RT Journal Article
SR Electronic
T1 Modeling unitary fields and the single-neuron contribution to local field potentials in the hippocampus
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 602953
DO 10.1101/602953
A1 Maria Teleńczuk
A1 Bartosz Teleńczuk
A1 Alain Destexhe
YR 2019
UL http://biorxiv.org/content/early/2019/04/15/602953.abstract
AB Synaptic currents represent a major contribution to the local field potential (LFP) in brain tissue, but the respective contribution of excitatory and inhibitory synapses is not known. Here, we provide estimates of this contribution by using computational models of hippocampal pyramidal neurons, constrained by in vitro recordings. We focus on the unitary LFP (uLFP) generated by single neurons. We first reproduce experimental results for hippocampal basket cells, and in particular how inhibitory uLFP are disrtributed within hippocampal layers. Next, we calculate the uLFP generated by pyramidal neurons, using morphologically-reconstructed CA3 pyramidal cells. The model shows that the excitatory uLFP is of small amplitude, smaller than inhibitory uLFPs. Indeed, when the two are simulated together, inhibitory uLFPs mask excitatory uLFPs, which might create the illusion that the inhibitory field is generated by pyramidal cells. These results provide an explanation for the observation that excitatory and inhibitory uLFPs are of the same polarity, in vivo and in vitro. These results also show that somatic inhibitory currents are large contributors of the LFP, which is important information to interpret this signal. Finally, the results of our model might form the basis of a simple method to compute the LFP, which could be applied to point neurons for each cell type, thus providing a simple biologically-grounded method to calculate LFPs from neural networks.