Transsynaptic mapping of Drosophila mushroom body output neurons

AbstractThe Mushroom Body (MB) is a well-characterized associative memory structure within the Drosophila brain. Although previous studies have analyzed MB connectivity and provided a map of inputs and outputs, a detailed map of the downstream targets is missing. Using the genetic anterograde transsynaptic tracing tool, trans-Tango, we identified divergent projections across the brain and convergent downstream targets of the MB output neurons (MBONs). Our analysis revealed at least three separate targets that receive convergent input from MBONs: other MBONs, the fan shaped body (FSB), and the lateral accessory lobe (LAL). We describe, both anatomically and functionally, a multilayer circuit in which inhibitory and excitatory MBONs converge on the same genetic subset of FSB and LAL neurons. This circuit architecture provides an opportunity for the brain to update information and integrate it with previous experience before executing appropriate behavioral responses.Highlights-The postsynaptic connections of the output neurons of the mushroom body, a structure that integrates environmental cues with associated valence, are mapped using trans-Tango.-Mushroom body circuits are highly interconnected with several points of convergence among mushroom body output neurons (MBONs).-The postsynaptic partners of MBONs have divergent projections across the brain and convergent projections to select target neuropils outside the mushroom body important for multimodal integration.-Functional connectivity suggests the presence of multisynaptic pathways that have several layers of integration prior to initiation of an output response.

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Transsynaptic mapping of Drosophila mushroom body output neurons

eLife ◽

10.7554/elife.63379 ◽

2021 ◽

Vol 10 ◽

Author(s):

Kristin M Scaplen ◽

Mustafa Talay ◽

John D Fisher ◽

Raphael Cohn ◽

Altar Sorkaç ◽

...

Keyword(s):

Associative Memory ◽

Mushroom Body ◽

Behavioral Responses ◽

Previous Experience ◽

Shaped Body ◽

Functional Implications ◽

Output Neurons ◽

Functional Relevance ◽

The Brain ◽

Lateral Accessory Lobe

The mushroom body (MB) is a well-characterized associative memory structure within the Drosophila brain. Analyzing MB connectivity using multiple approaches is critical for understanding the functional implications of this structure. Using the genetic anterograde transsynaptic tracing tool, trans-Tango, we identified divergent projections across the brain and convergent downstream targets of the MB output neurons (MBONs). Our analysis revealed at least three separate targets that receive convergent input from MBONs: other MBONs, the fan-shaped body (FSB), and the lateral accessory lobe (LAL). We describe, both anatomically and functionally, a multilayer circuit in which inhibitory and excitatory MBONs converge on the same genetic subset of FSB and LAL neurons. This circuit architecture enables the brain to update and integrate information with previous experience before executing appropriate behavioral responses. Our use of trans-Tango provides a genetically accessible anatomical framework for investigating the functional relevance of components within these complex and interconnected circuits.

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Mushroom Body of the Honeybee

Handbook of Brain Microcircuits ◽

10.1093/med/9780190636111.003.0029 ◽

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).

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Faculty Opinions recommendation of Brain structure and functional connectivity associated with pornography consumption: the brain on porn.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.718524746.793498318 ◽

2014 ◽

Author(s):

Bryon Adinoff

Keyword(s):

Functional Connectivity ◽

Brain Structure ◽

Pornography Consumption ◽

The Brain

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The Brain Resting-State Functional Connectivity Underlying Violence Proneness: Is It a Reliable Marker for Neurocriminology? A Systematic Review

Behavioral Sciences ◽

10.3390/bs9010011 ◽

2019 ◽

Vol 9 (1) ◽

pp. 11 ◽

Cited By ~ 4

Author(s):

Ángel Romero-Martínez ◽

Macarena González ◽

Marisol Lila ◽

Enrique Gracia ◽

Luis Martí-Bonmatí ◽

...

Keyword(s):

