Inhibition is fundamental to information processing by neural circuits. In the olfactory bulb (OB), glomeruli are the functional units for odor information coding, but inhibition among glomeruli is poorly characterized. We used two-photon calcium imaging in anesthetized and awake mice to visualize both odorant-evoked excitation and suppression in OB output neurons (mitral and tufted, MT cells)....

In the olfactory bulb (OB) a sophisticated neuronal network mediates the primary processing of sensory information and extensive investigations over the past decades have greatly improved our understanding of the morphology and neuronal organization of the OB. However, efforts have mostly been focused on the different radial layers, typical for the OB and little attention has been paid to indiv...

TNF is an important mediator of glomerulonephritis. The two TNF-receptors TNFR1 and TNFR2 contribute differently to glomerular inflammation in vivo, but specific mechanisms of TNFR-mediated inflammatory responses in glomeruli are unknown. We investigated their expression and function in murine kidneys, isolated glomeruli ex vivo, and glomerular cells in vitro. In normal kidney TNFR1 and TNFR2 w...

The consensus view of olfactory processing is that the axons of receptor-specific primary olfactory sensory neurons (OSNs) converge to a small subset of glomeruli, thus preserving the odour identity before the olfactory information is processed in higher brain centres. In the present study, we show that two different subsets of ciliated OSNs with different odorant specificities converge to the ...

In many species, including vertebrates and invertebrates, first-order olfactory neuropils are organized into spherical glomeruli, partially enveloped by glial borders. The effect of this characteristic organization on olfactory information processing is poorly understood. The extracellular concentration of potassium ions ([K(+)]) must rise around olfactory receptor axons in specific glomeruli f...

Odorant receptors in the periphery map precisely onto olfactory glomeruli ("coding channels") in the brain. However, the odor tuning of a glomerulus is not strongly correlated with its spatial position. This raises the question of whether lateral inhibition between glomeruli is specific or nonspecific. Here we show that, in the Drosophila brain, focal activation of even a single glomerulus recr...

Arginase shares a common substrate, l-arginine, with nitric oxide synthase (NOS). Both enzymes are active at inflammatory sites. To understand regulation of arginase and its relationship to nitric oxide (NO) production, we studied effects of N G-hydroxy-l-arginine (HOArg) and interleukin-4 (IL-4) on urea and[Formula: see text] synthesis by glomeruli during rat immune glomerulonephritis and comp...

Increases in glomerular size occur with normal body growth and in many pathologic conditions. In this study, we determined associations between glomerular size and numbers of glomerular resident cells, with a particular focus on podocytes. Kidneys from 16 male Caucasian-Americans without overt renal disease, including 4 children (≤3 years old) to define baseline values of early life and 12 adul...

Number of sclerotic glomeruli increases during the aging process. Consequently, majority of remained nonsclerosed glomeruli become hypertrophic and some of them sclerotic, too. The aim of this study was to quantify the size and connective tissue content of nonsclerosed glomeruli and to evaluate the percentage of hypertrophic ones in examined human cases during the aging. Material was right kidn...

Newborn mice rely on olfactory information for survival, but the nature of odor representation in the neonatal olfactory bulb is not well understood. I compared the spatial pattern of odor-evoked responses in 1 to 11 week old mice by imaging the dorsal surface of olfactory bulbs. By using a large panel (~100) of chemically diverse odorants I was able to assign functional tags to individual glom...