scholarly journals Distinct protocerebral neuropils associated with attractive and aversive female-produced odorants in the male moth brain

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Jonas Hansen Kymre ◽  
XiaoLan Liu ◽  
Elena Ian ◽  
Christoffer Nerland Berge ◽  
GuiRong Wang ◽  
...  
Keyword(s):  
Spatial Separation ◽  
Dual Function ◽  
Projection Neurons ◽  
Minor Components ◽  
Wide Spread ◽  
Optimal Model ◽  
Pheromone System ◽  
Heliothine Moths ◽  
Male Specific ◽  
Lateral Protocerebrum

The pheromone system of heliothine moths is an optimal model for studying principles underlying higher-order olfactory processing. In Helicoverpa armigera, three male-specific glomeruli receive input about three female-produced signals, the primary pheromone component, serving as an attractant, and two minor constituents, serving a dual function, i.e. attraction versus inhibition of attraction. From the antennal-lobe glomeruli, the information is conveyed to higher olfactory centers, including the lateral protocerebrum, via three main paths – of which the medial tract is the most prominent. In this study, we traced physiologically identified medial-tract projection neurons from each of the three male‑specific glomeruli with the aim of mapping their terminal branches in the lateral protocerebrum. Our data suggest that the neurons’ wide-spread projections are organized according to behavioral significance, including a spatial separation of signals representing attraction versus inhibition – however, with a unique capacity of switching behavioral consequence based on the amount of the minor components.

scholarly journals Distinct protocerebral neuropils associated with attractive and aversive female-produced odorants in the male moth brain

2020 ◽  
Author(s):  
Jonas Hansen Kymre ◽  
XiaoLan Liu ◽  
Elena Ian ◽  
Christoffer Nerland Berge ◽  
XinCheng Zhao ◽  
...  
Keyword(s):  
Spatial Separation ◽  
Dual Function ◽  
Projection Neurons ◽  
Minor Components ◽  
Wide Spread ◽  
Optimal Model ◽  
Pheromone System ◽  
Heliothine Moths ◽  
Male Specific ◽  
Lateral Protocerebrum

The pheromone system of heliothine moths is an optimal model for studying principles underlying higher-order olfactory processing. In Helicoverpa armigera, three male-specific glomeruli receive input about three female-produced signals, the primary pheromone component, serving as an attractant, and two minor constituents, serving a dual function, i.e. attraction versus inhibition of attraction. From the antennal-lobe glomeruli, the information is conveyed to higher olfactory centers, including the lateral protocerebrum, via three main paths - of which the medial tract is the most prominent. In this study, we traced physiologically identified medial-tract projection neurons from each of the three male specific glomeruli with the aim of mapping their terminal branches in the lateral protocerebrum. Our data suggest that the neurons' wide-spread projections are organized according to behavioral significance, including a spatial separation of signals representing attraction versus inhibition - however, with a unique capacity of switching behavioral consequence based on the amount of the minor components.

scholarly journals A novel major output target for pheromone-sensitive projection neurons in male moths

2019 ◽  
Author(s):  
Xi Chu ◽  
Stanley Heinze ◽  
Elena Ian ◽  
Bente G. Berg
Keyword(s):  
Small Region ◽  
Projection Neurons ◽  
Signal Identification ◽  
Odor Quality ◽  
Plant Odors ◽  
Physiological Properties ◽  
Output Neurons ◽  
Male Specific ◽  
Fast Control ◽  
Lateral Tract

AbstractThe male-specific macroglomerular complex (MGC) in the moth antennal lobe contains circuitry dedicated to pheromone processing. Output neurons from this region project along three parallel pathways, the medial, mediolateral, and lateral tracts. The MGC-neurons of the lateral tract are least described and their functional significance is unknown. We used mass-staining, calcium imaging, and intracellular recording/staining to characterize the morphological and physiological properties of these neurons in Helicoverpa armigera. All lateral-tract MGC neurons targeted the column, a small region within the superior intermediate neuropil. We identified this region as the major converging site for lateral-tract neurons responsive to pheromones and plant-odors. The lateral-tract MGC-neurons consistently responded with a faster onset than the well-described medial-tract neurons. Different from the medial-tract MGC neurons encoding odor quality important for signal identification, those in the lateral tract seem to convey a robust and rapid, but fixed signal – potentially important for fast control of hard-wired behavior.

