scholarly journals Octopaminergic neurons have multiple targets in Drosophila larval mushroom body calyx and regulate behavioral odor discrimination

2018 ◽  
Author(s):  
J Y Hilary Wong ◽  
Bo Angela Wan ◽  
Tom Bland ◽  
Marcella Montagnese ◽  
Alex McLachlan ◽  
...  
Keyword(s):  
Mushroom Body ◽  
Inhibitory Neuron ◽  
Odor Discrimination ◽  
Learning Ability ◽  
Projection Neurons ◽  
Input Region ◽  
Output Neurons ◽  
Mushroom Body Calyx ◽  
Intrinsic Neurons ◽  
Selection Of

AbstractDiscrimination of sensory signals is essential for an organism to form and retrieve memories of relevance in a given behavioural context. Sensory representations are modified dynamically by changes in behavioral state, facilitating context-dependent selection of behavior, through signals carried by noradrenergic input in mammals, or octopamine (OA) in insects. To understand the circuit mechanisms of this signaling, we characterized the function of two OA neurons, sVUM1 neurons, that originate in the subesophageal zone (SEZ) and target the input region of the memory center, the mushroom body (MB) calyx, in larval Drosophila. We find that sVUM1 neurons target multiple neurons, including olfactory projection neurons (PNs), the inhibitory neuron APL, and a pair of extrinsic output neurons, but relatively few mushroom body intrinsic neurons, Kenyon cells. PN terminals carried the OA receptor Oamb, a Drosophila α1-adrenergic receptor ortholog. Using an odor discrimination learning paradigm, we showed that optogenetic activation of OA neurons compromised discrimination of similar odors but not learning ability. Our results suggest that sVUM1 neurons modify odor representations via multiple extrinsic inputs at the sensory input area to the MB olfactory learning circuit.

scholarly journals Circuit reorganization in the Drosophila mushroom body calyx accompanies memory consolidation

2020 ◽  
Author(s):  
Lothar Baltruschat ◽  
Philipp Ranft ◽  
Luigi Prisco ◽  
J. Scott Lauritzen ◽  
André Fiala ◽  
...  
Keyword(s):  
Conditioned Stimulus ◽  
Memory Consolidation ◽  
Mushroom Body ◽  
Structural Changes ◽  
De Novo ◽  
Projection Neurons ◽  
Structural Modifications ◽  
Behavioural Experiments ◽  
The Individual ◽  
Mushroom Body Calyx

SummaryThe capacity of utilizing past experience to guide future action is a fundamental and conserved function of the nervous system. Associative memory formation initiated by the coincident detection of a conditioned stimulus (CS, e.g. odour) and an unconditioned stimulus (US, e.g. sugar reward) can lead to a short-lived memory trace (STM) within distinct circuits [1-5]. Memories can be consolidated into long-term memories (LTM) through processes that are not fully understood, but depend on de-novo protein synthesis [6, 7], require structural modifications within the involved neuronal circuits and might lead to the recruitment of additional ones [8-17]. Compared to modulation of existing connections, the reorganization of circuits affords the unique possibility of sampling for potential new partners [18-20]. Nonetheless, only few examples of rewiring associated with learning have been established thus far [14, 21-24]. Here, we report that memory consolidation is associated with the structural and functional reorganization of an identified circuit in the adult fly brain. The formation and retrieval of olfactory associative memories in Drosophila requires the mushroom body (MB) [25]. We identified the individual synapses of olfactory projection neurons (PNs) that deliver a conditioned odour to the MB and reconstructed the complexity of the microcircuit they form. Combining behavioural experiments with high-resolution microscopy and functional imaging, we demonstrated that the consolidation of appetitive olfactory memories closely correlates with an increase in the number of synaptic complexes formed by the PNs that deliver the conditioned stimulus and their postsynaptic partners. These structural changes result in additional functional synaptic connections.

