Metastatic Gastric Signet Ring Cell Carcinoma Mimicking Crohn's Disease.

Signet-ring cell carcinoma (SRCC) is an adenocarcinoma characterized by mucin-producing cells and most commonly arises in the stomach. Colonic SRCC can share features of colitis, including long segments of concentric bowel wall thickening and ulcerated mucosa with regions of sparing. We describe a rare case of metastatic gastric SRCC mimicking Crohn's disease.

Sensory maps in the olfactory cortex defined by long-range viral tracing of single neurons.

Sensory information may be represented in the brain by stereotyped mapping of axonal inputs or by patterning that varies between individuals. In olfaction, a stereotyped map is evident in the first sensory processing centre, the olfactory bulb (OB), where different odours elicit activity in unique combinatorial patterns of spatially invariant glomeruli. Activation of each glomerulus is relayed to higher cortical processing centres by a set of ∼20-50 'homotypic' mitral and tufted (MT) neurons.