Convergence of Multimodal Sensory Input Onto Higher-Level Neurons of the Crayfish Olfactory Pathway

2000 ◽  
Vol 84 (6) ◽  
pp. 3043-3055 ◽  
Author(s):  
DeForest Mellon
Keyword(s):  
Compound Eye ◽  
Sensory Information ◽  
Afferent Input ◽  
Oscillatory Activity ◽  
Projection Neurons ◽  
Olfactory Lobe ◽  
Olfactory Pathway ◽  
Accessory Lobe ◽  
Lateral Protocerebrum ◽  
Stimulation Of

Intracellular electrophysiological studies of lateral protocerebral interneurons (LPIs) in the crayfish Procambarus clarkii have revealed convergence of multimodal sensory information onto these higher-level cells of the crustacean central olfactory pathway. Antennular stimulation by odors or electrical shocks generates excitatory-inhibitory sequences in some LPIs as does electrical or hydrodynamic stimulation of the antennae. Photic stimulation of the ipsilateral compound eye generates excitatory responses in LPIs, usually in the form of trains of impulse bursts that are timed to the peaks of the spontaneous oscillatory activity that characterizes these neurons. Focal electrical stimulation of the olfactory lobe, the termination point of antennular afferent input, or the accessory lobe, where higher-level visual and tactile inputs converge, also generates brief excitation and a delayed, prolonged inhibition in LPIs. Both phases of this activity are thought to be transmitted to the lateral protocerebrum via deutocerebral projection neurons, which have extensive dendritic arborizations in the olfactory lobe and the accessory lobe. The excitatory pathway is thought to synapse directly with target LPIs, whereas the inhibitory pathway is probably indirect and mediated through GABAergic interneurons within the lateral protocerebrum. There is evidence that both presynaptic and postsynaptic inhibition suppress activity in LPIs. Preliminary observations suggest that a small cluster of neurons adjacent to the hemi-ellipsoid body are inhibitory to LPI activity. Multimodal inhibitory and excitatory modulation of LPI activity may play a part in the contextual identification of odors in the crayfish olfactory system.

Monoterpenoid signals and their transcriptional responses to feeding and juvenile hormone regulations in bark beetle Ips hauseri Reitter

2021 ◽  
Author(s):  
Jia Xing Fang ◽  
Hui Cong Du ◽  
Xia Shi ◽  
Su Fang Zhang ◽  
Fu Liu ◽  
...  
Keyword(s):  
Juvenile Hormone ◽  
Interspecific Interactions ◽  
Transcriptional Responses ◽  
Feeding Behaviors ◽  
Expression Of Genes ◽  
Feeding Stimulation ◽  
Signal Production ◽  
Pheromone System ◽  
Species Specific ◽  
Male Specific

Hauser's engraver beetle Ips hauseri Reitter is a serious pest in spruce forest ecosystems in Central Asia. Its monoterpenoid signal production, transcriptome responses, and potential regulatory mechanisms remain poorly understood. The quality and quantity of volatile metabolites in hindgut extracts of I. hauseri were found to differ between males and females and among three groups: beetles that are newly emerged, those with a topical application of juvenile hormone III (JHIII), and those that have been feeding for 24 h. Feeding males definitively dominate monoterpenoid signal production in I. hauseri, which uses (4S)-(–)-ipsenol and (S)-(–)-cis-verbenol to implement reproductive segregation from I. typographus and I. shangrila. Feeding stimulation can induce higher expression of most genes related to the biosynthesis of (4S)-(–)-ipsenol than JHIII induction, and it shows a male-specific mode in I. hauseri. JHIII can stimulate males to produce large amounts of (–)-verbenone and also upregulates a higher expression of several CYP6 genes in males than females. The expression of genes involved in the metabolism of JHIII in females and males were found to be upregulated. A species-specific aggregation pheromone system for I. hauseri, consisting of (4S)-(–)-ipsenol and S-(–)-cis-verbenol, can be used to monitor population dynamics or mass trap killing. Our results also enable a better understanding of the bottom-up role of feeding behaviors in mediating population reproduction/aggregation and interspecific interactions.

scholarly journals Coherent Oscillations in Membrane Potential Synchronize Impulse Bursts in Central Olfactory Neurons of the Crayfish