Mushroom Body of the Honeybee

2017 ◽  
pp. 353-360
Author(s):  
Jürgen Rybak ◽  
Randolf Menzel
Keyword(s):  
Mushroom Body ◽  
Higher Order ◽  
Insect Species ◽  
Insect Brain ◽  
Projection Neurons ◽  
Kenyon Cells ◽  
Output Neurons ◽  
The Brain

The mushroom body (MB) in the insect brain is composed of a large number of densely packed neurons called Kenyon cells (KCs) (Drosophila, 2200; honeybee, 170,000). In most insect species, the MB consists of two caplike dorsal structures, the calyces, which contain the dendrites of KCs, and two to four lobes formed by collaterals of branching KC axons. Although the MB receives input and provides output throughout its whole structure, the neuropil part of the calyx receives predominantly multimodal input from sensory projection neurons (PNs) of second or a higher order, and the lobes send output neurons to many other parts of the brain, including recurrent neurons to the MB calyx. Widely branching, supposedly modulatory neurons (serotonergic, octopaminergic) innervate the MB at all levels (calyx, peduncle, and lobes), including the somata of KCs in the calyx (dopamine).

Different classes of input and output neurons reveal new features in microglomeruli of the adult Drosophila mushroom body calyx

2012 ◽  
Vol 520 (10) ◽  
pp. 2185-2201 ◽  
Author(s):  
Nancy J. Butcher ◽  
Anja B. Friedrich ◽  
Zhiyuan Lu ◽  
Hiromu Tanimoto ◽  
Ian A. Meinertzhagen
Keyword(s):  
Mushroom Body ◽  
Input And Output ◽  
Output Neurons ◽  
Mushroom Body Calyx ◽  
Adult Drosophila

scholarly journals Convergence of monosynaptic and polysynaptic sensory paths onto common motor outputs in a Drosophila feeding connectome

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Anton Miroschnikow ◽  
Philipp Schlegel ◽  
Andreas Schoofs ◽  
Sebastian Hueckesfeld ◽  
Feng Li ◽  
...  
Keyword(s):  
Food Intake ◽  
Mushroom Body ◽  
Sensory Inputs ◽  
Input And Output ◽  
Drosophila Larvae ◽  
Output Neurons ◽  
Overlapping Domains ◽  
Motor Outputs ◽  
Neuroendocrine Neurons ◽  
Mushroom Body Calyx

We reconstructed, from a whole CNS EM volume, the synaptic map of input and output neurons that underlie food intake behavior of Drosophila larvae. Input neurons originate from enteric, pharyngeal and external sensory organs and converge onto seven distinct sensory synaptic compartments within the CNS. Output neurons consist of feeding motor, serotonergic modulatory and neuroendocrine neurons. Monosynaptic connections from a set of sensory synaptic compartments cover the motor, modulatory and neuroendocrine targets in overlapping domains. Polysynaptic routes are superimposed on top of monosynaptic connections, resulting in divergent sensory paths that converge on common outputs. A completely different set of sensory compartments is connected to the mushroom body calyx. The mushroom body output neurons are connected to interneurons that directly target the feeding output neurons. Our results illustrate a circuit architecture in which monosynaptic and multisynaptic connections from sensory inputs traverse onto output neurons via a series of converging paths.

Targeting expression to projection neurons that innervate specific mushroom body calyx and antennal lobe glomeruli in larval Drosophila

2010 ◽  
Vol 10 (7-8) ◽  
pp. 328-337 ◽  
Author(s):  
Liria M. Masuda-Nakagawa ◽  
Takeshi Awasaki ◽  
Kei Ito ◽  
Cahir J. O’Kane
Keyword(s):  
Mushroom Body ◽  
Antennal Lobe ◽  
Projection Neurons ◽  
Mushroom Body Calyx

Microcircuits of the Striatum

2017 ◽  
pp. 121-132
Author(s):  
Natalie M. Doig ◽  
J. Paul Bolam
Keyword(s):  
Basal Ganglia ◽  
Caudate Nucleus ◽  
Internal Capsule ◽  
Projection Neurons ◽  
Gabaergic Interneurons ◽  
Cholinergic Interneurons ◽  
Spiny Neurons ◽  
Output Neurons ◽  
Major Division ◽  
Selection Of

