First report

I’ve started the PhD on 1st October 2010. This is the first in the series of weekly reports, so it’s probably going to be a bit longer.

So far I have been looking into the literature on synaptic integration in general and more specifically on the influence of noise on the integration (find the list of papers I have been reading below).

As you can see from the list of papers, I was mainly focussing on the work of Destexhe with synaptic background activity as the source of noise. For this we planned to first computationally reproduce their results (responsiveness of pyramidal neurons in the presence of background activity is increased and becomes probabilistic [2,4,7]). Then we could use this model (or at least the lessons learned) to study the ability of neuron to differentiate synaptic input sequences and/or dependence of responses on the input location.

We had a Skype meeting (with Mark and Clemens) and discussed this idea, where Clemens gave us the overview on the current status on realistic neuron activity in leaving mammals, conflicting with Destexhe assumption of high-conductance state of neocortical neurons in vivo. This calls for rethinking and some more literature reading.

I also started using neuron and Morphforge, which is a set of convenience interface scripts developed by Michael Hull. This seems like a great tool for further modelling work.

References:
1. van Rossum M, O’Brien BJ, Smith RG. Effects of Noise on the Spike Timing Precision of Retinal Ganglion Cells. J Neurophysiol. 2003;89(5):2406-2419.
2. Destexhe A, Rudolph M, Pare D. The high-conductance state of neocortical neurons in vivo. Nat Rev Neurosci. 2003;4(9):739-751.
3. Faisal AA, Selen LPJ, Wolpert DM. Noise in the nervous system. Nat Rev Neurosci. 2008;9(4):292-303.
4. Destexhe A, Pare D. Impact of Network Activity on the Integrative Properties of Neocortical Pyramidal Neurons In Vivo. J Neurophysiol. 1999;81(4):1531-1547.
5. Jia H, Rochefort NL, Chen X, Konnerth A. Dendritic organization of sensory input to cortical neurons in vivo. Nature. 2010;464(7293):1307-1312.
6. Branco T, Clark BA, Häusser M. Dendritic discrimination of temporal input sequences in cortical neurons. Science. 2010;329(5999):1671-1675.
7. Ho N, Destexhe A. Synaptic Background Activity Enhances the Responsiveness of Neocortical Pyramidal Neurons. J Neurophysiol. 2000;84(3):1488-1496.
8. Boucsein C, Nawrot M, Rotter S, Aertsen A, Heck D. Controlling Synaptic Input Patterns In Vitro by Dynamic Photo Stimulation. J Neurophysiol. 2005;94(4):2948-2958.