Bock Paper - Neuron Question

[adjordan]

If they only had 14 neurons, how many were inhibitory? Doesn't that effect results?

[adjordan]

Nevermind, Maxwell just asked this. We didn't come to a solid conclusion.

[sgomezr]

I though it was only one (one interneuron, 13 excitatory neurons). Quoting the paper (page 178, second column, first paragraph - up right corner): "Thirteen of the cells were selective for stimulus orientation. The fourteenth neuron was visually responsive, but non-selective for orientation. It had a non-pyramidal neuronal morphology, received a symmetric contacts onto the cell body, and made symmetric synapses onto its postsynaptic targets (Supplementary Fig. 4), suggesting it was an inhibitory, GABAergic interneuron33. Both the precision of physical registration and the alignment of appropriate functional properties with neuronal morphology (orientation selective excitatory cells and an unselective inhibitory neuron) demonstrate that we successfully combined micrometre-scale in vivo functional imaging and nanometre-scale EM ultrastructure".

Yet, that was only for the small group they decided to analyze.

They originally had way more excitatory neurons and interneurons: 'We categorized the postsynaptic targets as either excitatory or inhibitory on the basis of morphology. Pyramidal cell dendrites were densely studded with spines, whereas inhibitory interneuron dendrites were sparsely spinous and receive more asymmetric (excitatory) synapses their dendritic shafts33. Of 245 synapses originating from 10 functionally characterized pyramidal neurons that made synapses in the EM-imaged volume, 125 (51%) were onto inhibitory dendrites and 120 (49%) onto excitatory dendrites. Of the 185 distinct postsynaptic targets, 71 (38%) were inhibitory (Fig. 5, cyan) and 114 (62%) were excitatory (Fig. 5, magenta)'.