scholarly journals The wiring logic of an identified serotonergic neuron that spans sensory networks

2020 ◽  
Author(s):  
Kaylynn E. Coates ◽  
Steven A. Calle-Schuler ◽  
Levi M. Helmick ◽  
Victoria L. Knotts ◽  
Brennah N. Martik ◽  
...  
Keyword(s):  
Single Cell ◽  
Synaptic Input ◽  
Antennal Lobe ◽  
Projection Neurons ◽  
Dependent Manner ◽  
Serotonergic Neuron ◽  
Local Interneuron ◽  
Local Networks ◽  
First Order ◽  
Specific Input

AbstractSerotonergic neurons modulate diverse physiological and behavioral processes in a context-dependent manner, based on their complex connectivity. However, their connectivity has not been comprehensively explored at a single-cell resolution. Using a whole-brain EM dataset we determined the wiring logic of a broadly projecting serotonergic neuron (the “CSDn”) in Drosophila. Within the antennal lobe (AL; first-order olfactory region), the CSDn receives glomerulus-specific input and preferentially targets distinct local interneuron subtypes. Furthermore, the wiring logic of the CSDn differs between olfactory regions. The CSDn innervates the AL and lateral horn (LH), yet does not maintain the same synaptic relationship with individual projection neurons that also span both regions. Consistent with this, the CSDn has more distributed connectivity in the LH relative to the AL, preferentially synapsing with principal neuron types based on presumptive transmitter content. Lastly, we identify protocerebral neurons that provide abundant synaptic input to the CSDn. Our study demonstrates how an individual modulatory neuron can interact with local networks and integrate input from non-olfactory sources.

scholarly journals Transmitter Co-Expression Reveals Key Organizational Principles of Local Interneuron Heterogeneity in the Olfactory System

2017 ◽  
Author(s):  
Kristyn M. Lizbinski ◽  
Gary F. Marsat ◽  
Andrew M. Dacks
Keyword(s):  
Antennal Lobe ◽  
Expression Patterns ◽  
Receptor Expression ◽  
Projection Neurons ◽  
Local Interneuron ◽  
Local Interneurons ◽  
Receptor Neurons ◽  
Random Probability ◽  
Organizational Principles ◽  
Organizing Principles

AbstractHeterogeneity of individual neurons within a population expands the computational power of the entire neural network. However, the organizing principles that support heterogeneity within a neuronal class are often poorly understood. Here, we focus on a highly heterogeneous population of local interneurons whose traits co-vary seemingly at random. We asked if local interneurons (LNs) in the antennal lobe (AL) of Manduca sexta express fixed, predictable combinations of neurotransmitters, or if transmitter co-expression can be explained by random probability. We systematically determined the co-expression of neuropeptides and GABA by LNs and found variable patterns of co-expression for all neuropeptides, except for tachykininergic LNs which exhibited highly stereotyped co-expression on a neuron-by-neuron basis. To test if observed patterns of co-expression were random, we used a computational model and found that the probabilities of transmitter co-expression cannot be explained by independent expression of each transmitter. We also determined that setting a single rule in the model, while leaving the rest of the co-expression up to random probability, allowed the model to replicate the overall heterogeneity of transmitter co-expression across antennal lobe LNs. This implies that certain co-expression relationships contribute to the ground plan of the AL, but that otherwise, transmitter expression amongst LNs may be random, allowing heterogeneous co-expression patterns to emerge. Furthermore, neuropeptide receptor expression suggests that peptidergic signaling from LNs may simultaneously target olfactory receptor neurons, LNs and projection neurons, and thus the effects of different peptides do not segregate based on principal AL cell type. Our data suggest that while specific constraints may partially shape transmitter co-expression in LNs, a large amount of flexibility on a neuron-by-neuron basis produces heterogeneous network parameters.

Morphology and physiology of antennal lobe projection neurons in the hawkmoth Agrius convolvuli

2017 ◽  
Vol 98 ◽  
pp. 214-222 ◽  
Author(s):  
Takuya Nirazawa ◽  
Takeshi Fujii ◽  
Yoichi Seki ◽  
Shigehiro Namiki ◽  
Tomoki Kazawa ◽  
...  
Keyword(s):  
Antennal Lobe ◽  
Projection Neurons

Temporal summation properties of the olfactory projection neurons in the moth antennal lobe revealed by optogenetic stimulation

2011 ◽  
Vol 71 ◽  
pp. e79
Author(s):  
Masashi Tabuchi ◽  
Takeshi Sakurai ◽  
Hidefumi Mitsuno ◽  
Shigehiro Namiki ◽  
Ryo Minegishi ◽  
...  
Keyword(s):  
Antennal Lobe ◽  
Temporal Summation ◽  
Projection Neurons ◽  
Optogenetic Stimulation

Antennal Lobe Processing Increases Separability of Odor Mixture Representations in the Honeybee

2010 ◽  
Vol 103 (4) ◽  
pp. 2185-2194 ◽  
Author(s):  
Nina Deisig ◽  
Martin Giurfa ◽  
Jean Christophe Sandoz
Keyword(s):  
Antennal Lobe ◽  
Second Order ◽  
Insect Brain ◽  
Output Level ◽  
Local Networks ◽  
Odor Mixture ◽  
Receptor Neurons ◽  
Evoked Activity ◽  
Input Level ◽  
Olfactory Space

