Functional Connectivity and Selective Odor Responses of Excitatory Local Interneurons in Drosophila Antennal Lobe

• Published in: Neuron (Cambridge, Mass.) Vol. 67; no. 6; pp. 1021 - 1033
• Main Authors: Huang, Ju, Zhang, Wei, Qiao, Wenhui, Hu, Aiqun, Wang, Zuoren
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 23.09.2010; Elsevier Limited
• Subjects: Action Potentials - drug effects; Action Potentials - genetics; Adenosine Triphosphate - pharmacology; Animals; Animals, Genetically Modified; Antennal lobe; Brain; Bungarotoxins - pharmacology; Cholinergic Antagonists - pharmacology; Data analysis; Drosophila; Drosophila Proteins - genetics; Electric Stimulation - methods; Eukaryotic Initiation Factor-5 - genetics; Female; GABA Antagonists - pharmacology; Gap Junctions - drug effects; Gap Junctions - genetics; Gene Expression Regulation - drug effects; Green Fluorescent Proteins - genetics; Inhibitory Postsynaptic Potentials - drug effects; Inhibitory Postsynaptic Potentials - genetics; Insects; Interneurons - drug effects; Interneurons - physiology; Lysine - analogs & derivatives; Lysine - metabolism; Mecamylamine - pharmacology; Nerve Net - cytology; Nerve Net - drug effects; Nerve Net - physiology; Neurons; Nicotinic Antagonists - pharmacology; Odorants; Olfactory Pathways - physiology; Organophosphorus Compounds - pharmacology; Patch-Clamp Techniques; Picrotoxin - pharmacology; Receptors, Purinergic P2 - genetics; Receptors, Purinergic P2 - metabolism; Receptors, Purinergic P2X2; Sense Organs - cytology; Smell - physiology; Studies
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/j.neuron.2010.08.025

Local interneurons in the Drosophila antennal lobe are thought to play important roles in shaping odor responses. However, the physiological properties of excitatory local interneurons (eLNs) and their connectivity in the antennal lobe remain unclear. We first characterized the firing patterns of krasavietz-Gal4-labeled eLNs ( krasavietz eLNs) in response to depolarizing currents. Paired recordings of krasavietz eLNs and PNs showed reciprocal excitatory connections mediated by dendrodendritic cholinergic synapses and gap junctions. Reciprocal connections were also found between two krasavietz eLNs but were rare between krasavietz eLNs and inhibitory LNs. Analysis of response onset latencies showed that krasavietz eLNs received monosynaptic inputs from ORNs. Furthermore, each eLN responded with distinct patterns to different odors, and each odor elicited distinct responses in different eLNs, with specific temporal patterns of spiking, indicating that eLNs serve specific coding functions in addition to global excitation in Drosophila olfactory processing. ► Reciprocal excitatory connections between krasavietz eLNs and PNs ► Cholinergic synapses and gap junctions mediate reciprocal excitation ► Monosynaptic connections from ORNs to krasavietz eLNs ► Selective odor-elicited responses in krasavietz eLNs