@article {69525, title = {iTome Volumetric Serial Sectioning Apparatus for TEM}, journal = {bioRxiv}, year = {2024}, month = {2024 Jul 07}, abstract = {

An automated ultra-microtome capable of sectioning thousands of ultrathin sections onto standard TEM slot grids was developed and used to section: a complete Drosophila melanogaster first-instar larva, three sections per grid, into 4,866 34-nm-thick sections with a cutting and pickup success rate of 99.74\%; 30 microns of mouse cortex measuring roughly 400 um x 2000 um at 40 nm per slice; and a full adult Drosophila brain and ventral nerve column into 9,300 sections with a pickup success rate of 99.95\%. The apparatus uses optical interferometers to monitor a reference distance between the cutting knife and multiple sample blocks. Cut sections are picked up from the knife-boat water surface while they are still anchored to the cutting knife. Blocks without embedded tissue are used to displace tissue-containing sections away from the knife edge so that the tissue regions end up in the grid slot instead of on the grid rim.

}, doi = {10.1101/2024.07.02.601671}, url = {https://doi.org/10.1101/2024.07.02.601671 }, author = {Peale, David R. and Hess, Harald and Lee, P. R. and Cardona, Albert and Bock, Davi D. and Schneider-Mizell, Casey and Fetter, Richard D. and Lee, Wei-Ping and Robinson, Camenzind G. and Iyer, Nirmala and Managan, Claire} } @article {65314, title = {Input connectivity reveals additional heterogeneity of dopaminergic reinforcement in Drosophila}, journal = {Current Biology}, volume = {30}, year = {2020}, month = {2020 Aug 17}, pages = {3200-11}, abstract = {

Different types of\ Drosophila\ dopaminergic neurons (DANs) reinforce memories of unique valence and provide state-dependent motivational control [1]. Prior studies suggest that the compartment architecture of the mushroom body (MB) is the relevant resolution for distinct DAN functions [2,\ 3]. Here we used a recent electron microscope volume of the fly brain [4] to reconstruct the fine anatomy of individual DANs within three MB compartments. We find the 20 DANs of the γ5 compartment, at least some of which provide reward teaching signals, can be clustered into 5 anatomical subtypes that innervate different regions within γ5. Reconstructing 821 upstream neurons reveals input selectivity, supporting the functional relevance of DAN sub-classification. Only one PAM-γ5 DAN subtype (γ5fb) receives direct recurrent input from γ5β{\textquoteright}2a mushroom body output neurons (MBONs) and behavioral experiments distinguish a role for these DANs in memory revaluation from those reinforcing sugar memory. Other DAN subtypes receive major, and potentially reinforcing, inputs from putative gustatory interneurons or lateral horn neurons, which can also relay indirect feedback from the MB. We similarly reconstructed the single aversively reinforcing PPL1-γ1pedc DAN. The γ1pedc DAN inputs are mostly different to those of γ5 DANs and are clustered onto distinct branches of its dendritic tree, presumably separating its established roles in aversive reinforcement and appetitive motivation [5,\ 6]. Additional tracing identified neurons that provide broad input to γ5, β{\textquoteright}2a and γ1pedc DANs suggesting that distributed DAN populations can be coordinately regulated. These connectomic and behavioral analyses therefore reveal additional complexity of dopaminergic reinforcement circuits between and within MB compartments.

}, author = {Otto, Nils and Pleijzier, Markus W. and Morgan, Isabel C. and Edmondson-Stait, Amelia J and Heinz, Konrad J. and Stark, Ildiko and Dempsey, Georgia and Ito, Masayoshi and Kapoor, Ishaan and Hsu, Joseph and Schlegel, Philipp M. and Bates, Alexander S. and Costa, Marta and Ito, Kei and Bock, Davi D. and Rubin, Gerald M. and Jefferis, Gregory S.X.E. and Waddell, Scott} }