scholarly journals Regulation of modulatory cell activity across olfactory structures in Drosophila melanogaster

2019 ◽  
Author(s):  
Xiaonan Zhang ◽  
Kaylynn Coates ◽  
Andrew Dacks ◽  
Cengiz Gunay ◽  
J. Scott Lauritzen ◽  
...  
Keyword(s):  
Cognitive Processing ◽  
Antennal Lobe ◽  
Cell Activity ◽  
Brain Regions ◽  
Opposite Polarity ◽  
Second Order ◽  
Serotonergic Neuron ◽  
Local Interactions ◽  
Nervous Systems ◽  
Lateral Horn

AbstractAll centralized nervous systems possess modulatory neurons that arborize broadly across multiple brain regions. Such modulatory systems are critical for proper sensory, motor, and cognitive processing. How single modulatory neurons integrate into circuits within their target destination remains largely unexplored due to difficulties in both labeling individual cells and imaging across distal parts of the CNS. Here, we take advantage of an identified modulatory neuron in Drosophila that arborizes in multiple olfactory neuropils. We demonstrate that this serotonergic neuron has opposing odor responses in its neurites of the antennal lobe and lateral horn, first and second order olfactory neuropils respectively. Specifically, processes of this neuron in the antennal lobe have responses that are inhibitory and odor-independent, while lateral horn responses are excitatory and odor-specific. The results show that widespread modulatory neurons may not function purely as integrate-and-fire cells, but rather their transmitter release is locally regulated based on neuropil. As nearly all vertebrate and invertebrate neurons are subject to synaptic inputs along their dendro-axonic axis, it is likely that our findings generalize across phylogeny and other broadly-projecting modulatory systems.SignificanceThe centrifugal innervation of neuronal circuits is ubiquitous across centralized nervous systems. Such inputs often arise from modulatory neurons that arborize broadly throughout the brain. How information is integrated in such cells and how release from their distant terminals is regulated remains largely unknown. We show that a serotonergic neuron that innervates multiple stages of odor processing in Drosophila has distinct activity throughout its neurites, including opposite polarity responses in first and second order olfactory neuropils. Disparate activity arises from local interactions within each target region. Our results show that such neurons exhibit dendritic computation rather than somatic integration alone, and that examining local interactions at release sites is critical for understanding centrifugal innervation.

scholarly journals Cellular sources of TSPO expression in healthy and diseased brain

2021 ◽  
Author(s):  
Erik Nutma ◽  
Kelly Ceyzériat ◽  
Sandra Amor ◽  
Stergios Tsartsalis ◽  
Philippe Millet ◽  
...  
Keyword(s):  
Cell Activity ◽  
Brain Regions ◽  
Cellular Level ◽  
Translocator Protein ◽  
Disease Stage ◽  
Animal Models Of Disease ◽  
Positron Emission ◽  
Neuropsychiatric Diseases ◽  
Tspo Expression

AbstractThe 18 kDa translocator protein (TSPO) is a highly conserved protein located in the outer mitochondrial membrane. TSPO binding, as measured with positron emission tomography (PET), is considered an in vivo marker of neuroinflammation. Indeed, TSPO expression is altered in neurodegenerative, neuroinflammatory, and neuropsychiatric diseases. In PET studies, the TSPO signal is often viewed as a marker of microglial cell activity. However, there is little evidence in support of a microglia-specific TSPO expression. This review describes the cellular sources and functions of TSPO in animal models of disease and human studies, in health, and in central nervous system diseases. A discussion of methods of analysis and of quantification of TSPO is also presented. Overall, it appears that the alterations of TSPO binding, their cellular underpinnings, and the functional significance of such alterations depend on many factors, notably the pathology or the animal model under study, the disease stage, and the involved brain regions. Thus, further studies are needed to fully determine how changes in TSPO binding occur at the cellular level with the ultimate goal of revealing potential therapeutic pathways.

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

Synthesis

2019 ◽  
pp. 423-472
Author(s):  
Georg F. Striedter ◽  
R. Glenn Northcutt
Keyword(s):  
Functional Organization ◽  
Brain Size ◽  
Brain Regions ◽  
Brain Areas ◽  
Nervous Systems ◽  
Internal Organization ◽  
Vertebrate Brain ◽  
Relative Brain Size

