Label-free Imaging of Neurotransmitter Acetylcholine at Neuromuscular Junctions with Stimulated Raman Scattering

Acetylcholine is an important neurotransmitter that relays neural excitation from lower motor neurons to muscles. It also plays significant roles in the central nervous system by modulating neurotransmission. However, there is a lack of tools to directly measure the quantity and distribution of acetylcholine at the subcellular level. In this Communication, we demonstrate for the first time that label-free imaging of acetylcholine is achieved with frequency-modulated spectral-focusing stimulated Raman scattering (FMSF-SRS) microscopy: a technical improvement over traditional SRS microscopy that effectively removes imaging backgrounds. Moreover, we directly quantified the local concentration of acetylcholine at the neuromuscular junction of frog <i>cutaneous pectoris</i> muscle

Visualization 1: Simultaneous two-color stimulated Raman scattering microscopy by adding a fiber amplifier to a 2 ps OPO-based SRS microscope

Epi-SRS in vivo mouse skin imaging. Originally published in Optics Letters on 01 February 2017 (ol-42-3-523

Interfacial Polarity Modulation of KTa_0.5Nb_0.5O₃ Nanoparticles and Its Effect on Dielectric Loss and Breakdown Strength of Poly(vinylidene fluoride) Nanocomposites with High Permittivity

The effects of the morphology, interface, and dielectric constant of inorganic fillers on the dielectric properties of nanocomposites were systemically studied in this paper. It is found that two kinds of KTa_0.5Nb_0.5O₃ (KTN) nanoparticles, synthesized via solid-state reaction and hydrothermal method respectively, can bring different influences on the structure and electrical performance of the KTN/PVDF composites. This is caused by the OH groups on the surface of the H-KTN nanoparticles which were generated through the hydrothermal method. Theoretical models, including the Maxwell–Garnett model, logarithmic model, Jayasundere–Smith model, effective medium theory model, and Weibull distribution method, are employed to explain the dielectric behavior of the composite. Through the comparison between the experimental data and theoretical models, it is concluded that the geometric shape of fillers plays a more crucial role than the dielectric constant of fillers in enhancing the dielectric constant of KTN/PVDF composite films. Consequently, it is an effective way to fabricate the composites with excellent dielectric properties by modulating the geometric shape of inorganic fillers

Details of SSR markers used to map the lm3 locus.

<p>Details of SSR markers used to map the lm3 locus.</p

Details of the putative defense genes and primer sequences used for RT-PCR.

<p>Details of the putative defense genes and primer sequences used for RT-PCR.</p

Chlorophyll content and ratio in the leaves of 3–1, lm3 and their F₁ progeny.

<p><b>a</b> Chl a, Chl b and total Chl content in 3–1, lm3 and their F₁ plants. <b>b</b> Ratio of Chl a to Chl b in 3–1, lm3 and their F₁ plants. The means and SD (standard deviation) are shown with statistical analysis. Chl, chlorophyll; Chl a, chlorophyll <i>a</i>; Chl b, chlorophyll <i>b</i>; FW, fresh weight.</p

Genetic map of the region surrounding <i>lm3</i> on chromosome 3B.

<p><b>a</b> Map constructed using the DNAs from 190 individual F₂ plants from a cross between lm3 and Jingdong8. <b>b</b> Detailed map of <i>lm3</i> on chromosome 3B developed using the derived segregating population from the lm3/Jingdong8 cross, and the genome sequence of Chinese Spring. a and b are not in the same portrait.</p

Transcript abundance of defense-related genes during lesion formation.

<p>Transcript abundance was determined via RT-qPCR, in samples of the roots (no lesions), the 1^st leaves (fully developed lesions), and the 3^rd leaves (developing lesions) of lm3 plants and corresponding tissues of 3–1 plants, and the fold-changes, corresponding to the relative expression of defense-related genes are shown on the <i>y</i>-axis, based on normalization of the expression data for lm3 to 3–1. The <i>error bars</i> represent the standard deviation between biological replicates. Mean fold-changes in the transcript abundance calculated using the △△<i>C</i>t method between biological replicates ± standard deviation.</p

Phenotype of the lm3 mutant.

<p><b>a</b> Phenotype of the lm3 mutant, the wildtype (3–1) plants and their F₁ progeny at two weeks after anthesis in the field. <b>b</b> Comparison of lesion symptoms in different leaves in the lm3 mutant, the wildtype (3–1) plants and their F₁ progeny. For each line, the top fourth, top third, top second and flag leaves are presented from left to right. <b>c</b> Lesion symptoms on the leaf sheath of the lm3 mutant, and wildtype (3–1). <b>d-g</b> Enhanced resistance to powdery mildew. <b>d</b> Reaction of the lm3 mutant and wildtype (3–1) plant to <i>Blumeria graminis</i> f. sp. <i>tritici</i> (<i>Bgt</i>) under natural infection in the adult plant stage under field conditions in 2009. The flag leaves of lm3 plants were covered with yellow necrotic spots, but no spores of <i>Bgt</i> were visible, while many white and brown powdery mildew spores were present on the wildtype (3–1) plants. <b>e</b> Powdery mildew reaction under natural infection at the adult plant stage in the greenhouse in 2015. Only two instances of <i>Bgt</i> sporulation were observed on the older leaves of lm3 plants (yellow arrows), but many white powdery mildew spores were visible on the wildtype (3–1) plants. <b>f</b> and <b>g</b> Responses of the lm3 mutant and wildtype (3–1) plants to <i>Bgt</i> E18 in the growth chamber at the adult stage in 2015. Many white and brown spores of <i>Bgt</i> were observed on the flag leaves (<b>f</b>, <i>right</i>) and top second leaves (<b>g</b>, <i>right</i>) leaves of wildtype (3–1) plants, whereas only one spore (yellow arrows) was present on each of the corresponding leaves of the lm3 mutant (<b>f</b> and <b>g</b>, <i>left</i>), where necrotic spots were widely distributed. All the visible brown spots on lm3 leaves and sheath are necrotic lesions, except a few spores of <i>Bgt</i> indicated by yellow arrows on lm3 leaves (<b>e</b>, <b>f</b> and <b>g</b>), while most visible whitish spots on the leaves of wildtype (3–1) plants are spores of <i>Bgt</i> on the panels (<b>d</b>, <b>e</b>, <b>f</b> and <b>g</b>).</p

Segregation analysis of the LM symptoms in three segregating populations in 2007.

<p>Segregation analysis of the LM symptoms in three segregating populations in 2007.</p