Complete Connectomic Reconstruction of Olfactory Projection Neurons in the Fly Brain.
Curr Biol
; 30(16): 3183-3199.e6, 2020 08 17.
Article
en En
| MEDLINE
| ID: mdl-32619485
Nervous systems contain sensory neurons, local neurons, projection neurons, and motor neurons. To understand how these building blocks form whole circuits, we must distil these broad classes into neuronal cell types and describe their network connectivity. Using an electron micrograph dataset for an entire Drosophila melanogaster brain, we reconstruct the first complete inventory of olfactory projections connecting the antennal lobe, the insect analog of the mammalian olfactory bulb, to higher-order brain regions in an adult animal brain. We then connect this inventory to extant data in the literature, providing synaptic-resolution "holotypes" both for heavily investigated and previously unknown cell types. Projection neurons are approximately twice as numerous as reported by light level studies; cell types are stereotyped, but not identical, in cell and synapse numbers between brain hemispheres. The lateral horn, the insect analog of the mammalian cortical amygdala, is the main target for this olfactory information and has been shown to guide innate behavior. Here, we find new connectivity motifs, including axo-axonic connectivity between projection neurons, feedback, and lateral inhibition of these axons by a large population of neurons, and the convergence of different inputs, including non-olfactory inputs and memory-related feedback onto third-order olfactory neurons. These features are less prominent in the mushroom body calyx, the insect analog of the mammalian piriform cortex and a center for associative memory. Our work provides a complete neuroanatomical platform for future studies of the adult Drosophila olfactory system.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Vías Olfatorias
/
Sinapsis
/
Cuerpos Pedunculados
/
Drosophila melanogaster
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Conectoma
/
Interneuronas
/
Neuronas
Límite:
Animals
Idioma:
En
Revista:
Curr Biol
Asunto de la revista:
BIOLOGIA
Año:
2020
Tipo del documento:
Article
Pais de publicación:
Reino Unido