<br /><ul><li>Martin Heisenberg
  65. 65. Jack Byrne
  66. 66. Randolf Menzel
  67. 67. Bernard Balleine
  68. 68. Ralph Greenspan
  69. 69. George Sugihara
  70. 70. Bill Kristan
  71. 71. David Glanzman
  72. 72. Eric Kandel
  73. 73. Jochen Pflüger
  74. 74. Ed Kravitz
  75. 75. Richard Morris
  76. 76. Hans-Peter Lipp
  77. 77. David Wolfer
  78. 78. Barry Keverne
  79. 79. KlaudeWeiss
  80. 80. Cathy Rankin</li></ul>Aplysiaconditioning:<br />Fred Lorenzetti<br />Riccardo Mozzachiodi<br />VuHyun<br />Elizabeth Wilkinson<br />Fredy Reyes<br />Jack Byrne<br />Aplysiaimaging:<br />Quentin Gaudry<br />William Kristan<br />Fly spontaneity:<br />Alexander Maye<br />ZacHsieh<br />George Sugihara<br />Fly aggression:<br />Britta Wittek<br />Andrea Baier<br />Ed Kravitz<br />Fly attention:<br />Bruno van Swinderen<br />

×