Figure 1: Piriform genes and connections segregate into distinct cortical layers.
From: Molecular signatures of neural connectivity in the olfactory cortex
(a) Piriform layers: neurons are sparse in layer I, dense in layer II, and of intermediate density in layer III. (b–d) Immunohistochemical detection (in red) of proteins differentially expressed across piriform layers. (b) Reelin marks densely packed neurons in layer IIa. (c) Cux1 is expressed in neurons of layers IIb and III. (d) Barhl1 marks subpopulations of neurons in layer III. Neurotrace counterstain in blue. (e–h) Schematic representations of the cholera toxin B (CTB) injection sites, and coronal sections through the piriform cortex. CTB labelling in green, Neurotrace counterstain in blue. (e) Neurons projecting to the olfactory bulb (OB) are present in large numbers in layers IIb and III, while (f) neurons projecting to infralimbic division of the medial prefrontal cortex (IL-mPFC) are predominantly located in layer IIb. (g,h) Neurons projecting to the posteriormedial cortical amygdaloid nucleus (CoA) and the lateral entorhinal cortex (lENT) are enriched in layer IIa. Scale bars, 100 μm. Differential distributions of cells are quantified in histograms, data are represented as mean ±s.d. n=number of mice.