After summarizing the earlier chapters, which focused on the evolution of specific lineages, this chapter examines general patterns in the evolution of vertebrate nervous systems. Most conspicuous is that relative brain size and complexity increased independently in many lineages. The proportional size of individual brain regions tends to change predictably with absolute brain size (and neurogenesis timing), but the scaling rules vary across lineages. Attempts to link variation in the size of individual brain areas (or entire brains) to behavior are complicated in part because the connections, internal organization, and functions of individual brain regions also vary across phylogeny. In addition, major changes in the functional organization of vertebrate brains were caused by the emergence of novel brain regions (e.g., neocortex in mammals and area dorsalis centralis in teleosts) and novel circuits. These innovations significantly modified the “vertebrate brain Bauplan,” but their mechanistic origins and implications require further investigation.

scholarly journals Effects of long-term cocaine self-administration on brain resting-state functional connectivity in nonhuman primates

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Stephen J. Kohut ◽  
Dionyssios Mintzopoulos ◽  
Brian D. Kangas ◽  
Hannah Shields ◽  
Kelly Brown ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Cognitive Processing ◽  
Resting State ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Resting State Functional Connectivity ◽  
Self Administration ◽  
Chronic Cocaine

AbstractLong-term cocaine use is associated with a variety of neural and behavioral deficits that impact daily function. This study was conducted to examine the effects of chronic cocaine self-administration on resting-state functional connectivity of the dorsal anterior cingulate (dACC) and putamen—two brain regions involved in cognitive function and motoric behavior—identified in a whole brain analysis. Six adult male squirrel monkeys self-administered cocaine (0.32 mg/kg/inj) over 140 sessions. Six additional monkeys that had not received any drug treatment for ~1.5 years served as drug-free controls. Resting-state fMRI imaging sessions at 9.4 Tesla were conducted under isoflurane anesthesia. Functional connectivity maps were derived using seed regions placed in the left dACC or putamen. Results show that cocaine maintained robust self-administration with an average total intake of 367 mg/kg (range: 299–424 mg/kg). In the cocaine group, functional connectivity between the dACC seed and regions primarily involved in motoric behavior was weaker, whereas connectivity between the dACC seed and areas implicated in reward and cognitive processing was stronger. In the putamen seed, weaker widespread connectivity was found between the putamen and other motor regions as well as with prefrontal areas that regulate higher-order executive function; stronger connectivity was found with reward-related regions. dACC connectivity was associated with total cocaine intake. These data indicate that functional connectivity between regions involved in motor, reward, and cognitive processing differed between subjects with recent histories of cocaine self-administration and controls; in dACC, connectivity appears to be related to cumulative cocaine dosage during chronic exposure.

scholarly journals The Antennal Pathway of Dragonfly Nymphs, from Sensilla to the Brain

Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 886
Author(s):  
Silvana Piersanti ◽  
Manuela Rebora ◽  
Gianandrea Salerno ◽  
Sylvia Anton
Keyword(s):  
Brain Structure ◽  
Antennal Lobe ◽  
Sensory Information ◽  
Brain Structures ◽  
Brain Regions ◽  
Adult Brain ◽  
Published Data ◽  
Antennal Sensilla ◽  
Aquatic Life ◽  
The Brain

Dragonflies are hemimetabolous insects, switching from an aquatic life style as nymphs to aerial life as adults, confronted to different environmental cues. How sensory structures on the antennae and the brain regions processing the incoming information are adapted to the reception of fundamentally different sensory cues has not been investigated in hemimetabolous insects. Here we describe the antennal sensilla, the general brain structure, and the antennal sensory pathways in the last six nymphal instars of Libellula depressa, in comparison with earlier published data from adults, using scanning electron microscopy, and antennal receptor neuron and antennal lobe output neuron mass-tracing with tetramethylrhodamin. Brain structure was visualized with an anti-synapsin antibody. Differently from adults, the nymphal antennal flagellum harbors many mechanoreceptive sensilla, one olfactory, and two thermo-hygroreceptive sensilla at all investigated instars. The nymphal brain is very similar to the adult brain throughout development, despite the considerable differences in antennal sensilla and habitat. Like in adults, nymphal brains contain mushroom bodies lacking calyces and small aglomerular antennal lobes. Antennal fibers innervate the antennal lobe similar to adult brains and the gnathal ganglion more prominently than in adults. Similar brain structures are thus used in L. depressa nymphs and adults to process diverging sensory information.

scholarly journals Brain Connectivity Analysis Under Semantic Vigilance and Enhanced Mental States

2019 ◽  
Vol 9 (12) ◽  
pp. 363 ◽  
Author(s):  
Fares Al-Shargie ◽  
Usman Tariq ◽  
Omnia Hassanin ◽  
Hasan Mir ◽  
Fabio Babiloni ◽  
...  
Keyword(s):  
Cognitive Processing ◽  
Right Hemisphere ◽  
Brain Connectivity ◽  
Vigilance Task ◽  
Mental States ◽  
Brain Regions ◽  
Emotional States ◽  
Processing Efficiency ◽  
Vigilance State ◽  
The Right

