Best practices for reporting brain connectivity

The bibliographic meta data of any peer-reviewed scientific publication is standardized and therefore this information is indexed and searchable. However, a publication's scientific content is unstructured, which too often causes a loss of invaluable knowledge. It alsomakes it more difficult or even impossible to integrate research findings across publications. On this page, the temporal-lobe curators give their view on which information is important when reporting scientific result of tract-tracing/brain connectivity experiments. Although some of these recommendations state the obvious, we have found many publications in which key information is missing.


Reporting methods

Species

The animal model under consideration.

Report these elements

When reporting results in one or more species, always include the following information about your research subjects:

Methods

Reporting methods

Include key information

When reporting experimental methods, include the following information:

  • in case of injection of a substance that allows visualization of neuronal connections
    • specify the delivery method of that substance (e.g. glass pipette, hamilton syringe, etc) including tip diameter.
    • specify which brain atlas was used to define stereotaxic coordinates, specify those coordinates, specify injection angle, other details (e.g. if a guide cannula was used to prevent leakage into other areas).

Reporting results

Experimental results

Your reporting style

Define how you are reporting your results

When reporting results from multiple experiments, include the following information:

  • species (see above)
  • animal / experiment ID
    • In case results are described in an aggregated manner:
      • results can only be lumped together if experiments are performed under exactly the same conditions
      • specify which animal / experiment ID's are grouped together
      • specify the total count of animals / experiments that are described
    • In case results are described based on individual eperiments (i.e. in one animal):
      • specify the animal / experiment ID
      • specify that the results are based on a single animal

Brain connectivity

Your reporting style

Define key aspects of brain connectivity

  • specify which hemisphere the experimental results apply to:
    • tracer injections in the left hemisphere with results described in the left hemisphere are of type LEFT-LEFT (LL)
    • tracer injections in the left hemisphere with results described in the right hemisphere are of type LEFT-RIGHT (LR)
    • tracer injections in the right hemisphere with results described in the right hemisphere are of type RIGHT-RIGHT (RR)
    • tracer injections in the right hemisphere with results described in the left hemisphere are of type RIGHT-LEFT (RL)
    • By only stating that a connection is ipsilateral or contralateral, information loss occurs.
    • By not stating any information about laterality of a connection, information loss occurs.
  • do not only describe positive findings (e.g. I see termination in area A), but also include relevant null findings (I see termination in area A; no label was seen in area B, C). Or terminal labeling was seen in layers IIb, III; no terminal labelling was seen in layers I, IV, V and VI. Without the latter part, the information is incomplete.
  • try to describe the position of the injection and terminal labeling in great detail. When describing results for the hippocampus, mention if you are in the septal, middle or temporal one-thirds of the structure, and in the proximal, mid proximodistal or distal part of the structure. Otherwise information loss occurs.
  • For an example of a table that presents tract tracing results in a clear manner, take a look at Kemppainen et al, 2002.

© Copyright 2007 - 2022 N.L.M. Cappaert & N.M. van Strien. All rights reserved. Content is available under Attribution-Noncommercial-No Derivative Works 3.0 Unported. Currently this work is financially supported by the Dutch Research Council. Project DOI: 10.21942/uva.19786213.v1