title: Exploring miniature insect brains using micro-CT scanning techniques.
abstract: The capacity to explore soft tissue structures in detail is important in understanding animal physiology and how this determines features such as movement, behaviour and the impact of trauma on regular function. Here we use advances in micro-computed tomography (micro-CT) technology to explore the brain of an important insect pollinator and model organism, the bumblebee (Bombus terrestris). Here we present a method for accurate imaging and exploration of insect brains that keeps brain tissue free from trauma and in its natural stereo-geometry, and showcase our 3D reconstructions and analyses of 19 individual brains at high resolution. Development of this protocol allows relatively rapid and cost effective brain reconstructions, making it an accessible methodology to the wider scientific community. The protocol describes the necessary steps for sample preparation, tissue staining, micro-CT scanning and 3D reconstruction, followed by a method for image analysis using the freeware SPIERS. These image analysis methods describe how to virtually extract key composite structures from the insect brain, and we demonstrate the application and precision of this method by calculating structural volumes and investigating the allometric relationships between bumblebee brain structures.
authors.affiliation: Department of Life Sciences, Imperial College London, Silwood Park, Buckhurst Road, Ascot, Berkshire, SL5 7PY, UK.|School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK.
authors.forename: Dylan B
authors.initials: DB
authors.lastname: Smith
authors.affiliation: Department of Surgery &Cancer, Imperial College London, MSk Laboratory, London, W6 8RP, UK.|Mechatronics, School of Engineering, FHNW, Gründenstrasse 40, 4132 Muttenz, Switzerland.
authors.forename: Galina
authors.initials: G
authors.lastname: Bernhardt
authors.affiliation: School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK.|School of Environmental Sciences, University of Guelph, Guelph, Ontario, N1G 2W1, Canada.
authors.forename: Nigel E
authors.initials: NE
authors.lastname: Raine
authors.affiliation: Department of Surgery &Cancer, Imperial College London, MSk Laboratory, London, W6 8RP, UK.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Abel
authors.affiliation: Core Research Laboratories, Natural History Museum, Cromwell Road, London, SW7 5BD, UK.
authors.forename: Dan
authors.initials: D
authors.lastname: Sykes
authors.affiliation: Core Research Laboratories, Natural History Museum, Cromwell Road, London, SW7 5BD, UK.
authors.forename: Farah
authors.initials: F
authors.lastname: Ahmed
authors.affiliation: School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK.|Bio-Computing &Applied Genetics Division, Centre for Systems Biotechnology, Fraunhofer Chile Research Foundation, Avenida M. Sánchez Fontecilla 310, 7550296, Chile.
authors.forename: Inti
authors.initials: I
authors.lastname: Pedroso
authors.affiliation: Department of Life Sciences, Imperial College London, Silwood Park, Buckhurst Road, Ascot, Berkshire, SL5 7PY, UK.|School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Gill
mesh_terms: D000818:Animals; D001516:Bees / Q000033:anatomy & histology; D049628:Body Size; D001921:Brain / Q000000981:diagnostic imaging*; D005260:Female; D021621:Imaging, Three-Dimensional; D008297:Male; D009929:Organ Size; D055114:X-Ray Microtomography