In this paper, we present a method to quantify the coupling between brain regions under vigilance and enhanced mental states by utilizing partial directed coherence (PDC) and graph theory analysis (GTA). The vigilance state is induced using a modified version of stroop color-word task (SCWT) while the enhancement state is based on audio stimulation with a pure tone of 250 Hz. The audio stimulation was presented to the right and left ears simultaneously for one-hour while participants perform the SCWT. The quantification of mental states was performed by means of statistical analysis of indexes based on GTA, behavioral responses of time-on-task (TOT), and Brunel Mood Scale (BRMUS). The results show that PDC is very sensitive to vigilance decrement and shows that the brain connectivity network is significantly reduced with increasing TOT, p < 0.05. Meanwhile, during the enhanced state, the connectivity network maintains high connectivity as time passes and shows significant improvements compared to vigilance state. The audio stimulation enhances the connectivity network over the frontal and parietal regions and the right hemisphere. The increase in the connectivity network correlates with individual differences in the magnitude of the vigilance enhancement assessed by response time to stimuli. Our results provide evidence for enhancement of cognitive processing efficiency with audio stimulation. The BRMUS was used to evaluate the emotional states of vigilance task before and after using the audio stimulation. BRMUS factors, such as fatigue, depression, and anger, significantly decrease in the enhancement group compared to vigilance group. On the other hand, happy and calmness factors increased with audio stimulation, p < 0.05.

Optimal Sequential Detection of Stimuli from Multiunit Recordings Taken in Densely Populated Brain Regions

2012 ◽  
Vol 24 (4) ◽  
pp. 895-938 ◽  
Author(s):  
Nir Nossenson ◽  
Hagit Messer
Keyword(s):  
Order Statistics ◽  
Single Neuron ◽  
Brain Regions ◽  
Second Order ◽  
Detection Scheme ◽  
Second Order Statistics ◽  
Optimal Detector ◽  
Electrode Voltage ◽  
The Subject ◽  
High Pass

We address the problem of detecting the presence of a recurring stimulus by monitoring the voltage on a multiunit electrode located in a brain region densely populated by stimulus reactive neurons. Published experimental results suggest that under these conditions, when a stimulus is present, the measurements are gaussian with typical second-order statistics. In this letter we systematically derive a generic, optimal detector for the presence of a stimulus in these conditions and describe its implementation. The optimality of the proposed detector is in the sense that it maximizes the life span (or time to injury) of the subject. In addition, we construct a model for the acquired multiunit signal drawing on basic assumptions regarding the nature of a single neuron, which explains the second-order statistics of the raw electrode voltage measurements that are high-pass-filtered above 300 Hz. The operation of the optimal detector and that of a simpler suboptimal detection scheme is demonstrated by simulations and on real electrophysiological data.

Effects of Chaihu-Guizhi-Ganji on the Levels of Monoamines and Their Related Substances, and Acetylcholine in Discrete Brain Regions of Mice

1996 ◽  
Vol 24 (01) ◽  
pp. 53-64 ◽  
Author(s):  
Tadanobu ltoh ◽  
Seisuke Michijiri ◽  
Shigeo Murai ◽  
Hiroko Saito ◽  
Hiroshi Saito ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Mouse Brain ◽  
Corpus Striatum ◽  
Repeated Administration ◽  
Brain Regions ◽  
Single Administration ◽  
Nervous Systems ◽  
Related Substances

The effects of the extract powder (CggT) from Chaihu-Guizhi-Gajiang-Tang (Saiko-keishi-kankyo-to, in Japanese) on the monoamines and their related substances and the acetylcholine in mouse brain were examined. 1) A single administration of CggT significantly increased the levels of HVA and 5-HIAA in the cerebral cortex, hypothalamus, corpus striatum and hippocampus at 75 mg/kg, and those in the hypothalamus, corpus striatum and hippocampus at 750 mg/kg. 2) The repeated administration of CggT significantly increased the level of 5-HT in the hippocampus at 75 mg/kg, and the levels of 5-HT in the corpus striatum and of NE and 5-HT in the hippocampus at 750 mg/kg. 3) The level of ACh was significantly increased in the hypothalamus alone after single administration of CggT. These findings suggest that CggT stimulates function of the dopaminergic and serotonergic nervous systems in mice, but not most of the NEnergic and cholinergic nervous systems.

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