Summary
The dorsal raphe nucleus (DRN) in the midbrain is a key center for serotonin (5-hydroxytryptamine; 5-HT) expressing neurons. Serotonergic neurons in the DRN have been theorized to encode punishment by opposing the reward signaling of dopamine neurons. Here, we show that DRN neurons encode reward, but not punishment, through 5-HT and glutamate. Optogenetic stimulation of DRN Pet-1 neurons reinforces mice to explore the stimulation-coupled spatial region, shifts sucrose preference, drives optical self-stimulation, and directs sensory discrimination learning. DRN Pet-1 neurons increase their firing activity during reward tasks and this activation can be used to rapidly change neuronal activity patterns in the cortnassociated with 5-HT, they also release glutamate, and both neurotransmitters contribute to reward signaling. These experiments demonstrate the ability of DRN neurons to organize reward behaviors and might provide insights into the underlying mechanisms of learning facilitation and anhedonia treatment.
Deficiency of citrin, a liver-type mitochondrial aspartate-glutamate carrier (AGC), encoded by the SLC25A13 gene on chromosome 7q21.3, causes autosomal recessive disorders: adult-onset type II citrullinemia (CTLN2) and neonatal hepatitis associated with intrahepatic cholestasis (NICCD). So far, we have described 12 SLC25A13 mutations: 11 were from Japan and one from Israel. Three mutations found in Chinese and Vietnamese patients were the same as those in Japanese patients. In the present study, we identified a novel mutation IVS6+1G>C in a Japanese CTLN2 patient and widely screened 12 SLC25A13 mutations found in Japanese patients in control individuals from East Asia to confirm our preliminary results that the carrier frequency was high in Asian populations. Mutations 851-854del and 1638-1660dup were found in all Asian countries tested, and 851-854del associated with 290-haplotype in microsatellite marker D7S1812 was especially frequent. Other mutations frequently detected were IVS11+1G>A in Japanese and Korean, S225X in Japanese, and IVS6+5G>A in Chinese populations. We found a remarkable difference in carrier rates in China (including Taiwan) between north (1/ 940) and south (1/48) of the Yangtze River. We detected many carriers in Chinese (64/4169 = 1/65), Japanese (20/1372 = 1/69) and Korean (22/2455 = 1/112) populations, suggesting that over 80,000 East Asians are homozygotes with two mutated SLC25A13 alleles.
Olfactory sensory neurons expressing a common receptor gene converge onto one or a few glomeruli with stereotyped positions within the mouse main olfactory bulb (MOB), producing a map of approximately 1800 olfactory columns representing approximately 1000 odorant receptors. Here, we report that this precise olfactory map is maintained over several synapses that ultimately cross MOB hemispheres to link bilateral isofunctional olfactory columns. Focal injection of tracer into genetically identified glomeruli revealed an exquisite topography that involves a bilateral connection via the anterior olfactory nucleus pars externa (AONpE) that links isofunctional olfactory columns in the contralateral MOB. Physiological and behavioral assays revealed an important role for the AONpE in bilateral exchange of odorant-specific information. These results indicate that the interbulbar link through the AONpE integrates bilateral olfactory sensory maps and exchanges olfactory information, positioning it as a unique model system for studying interhemispheric connections.
We present a mechanism for controlling the accumulation and discharge of Al atoms using electromigration, by which long thin Al wires of lengths up to 336 µm and diameters ranging from 0.8 to 4 µm were fabricated. The experimental samples were Al lines formed on a TiN layer and covered with a SiO2 passivation layer. A slit in the Al film and a hole through the oxide or through the oxide and the Al film at the anode end of the line were used to control the accumulation and discharge processes. It was found that the position of the bottom of the hole, which was either at the SiO2/Al or Al/TiN interface, significantly affected these processes. A hole introduced down to the Al/TiN interface prevented cracks from forming in the line by relieving the compressive stress caused by accumulating atoms, and helped to extend the lifetime of the line. Guidelines for effectively controlling the accumulation and discharge of Al atoms were drawn, and based on these guidelines, other Al microstructures requiring the accumulation of a large number of atoms were fabricated after several tens of minutes of current supply.
Carbon supported Pd-Sn nanoparticle electrocatalysts (Pd-Sn/C) are prepared via a facilely and environmental friendly method and successfully applied in BH4− electrooxidation. Transmission electron microscopy results and X-ray diffraction results show...
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