CX naming conventions clarification (PB/FB/EB indexing)

[Dean Pospisil]

Hi neuPrint group,

I am trying to sanity check my understanding of central complex (CX) naming conventions in neuPrint, particularly how they relate to compartment membership. I would appreciate any corrections.

Many columnar CX neurons include suffixes like _L# or _C#, where # ranges from 1–9 or 1–12. My understanding is that these refer to protocerebral bridge (PB) compartments (L/R1–9) and fan-shaped body (FB) columns (C1–C9 or C1–C12), respectively. Is this correct?

For example, for PFL2(PB12b)_L3_C7, my interpretation is:
- (PB12b) specifies a PB compartment, possibly indicating a finer subdivision of PB glomeruli,
- _L3 refers to PB innervation in left glomerulus 3,
- _C7 indicates projections to FB column 7.

Is this interpretation accurate? Also, what does “12b” in PB12b denote. Does it correspond to a specific sub-compartment or labeling scheme within the PB?

For delta7 neurons things are a little different:

Delta7(PB15)_L3R6_R

does L3R6 indicate connectivity to two PB compartments? 

Finally, I have not been able to find clear documentation on how ellipsoid body (EB) wedge angular positions map onto these naming conventions. Is there a standard reference for EB wedge indexing and its relationship to PB or FB coordinates?

Thanks for any guidance.

Best,  
Dean

[Berg, Stuart]

Shinya, can you please clarify the CX naming conventions for Dean?

Thanks,

Stuart

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From: neup...@googlegroups.com <neup...@googlegroups.com> on behalf of Dean Pospisil <dean.abrah...@gmail.com>
Sent: Thursday, March 19, 2026 13:27
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Subject: CX naming conventions clarification (PB/FB/EB indexing)

 

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[Takemura, Shin-ya]

Hi Dean,

Your understanding is mostly correct, but I’d like to clarify one point regarding the names in parentheses.

The names like (PB12b) or (PB15) were temporary identifiers used during the early stages of the project to map our data to previous CX studies.  We kept them in parentheses within the instance for historical reference and convenience.

Therefore, the actual subcompartment and column information (such as _L3 or _C7) is completely independent of the numbers or letters inside those parentheses.  You should rely on the _L#, _R#, and _C# suffixes for the structural indexing.

I hope this clears up the confusion!

Best,

Shinya