Noise-like activity (NLA) refers to spontaneous subthreshold fluctuations in membrane potential. In this thesis, we examine the role that synaptic channel fluctuations play in contributing to NLA by comparing a detailed biophysical model to experimental data from whole-intact hippocampal interneurons. To represent the contribution from synaptic channel fluctuations, we switch the synapses in the model from traditional to Markovian formalisms and demonstrate statistically relevant increases the standard deviation; power-law scaling exponent; and power spectral density in the 5-100 Hz and 1-5 kHz ranges. However, while synaptic channel fluctuations have a definite effect, we found that they were significantly more subtle than the synaptic response to network activity. This indicates that synaptic channel fluctuations do indeed play a significant role in subthreshold noise, but, overall, synaptic NLA is dominated by the synaptic response to presynaptic network activity.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/18882 |
| Date | 15 February 2010 |
| Creators | Stanley, David |
| Contributors | Bardakjian, Berj |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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