Functional Connectivity ◽

Effective Treatment ◽

Resting State ◽

Brain Structures ◽

Prevention Programs ◽

Angular Gyrus ◽

Resting State Functional Connectivity ◽

Treatment And Prevention ◽

Reliable Marker ◽

The Brain

Introduction: There is growing scientific interest in understanding the biological mechanisms affecting and/or underlying violent behaviors in order to develop effective treatment and prevention programs. In recent years, neuroscientific research has tried to demonstrate whether the intrinsic activity within the brain at rest in the absence of any external stimulation (resting-state functional connectivity; RSFC) could be employed as a reliable marker for several cognitive abilities and personality traits that are important in behavior regulation, particularly, proneness to violence. Aims: This review aims to highlight the association between the RSFC among specific brain structures and the predisposition to experiencing anger and/or responding to stressful and distressing situations with anger in several populations. Methods: The scientific literature was reviewed following the PRISMA quality criteria for reviews, using the following digital databases: PubMed, PsycINFO, Psicodoc, and Dialnet. Results: The identification of 181 abstracts and retrieval of 34 full texts led to the inclusion of 17 papers. The results described in our study offer a better understanding of the brain networks that might explain the tendency to experience anger. The majority of the studies highlighted that diminished RSFC between the prefrontal cortex and the amygdala might make people prone to reactive violence, but that it is also necessary to contemplate additional cortical (i.e. insula, gyrus [angular, supramarginal, temporal, fusiform, superior, and middle frontal], anterior and posterior cingulated cortex) and subcortical brain structures (i.e. hippocampus, cerebellum, ventral striatum, and nucleus centralis superior) in order to explain a phenomenon as complex as violence. Moreover, we also described the neural pathways that might underlie proactive violence and feelings of revenge, highlighting the RSFC between the OFC, ventral striatal, angular gyrus, mid-occipital cortex, and cerebellum. Conclusions. The results from this synthesis and critical analysis of RSFC findings in several populations offer guidelines for future research and for developing a more accurate model of proneness to violence, in order to create effective treatment and prevention programs.

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Wireless logging of extracellular neuronal activity in the telencephalon of free-swimming salmonids

Animal Biotelemetry ◽

10.1186/s40317-021-00232-4 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Susumu Takahashi ◽

Takumi Hombe ◽

Riku Takahashi ◽

Kaoru Ide ◽

Shinichiro Okamoto ◽

...

Keyword(s):

Neuronal Activity ◽

Environmental Cues ◽

Fish Movement ◽

Water Tank ◽

Head Direction ◽

Free Swimming ◽

Rodent Brain ◽

River Migration ◽

Spike Waveforms ◽

The Brain

Abstract Background Salmonids return to the river where they were born in a phenomenon known as mother-river migration. The underpinning of migration has been extensively examined, particularly regarding the behavioral correlations of external environmental cues such as the scent of the mother-river and geomagnetic compass. However, neuronal underpinning remains elusive, as there have been no biologging techniques suited to monitor neuronal activity in the brain of large free-swimming fish. In this study, we developed a wireless biologging system to record extracellular neuronal activity in the brains of free-swimming salmonids. Results Using this system, we recorded multiple neuronal activities from the telencephalon of trout swimming in a rectangular water tank. As proof of principle, we examined the activity statistics for extracellular spike waveforms and timing. We found cells firing maximally in response to a specific head direction, similar to the head direction cells found in the rodent brain. The results of our study suggest that the recorded signals originate from neurons. Conclusions We anticipate that our biologging system will facilitate a more detailed investigation into the neural underpinning of fish movement using internally generated information, including responses to external cues.

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Predictive olfactory learning in Drosophila

Scientific Reports ◽

10.1038/s41598-021-85841-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Chang Zhao ◽

Yves F. Widmer ◽

Sören Diegelmann ◽

Mihai A. Petrovici ◽

Simon G. Sprecher ◽

...

Keyword(s):

Synaptic Plasticity ◽

Dopaminergic Neurons ◽

Mushroom Body ◽

Trace Conditioning ◽

Fruit Fly ◽

Olfactory Learning ◽

Shock Strength ◽

Behavioral Experiments ◽

Kenyon Cells ◽

Output Neurons

AbstractOlfactory learning and conditioning in the fruit fly is typically modelled by correlation-based associative synaptic plasticity. It was shown that the conditioning of an odor-evoked response by a shock depends on the connections from Kenyon cells (KC) to mushroom body output neurons (MBONs). Although on the behavioral level conditioning is recognized to be predictive, it remains unclear how MBONs form predictions of aversive or appetitive values (valences) of odors on the circuit level. We present behavioral experiments that are not well explained by associative plasticity between conditioned and unconditioned stimuli, and we suggest two alternative models for how predictions can be formed. In error-driven predictive plasticity, dopaminergic neurons (DANs) represent the error between the predictive odor value and the shock strength. In target-driven predictive plasticity, the DANs represent the target for the predictive MBON activity. Predictive plasticity in KC-to-MBON synapses can also explain trace-conditioning, the valence-dependent sign switch in plasticity, and the observed novelty-familiarity representation. The model offers a framework to dissect MBON circuits and interpret DAN activity during olfactory learning.

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