The striatum (or caudate-putamen, or caudate nucleus and putamen in those species in which they are divided by the internal capsule) is the major division of the basal ganglia, a group of structures involved in a variety of processes, including movement and cognitive and mnemonic functions. The striatum consists of a population of principal neurons, the medium-sized, densely spiny neurons (MSNs)—accounting for up to 97% of all neurons depending on species—which are the projection neurons of the striatum, several populations of GABAergic interneurons, and a population of cholinergic interneurons. The principal afferents of the striatum are glutamatergic, are derived from the cortex and thalamus, and mainly innervate the spines of MSNs. The essential computation performed by the striatum is the decision about which MSNs will fire, the consequence of which is altered firing of basal ganglia output neurons, and hence the selection of the basal ganglia–associated behavior.

scholarly journals Octopaminergic neurons have multiple targets in Drosophila larval mushroom body calyx and can modulate behavioral odor discrimination

2021 ◽  
Vol 28 (2) ◽  
pp. 53-71
Author(s):  
J.Y. Hilary Wong ◽  
Bo Angela Wan ◽  
Tom Bland ◽  
Marcella Montagnese ◽  
Alex D. McLachlan ◽  
...  
Keyword(s):  
Mushroom Body ◽  
Odor Discrimination ◽  
Multiple Targets ◽  
Mushroom Body Calyx

scholarly journals Inhibitory muscarinic acetylcholine receptors enhance aversive olfactory learning in adult Drosophila

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Noa Bielopolski ◽  
Hoger Amin ◽  
Anthi A Apostolopoulou ◽  
Eyal Rozenfeld ◽  
Hadas Lerner ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Mushroom Body ◽  
Acetylcholine Receptors ◽  
Olfactory Learning ◽  
Muscarinic Acetylcholine Receptors ◽  
Projection Neurons ◽  
Kenyon Cell ◽  
Muscarinic Acetylcholine ◽  
Kenyon Cells ◽  
Output Neurons

Olfactory associative learning in Drosophila is mediated by synaptic plasticity between the Kenyon cells of the mushroom body and their output neurons. Both Kenyon cells and their inputs from projection neurons are cholinergic, yet little is known about the physiological function of muscarinic acetylcholine receptors in learning in adult flies. Here, we show that aversive olfactory learning in adult flies requires type A muscarinic acetylcholine receptors (mAChR-A), particularly in the gamma subtype of Kenyon cells. mAChR-A inhibits odor responses and is localized in Kenyon cell dendrites. Moreover, mAChR-A knockdown impairs the learning-associated depression of odor responses in a mushroom body output neuron. Our results suggest that mAChR-A function in Kenyon cell dendrites is required for synaptic plasticity between Kenyon cells and their output 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 The complete connectome of a learning and memory center in an insect brain

2017 ◽  
Author(s):  
Katharina Eichler ◽  
Feng Li ◽  
Ashok Litwin-Kumar ◽  
Youngser Park ◽  
Ingrid Andrade ◽  
...  
Keyword(s):  
Learning And Memory ◽  
Mushroom Body ◽  
Negative Reinforcement ◽  
Insect Brain ◽  
Projection Neurons ◽  
Functional Studies ◽  
Output Neuron ◽  
Kenyon Cells ◽  
Output Neurons ◽  
Complete Circuit

Associating stimuli with positive or negative reinforcement is essential for survival, but a complete wiring diagram of a higherorder circuit supporting associative memory has not been previously available. We reconstructed one such circuit at synaptic resolution, theDrosophilalarval mushroom body, and found that most Kenyon cells integrate random combinations of inputs but a subset receives stereotyped inputs from single projection neurons. This organization maximizes performance of a model output neuron on a stimulus discrimination task. We also report a novel canonical circuit in each mushroom body compartment with previously unidentified connections: reciprocal Kenyon cell to modulatory neuron connections, modulatory neuron to output neuron connections, and a surprisingly high number of recurrent connections between Kenyon cells. Stereotyped connections between output neurons could enhance the selection of learned responses. The complete circuit map of the mushroom body should guide future functional studies of this learning and memory center.

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