Local networks within the primary olfactory centers reformat odor representations from olfactory receptor neurons to second-order neurons. By studying the rules underlying mixture representation at the input to the antennal lobe (AL), the primary olfactory center of the insect brain, we recently found that mixture representation follows a strict elemental rule in honeybees: the more a component activates the AL when presented alone, the more it is represented in a mixture. We now studied mixture representation at the output of the AL by imaging a population of second-order neurons, which convey AL processed odor information to higher brain centers. We systematically measured odor-evoked activity in 22 identified glomeruli in response to four single odorants and all their possible binary, ternary and quaternary mixtures. By comparing input and output responses, we determined how the AL network reformats mixture representation and what advantage this confers for odor discrimination. We show that increased inhibition within the AL leads to more synthetic, less elemental, mixture representation at the output level than that at the input level. As a result, mixture representations become more separable in the olfactory space, thus allowing better differentiation among floral blends in nature.

Development of an identified serotonergic neuron in the antennal lobe of the moth and effects of reduction in serotonin during construction of olfactory glomeruli

1995 ◽  
Vol 28 (2) ◽  
pp. 248-267 ◽  
Author(s):  
Lynne A. Oland ◽  
Sheila R. Kirschenbaum ◽  
Wendy M. Pott ◽  
Alison R. Mercer ◽  
Leslie P. Tolbert
Keyword(s):  
Antennal Lobe ◽  
Serotonergic Neuron ◽  
Olfactory Glomeruli

scholarly journals Single-cell transcriptomic analysis identifies neocortical developmental differences between human and mouse

2020 ◽  
Author(s):  
Ziheng Zhou ◽  
Shuguang Wang ◽  
Dengwei Zhang ◽  
Xiaosen Jiang ◽  
Jie Li ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Single Cell ◽  
Developmental Trajectories ◽  
Expression Patterns ◽  
Development Stage ◽  
Inhibitory Neurons ◽  
Projection Neurons ◽  
Cerebral Cortex Development ◽  
Excitatory Neurons ◽  
Human And Mouse

AbstractBackgroundThe specification and differentiation of neocortical projection neurons is a complex process under precise molecular regulation; however, little is known about the similarities and differences in cerebral cortex development between human and mouse at single-cell resolution.ResultsHere, using single-cell RNA-seq (scRNA-seq) data we explore the divergence and conservation of human and mouse cerebral cortex development using 18,446 and 7,610 neocortical cells. Systematic cross-species comparison reveals that the overall transcriptome profile in human cerebral cortex is similar to that in mouse such as cell types and their markers genes. By single-cell trajectories analysis we find human and mouse excitatory neurons have different developmental trajectories of neocortical projection neurons, ligand-receptor interactions and gene expression patterns. Further analysis reveals a refinement of neuron differentiation that occurred in human but not in mouse, suggesting that excitatory neurons in human undergo refined transcriptional states in later development stage. By contrast, for glial cells and inhibitory neurons we detected conserved developmental trajectories in human and mouse.ConclusionsTaken together, our study integrates scRNA-seq data of cerebral cortex development in human and mouse, and uncovers distinct developing models in neocortical projection neurons. The earlier activation of cognition -related genes in human may explain the differences in behavior, learning or memory abilities between the two species.

scholarly journals Differences in spike generation instead of synaptic inputs determine the feature selectivity of two retinal cell types.

2021 ◽  
Author(s):  
Sophia Wienbar ◽  
Gregory Schwartz
Keyword(s):  
Synaptic Input ◽  
Ganglion Cells ◽  
Intrinsic Property ◽  
Retinal Cell ◽  
Projection Neurons ◽  
Functional Difference ◽  
Intrinsic Properties ◽  
Spike Generation ◽  
Synaptic Inputs ◽  
Feature Selectivity

The output of spiking neurons depends both on their synaptic inputs and on their intrinsic properties. Retinal ganglion cells (RGCs), the spiking projection neurons of the retina, comprise over 40 different types in mice and other mammals, each tuned to different features of visual scenes. The circuits providing synaptic input to different RGC types to drive feature selectivity have been studied extensively, but there has been substantially less research aimed at understanding how the intrinsic properties of RGCs differ and how those differences impact feature selectivity. Here, we introduce an RGC type in the mouse, the Bursty Suppressed-by-Contrast (bSbC) RGC, whose contrast selectivity is shaped by its intrinsic properties. Surprisingly, when we compare the bSbC RGC to the OFF sustained alpha (OFFsA) RGC that receives similar synaptic input, we find that the two RGC types exhibit starkly different responses to an identical stimulus. We identified spike generation as the key intrinsic property behind this functional difference; the bSbC RGC undergoes depolarization block in conditions where the OFFsA RGC maintains a high spike rate. Pharmacological experiments, imaging, and compartment modeling demonstrate that these differences in spike generation are the result of differences in voltage-gated sodium channel conductances. Our results demonstrate that differences in intrinsic properties allow these two RGC types to detect and relay distinct features of an identical visual stimulus to the brain.

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