Are there any brain region connection data at a more microscopic scale?

I am looking to obtain relatively microscopic-scale connection data for the mouse olfactory bulb, cerebral cortex, and hippocampus (either specific floating-point connection weights or binary connection status, i.e., whether there is a connection or not). I noticed that the data provided at “https://connectivity.brain-map.org/” for these three brain regions only amounts to a few thousand. However, I am seeking more microscopic-scale and extensive data, such as tens of thousands or even hundreds of thousands of connections (finer divisions, even at the synaptic level). I saw on MICRONS EXPLORER that they have obtained over a hundred million synaptic connection data for the primary visual cortex. Has anyone produced synaptic-level data for the olfactory bulb, cerebral cortex, and hippocampus regions?

Hi,

Thank you for your question. Below is a response from one of our scientific technical experts.

MICrONS does offer detailed synaptic connectivity of tens of thousands of cells, and hundreds of millions of synapses. But all of this is within mouse visual cortex (VISp, VISrl, VISal, VISlm). This data may be well-suited to evaluating the connection weights between cells, depending on your question. Both the binary connection (whether two cells are connected at all) as well as measures of synaptic strength (number of synapses; synapse size) can be extracted with the Connectome Annotation Versioning Engine (CAVE) python package.

We do not have an electron microscopy dataset of other brain regions at this time, and so we do not have the same level of detailed synaptic connectivity in hippocampus or olfactory bulb. If you would like to know more about the MICrONS connectivity data, we can direct you to specific resources.

The MICrONs Tutorial - Synaptic Connectivity is a good option. See also the Connectivity viewer ; and scientific support from the VORTEX project