1999 ◽  
Vol 81 (3) ◽  
pp. 1231-1241 ◽  
Author(s):  
DeForest Mellon ◽  
Christopher J. Wheeler
Keyword(s):  
Membrane Potential ◽  
Procambarus Clarkii ◽  
Synaptic Activity ◽  
Projection Neurons ◽  
Freshwater Crayfish ◽  
Olfactory Pathway ◽  
Olfactory Neurons ◽  
Baseline Activity ◽  
The Common ◽  
Lateral Protocerebrum

Coherent oscillations in membrane potential synchronize impulse bursts in central olfactory neurons of the crayfish. Lateral protocerebral interneurons (LPIs) in the central olfactory pathway of the freshwater crayfish Procambarus clarkii reside within the lateral protocerebrum and receive direct input from projection neurons of the olfactory midbrain. The LPIs exhibit periodic (0.5 Hz) changes in membrane potential that are imposed on them synaptically. Acute surgical experiments indicate that the synaptic activity originates from a group of oscillatory neurons lying within the lateral protocerebrum. Simultaneous intracellular recordings from many LPI pairs indicate that this periodic synaptic input is synchronous and coherent among the population of ∼200 LPIs on each side of the brain. In many LPIs, specific odors applied to antennules in isolated head preparations generate long-lasting excitatory postsynaptic potentials and impulse bursts. The impulse bursts are generated only near the peaks of the ongoing depolarizations, ∼1 s after stimulus application, and so the periodic baseline activity is instrumental in timing burst generation. Simultaneous recordings from pairs of LPIs show that, when impulse bursts occur in both cells after an odorant stimulus, they are synchronized by the common periodic depolarizations. We conclude that the common, periodic activity in LPIs can synchronize impulse bursts in subsets of these neurons, possibly generating powerful long-lasting postsynaptic effects in downstream target neurons.

scholarly journals Morphology and physiology of olfactory neurons in the lateral protocerebrum of the silkmoth Bombyx mori

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shigehiro Namiki ◽  
Ryohei Kanzaki
Keyword(s):  
Bombyx Mori ◽  
Projection Neurons ◽  
Suitable Model ◽  
Olfactory Neurons ◽  
Delta Area ◽  
Output Neurons ◽  
Plant Odours ◽  
Mushroom Body Calyx ◽  
The Brain ◽  
Lateral Protocerebrum

Abstract Insect olfaction is a suitable model to investigate sensory processing in the brain. Olfactory information is first processed in the antennal lobe and is then conveyed to two second-order centres—the mushroom body calyx and the lateral protocerebrum. Projection neurons processing sex pheromones and plant odours supply the delta area of the inferior lateral protocerebrum (∆ILPC) and lateral horn (LH), respectively. Here, we investigated the neurons arising from these regions in the brain of the silkmoth, Bombyx mori, using mass staining and intracellular recording with a sharp glass microelectrode. The output neurons from the ∆ILPC projected to the superior medial protocerebrum, whereas those from the LH projected to the superior lateral protocerebrum. The dendritic innervations of output neurons from the ∆ILPC formed a subdivision in the ∆ILPC. We discuss pathways for odour processing in higher order centres.

scholarly journals Long-range projection neurons in the taste circuit of Drosophila

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Heesoo Kim ◽  
Colleen Kirkhart ◽  
Kristin Scott
Keyword(s):  
Mushroom Body ◽  
Conditioned Aversion ◽  
Projection Neurons ◽  
Neural Pathways ◽  
Learning Centers ◽  
Feeding Behaviors ◽  
Learned Behavior ◽  
Learned Behaviors ◽  
Receptor Neurons ◽  
Lateral Protocerebrum

Taste compounds elicit innate feeding behaviors and act as rewards or punishments to entrain other cues. The neural pathways by which taste compounds influence innate and learned behaviors have not been resolved. Here, we identify three classes of taste projection neurons (TPNs) in Drosophila melanogaster distinguished by their morphology and taste selectivity. TPNs receive input from gustatory receptor neurons and respond selectively to sweet or bitter stimuli, demonstrating segregated processing of different taste modalities. Activation of TPNs influences innate feeding behavior, whereas inhibition has little effect, suggesting parallel pathways. Moreover, two TPN classes are absolutely required for conditioned taste aversion, a learned behavior. The TPNs essential for conditioned aversion project to the superior lateral protocerebrum (SLP) and convey taste information to mushroom body learning centers. These studies identify taste pathways from sensory detection to higher brain that influence innate behavior and are essential for learned responses to taste compounds.

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