@article {69710, title = {Discovery of neuronal cell types by pairing whole cell reconstructions with RNA expression profiles}, journal = {bioRxiv}, year = {2024}, month = {12/2024}, abstract = {

Effective classification of neuronal cell types requires both molecular and morphological descriptors to be collected in situ at single cell resolution. However, current spatial transcriptomics techniques are not compatible with imaging workflows that successfully reconstruct the morphology of complete axonal projections. Here, we introduce a new methodology that combines tissue clearing, submicron whole-brain two photon imaging, and Expansion-Assisted Iterative Fluorescence In Situ Hybridization (EASI-FISH) to assign molecular identities to fully reconstructed neurons in the mouse brain, which we call morphoFISH. We used morphoFISH to molecularly identify a previously unknown population of cingulate neurons projecting ipsilaterally to the dorsal striatum and contralaterally to higher-order thalamus. By pairing whole-brain morphometry, improved techniques for nucleic acid preservation and spatial gene expression, morphoFISH offers a quantitative solution for discovery of multimodal cell types and complements existing techniques for characterization of increasingly fine-grained cellular heterogeneity in brain circuits.Competing Interest StatementThe authors have declared no competing interest.

}, doi = {10.1101/2024.12.30.630829}, url = {https://www.biorxiv.org/content/early/2024/12/31/2024.12.30.630829}, author = {The MouseLight Project Team and Ferreira, Tiago A. and Eddison, Mark and Copeland, Monique and Lay, Mary and Tenshaw, Emily and Weldon, Monet and Schauder, David and Olbris, Donald J. and Rokicki, Konrad and Spruston, Nelson and Tillberg, Paul W. and Korff, Wyatt and Dudman, Joshua T.} } @article {65584, title = {A Sparse, Spatially Biased Subtype of Mature Granule Cell Dominates Recruitment in Hippocampal-Associated Behaviors.}, journal = {Cell Reports}, volume = {31}, year = {2020}, month = {2020 Apr 28}, pages = {107551}, abstract = {

Animals can store information about experiences by activating specific neuronal populations, and subsequent reactivation of these neural ensembles can lead to recall of salient experiences. In the hippocampus, granule cells of the dentate gyrus participate in such memory engrams; however, whether there is an underlying logic to granule cell participation has not been examined. Here, we find that a range of novel experiences preferentially activates granule cells of the suprapyramidal blade relative to the infrapyramidal blade. Motivated by this, we identify a suprapyramidal-blade-enriched population of granule cells with distinct spatial, morphological, physiological, and developmental properties. Via transcriptomics, we map these traits onto a sparse and discrete granule cell subtype that is recruited at a 10-fold greater frequency than expected by subtype prevalence, constituting the majority of all recruited granule cells. Thus, in behaviors known to involve hippocampal-dependent memory formation, a rare and spatially localized subtype dominates overall granule cell recruitment.

}, issn = {2211-1247}, doi = {10.1016/j.celrep.2020.107551}, author = {Erwin, Sarah R and Sun, Weinan and Copeland, Monique and Lindo, Sarah and Spruston, Nelson and Cembrowski, Mark S} } @article {49492, title = {The subiculum is a patchwork of discrete subregions.}, journal = {eLife}, volume = {7}, year = {2018}, month = {2018 Oct 30}, abstract = {

In the hippocampus, the classical pyramidal cell type of the subiculum acts as a primary output, conveying hippocampal signals to a diverse suite of downstream regions. Accumulating evidence suggests that the subiculum pyramidal cell population may actually be comprised of discrete subclasses. Here, we investigated the extent and organizational principles governing pyramidal cell heterogeneity throughout the mouse subiculum. Using single-cell RNA-seq, we find that the subiculum pyramidal cell population can be deconstructed into eight separable subclasses. These subclasses were mapped onto abutting spatial domains, ultimately producing a complex laminar and columnar organization with heterogeneity across classical dorsal-ventral, proximal-distal, and superficial-deep axes. We further show that these transcriptomically defined subclasses correspond to differential protein products and can be associated with specific projection targets. This work deconstructs the complex landscape of subiculum pyramidal cells into spatially segregated subclasses that may be observed, controlled, and interpreted in future experiments.

}, issn = {2050-084X}, doi = {10.7554/eLife.37701}, author = {Cembrowski, Mark S and Wang, Lihua and Lemire, Andrew L and Copeland, Monique and DiLisio, Salvatore F and Clements, Jody and Spruston, Nelson} }