Seminar Computational Intelligence F (708.116)

SS 2012

Institut f�r Grundlagen der Informationsverarbeitung (708)

Assoc. Prof. Dr. Robert Legenstein

Office hours: by appointment (via e-mail)

E-mail: robert.legenstein@igi.tugraz.at
Homepage: www.igi.tugraz.at/legi/

Location: IGI-seminar room, Inffeldgasse 16b/I, 8010 Graz
Date: starting on March 15th 2012, every Thursday, 16.15 - 18.00

Content of the seminar:

In this seminar, we will discuss new results on synaptic plasticity. Most theoretical models of synaptic plasticity focus on point neuron models. However, cortical pyramidal neurons have quite stereotypical dendritic branches with nonlinear effects such as dendritic spikes of various types. Also, synaptic input from different sources target different dendritic locations, and synaptic plasticity rules depend on the dendritic location of the synapse. Collectively, these findings suggests that pyramidal neurons (in particular: cortical Layer 5 pyramidal neurons) are specialized plastic processors that integrate information and adapt to information from different sources in a specific way.
We will furthermore look at new results about modulation of plasticity by dopamine and inhibition, as well as clustered plasticity models.

Talks:

24.05.2012
David Kappel:	about: "Conditional modulation of spike-timing-dependent plasticity for olfactory learning" Slides;

05.06.2012 (Tuesday)
Johannes Bill:	about: "Observation on clustered synaptic plasticity and highly structured input patterns"
	about: "A clustered plasticity model of long-term memory engrams" Slides;
Zeno Jonke:	about: "Learning with two sites of synaptic integration" Slides;

14.06.2012
	Bahram Yoosefizonooz:	about: "A new cellular mechanism for coupling inputs arriving at different cortical layers"
	about: "Dentritic mechanisms controlling spike-timing-dependent synaptic plasticity" Slides;
Elmar R�ckert:	about: "Synaptic integration in tuft dendrites of layer 5 pyramidal neurons: A new unifying principle" Slides;

21.06.2012
Stefan Habenschuss:	about: "Micro-rewiring as a substrate for learning" Slides;
Elahe Arani:	about: "Supervised and unsupervised learning with two sites of synaptic integration" Slides;

28.06.2012
Martin Ratajczak:	about: "Active dentrites: adaptation to spike-based communication" Slides;

5.07.2012
Jing Fang:	about: "Amygdala inhibitory circuits and the control of fear memory" Slides;
Johanna Wagner	about: "Dopamine gates LTP induction in lateral amygdala by suppressing feedforward inhibition" Slides;

Literature:

Papers on plasticity in Layer 5 Pyramids (L5Ps):

1.)	Kampa BM, Letzkus JJ, and Stuart GJ. Dendritic mechanisms controlling spike-timing-dependent synaptic plasticity. Trends in Neurosciences, 30(9):456-463, 2007.
	This is a very readable paper. It builds on

2.)	Letzkus JJ, Kampa BM, and Stuart GJ. Learning rules for spike timing-dependent plasticity depend on dendritic synapse location. J Neurosci. 2006 Oct 11;26(41):10420-9.
	This paper provides further details.

Talks on these papers should be preceded by:

3.)	Larkum ME, Zhu JJ, and Sakmann B. A new cellular mechanism for coupling inputs arriving at different cortical layers. Nature, 398:338-341, 1999
	which describes the BAC firing mechanism, and

4.)	Larkum ME, Nevian T, Sandler M, Polsky A, and Schiller J. Synaptic integration in tuft dendrites of layer 5 pyramidal neurons: A new unifying principle. Science, 325:756-760, 2009.
	Here, the authors describe an inspiring hypothesis about computation in L5Ps.

The following papers may have modeled some of the consequences of these mechanisms (needs to be checked):

5.)	K�rding KP and K�nig P. Learning with two sites of synaptic integration Network: Computation in neural Systems, 2000 http://www.tandfonline.com/doi/abs/10.1088/0954-898X_11_1_302

6.)	K�rding KP and K�nig P. Supervised and unsupervised learning with two sites of synaptic integration- Journal of Computational Neuroscience, 2001 https://link.springer.com/article/10.1023%2FA%3A1013776130161?LI=true

7.)	Siegel M, K�rding KP, and K�nig P. Integrating top-down and bottom-up sensory processing by somato-dendritic interactions - Journal of computational neuroscience, 2000 http://www.ini.uzh.ch/~peterk/OwnPapers/siegel.jcns.00.pdf
	which describes the BAC firing mechanism, and

Modulation of plasticity by dopamine and inhibition:

8.)	Xu TX and Yao WD. D1 and D2 dopamine receptors in separate circuits cooperate to drive associative long-term potentiation in the prefrontal cortex. Proc Natl Acad Sci U S A. 2010 Sep 14;107(37):16366-71. http://www.ncbi.nlm.nih.gov/pubmed/20805489
	This paper suggests that DA affects syn. plasticity in L5Ps in PFC by reducing the impact of inhibitory neurons, that otherwise prevent synaptic plasticity.

9.)	Bissi�re S, Humeau Y, and L�thi A. Dopamine gates LTP induction in lateral amygdala by suppressing feedforward inhibition. Nat Neurosci. 2003 Jun;6(6):587-92. http://www.ncbi.nlm.nih.gov/pubmed/12740581.
	This paper tells us a similar story for Amygdala.

10.)	Ehrlich I, Humeau Y, Grenier F, Ciocchi S, Herry C, and L�thi A. Amygdala inhibitory circuits and the control of fear memory. Neuron. 2009 Jun 25;62(6):757-71. http://www.ncbi.nlm.nih.gov/pubmed/19555645
	A review paper on this topic.

11.)	Cassenaer S and Laurent G. Conditional modulation of spike-timing-dependent plasticity for olfactory learning. Nature, 25 January 2012.

Papers on clustered plasticity:

12.)	Magee JC. Observations on clustered synaptic plasticity and highly structured input patterns. Neuron. 2011 Dec 22;72(6):887-8
	The paper provides a nice recent review of "clustered plasticity". It is quite short, so it should be complemented by more detailed papers such as.

13.)	DeBello WM. Micro-rewiring as a substrate for learning, TINS 2008.

14.)	Govindarajan A, Kelleher RJ, and Tonegawa S. A clustered plasticity model of long-term memory engrams. Nature Reviews Neuroscience, 7:575-583, 2006.

Theoretical model for dendritic computation:

15.)	Ujfalussy B. B., Lengyiel M. Acitve dendrites: adaptation to spike-based communication.