scholarly journals Visual projection neurons in the Drosophila lobula link feature detection to distinct behavioral programs

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Ming Wu ◽  
Aljoscha Nern ◽  
W Ryan Williamson ◽  
Mai M Morimoto ◽  
Michael B Reiser ◽  
...  
Keyword(s):  
Visual Processing ◽  
Feature Detection ◽  
Brain Structures ◽  
Brain Regions ◽  
Projection Neurons ◽  
Small Object ◽  
Two Photon ◽  
Visual Projection ◽  
Anatomical Connection

Visual projection neurons (VPNs) provide an anatomical connection between early visual processing and higher brain regions. Here we characterize lobula columnar (LC) cells, a class of Drosophila VPNs that project to distinct central brain structures called optic glomeruli. We anatomically describe 22 different LC types and show that, for several types, optogenetic activation in freely moving flies evokes specific behaviors. The activation phenotypes of two LC types closely resemble natural avoidance behaviors triggered by a visual loom. In vivo two-photon calcium imaging reveals that these LC types respond to looming stimuli, while another type does not, but instead responds to the motion of a small object. Activation of LC neurons on only one side of the brain can result in attractive or aversive turning behaviors depending on the cell type. Our results indicate that LC neurons convey information on the presence and location of visual features relevant for specific behaviors.

scholarly journals Author response: Visual projection neurons in the Drosophila lobula link feature detection to distinct behavioral programs

2016 ◽  
Author(s):  
Ming Wu ◽  
Aljoscha Nern ◽  
W Ryan Williamson ◽  
Mai M Morimoto ◽  
Michael B Reiser ◽  
...  
Keyword(s):  
Feature Detection ◽  
Author Response ◽  
Projection Neurons ◽  
Visual Projection

scholarly journals Dopamine modulates the size of striatal projection neuron ensembles

2019 ◽  
Author(s):  
Marta Maltese ◽  
Jeffrey R. March ◽  
Alexander G. Bashaw ◽  
Nicolas X. Tritsch
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Projection Neuron ◽  
Projection Neurons ◽  
Voluntary Movements ◽  
Indirect Pathway ◽  
Two Photon ◽  
Direct Pathway ◽  
Brain Circuits

SUMMARYDopamine (DA) is a critical modulator of brain circuits that control voluntary movements, but our understanding of its influence on the activity of target neurons in vivo remains limited. Here, we use two-photon Ca2+ imaging to simultaneously monitor the activity of direct and indirect-pathway spiny projection neurons (SPNs) in the striatum of behaving mice during acute and prolonged manipulations of DA signaling. We find that, contrary to prevailing models, DA does not modulate activity rates in either pathway strongly or differentially. Instead, DA exerts a prominent influence on the overall number of direct and indirect pathway SPNs recruited during behavior. Chronic loss of midbrain DA neurons in a model of Parkinson’s disease selectively impacts direct pathway ensembles and profoundly alters how they respond to DA elevation. Our results indicate that DA regulates striatal output by dynamically reconfiguring its sparse ensemble code and provide novel insights into the pathophysiology of Parkinson’s disease.

scholarly journals Dopamine differentially modulates the size of projection neuron ensembles in the intact and dopamine-depleted striatum

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Marta Maltese ◽  
Jeffrey R March ◽  
Alexander G Bashaw ◽  
Nicolas X Tritsch
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Population Level ◽  
Projection Neuron ◽  
Projection Neurons ◽  
Voluntary Movements ◽  
Indirect Pathway ◽  
Two Photon ◽  
Brain Circuits

Dopamine (DA) is a critical modulator of brain circuits that control voluntary movements, but our understanding of its influence on the activity of target neurons in vivo remains limited. Here, we use two-photon Ca2+ imaging to monitor the activity of direct and indirect-pathway spiny projection neurons (SPNs) simultaneously in the striatum of behaving mice during acute and prolonged manipulations of DA signaling. We find that increasing and decreasing DA biases striatal activity towards the direct and indirect pathways, respectively, by changing the overall number of SPNs recruited during behavior in a manner not predicted by existing models of DA function. This modulation is drastically altered in a model of Parkinson's disease. Our results reveal a previously unappreciated population-level influence of DA on striatal output and provide novel insights into the pathophysiology of Parkinson's disease.

BBB transport and rapid tissue binding of cyclofoxy: comparison of active and inactive enantiomers

1990 ◽  
Vol 259 (4) ◽  
pp. H1278-H1287 ◽  
Author(s):  
R. Kawai ◽  
Y. Sawada ◽  
M. Channing ◽  
A. H. Newman ◽  
K. C. Rice ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Rank Order ◽  
Compartment Model ◽  
Brain Structures ◽  
Opiate Receptor ◽  
Brain Regions ◽  
Binding Model ◽  
Rapid Phase

The "rapid-phase" brain distribution of 3H-labeled enantiomers of the opiate receptor antagonist cyclofoxy (CF), receptor active (-) and inert (+) forms, was measured during 20- to 180-s intravenous infusion in rats. [14C]iodoantipyrine was coinfused during these experiments to obtain a simultaneous measure of blood flow. The influx clearance (K1) across the blood-brain barrier (BBB) and the rapid binding equilibrium constant (Keq) were estimated in different brain regions for both enantiomers (2-compartmental model); a possible receptor binding process (k3) was also examined for (-)-CF (3-compartment model). K1 (0.46-0.91 ml.min-1.g-1), the capillary permeability-surface area product (PS; 0.75 approximately 1.4 ml.min-1.g-1) and the tissue extraction fraction (E; 0.6-0.7) were found to be identical for both enantiomers in the nonreceptor binding model; Keq was identical in cerebellum but larger for (-)-CF in other brain structures. The difference in Keq between the enantiomers (2-compartment model) correlated with the rank order of opiate receptor density observed in vitro and in vivo. These results suggest that concomitant use of (-)-CF and (+)-CF will be useful for in vivo receptor binding analyses.

scholarly journals In vivo Binding of [3H]Nimodipine in Rat Brain after Transient Forebrain Ischemia

1994 ◽  
Vol 14 (3) ◽  
pp. 397-405 ◽  
Author(s):  
Shunya Takizawa ◽  
Matthew J. Hogan ◽  
Alastair M. Buchan ◽  
Antoine M. Hakim
Keyword(s):  
Cerebral Ischemia ◽  
Brain Structures ◽  
Brain Regions ◽  
Global Cerebral Ischemia ◽  
Therapeutic Window ◽  
Forebrain Ischemia ◽  
In Vivo Binding ◽  
Transient Forebrain Ischemia ◽  
Ca1 Region

We report the regional variation in relative in vivo binding of the l-type voltage sensitive calcium channel (VSCC) antagonist [3H]nimodipine to brain following transient forebrain ischemia in the rat. At 30-min of reperfusion after 20 min of forebrain ischemia, [3H]nimodipine binding was significantly increased in striatum, CA3 and CA4, and dentate relative to binding in sham-operated rats, suggesting that VSCCs were responding to ischemic depolarization. Two h following ischemia, binding in all brain structures returned to normal levels indicating repolarization of cell membranes. At 24 h of recirculation, increased [3H]nimodipine binding was again observed in striatum and dentate. Binding remained elevated in the striatum and dentate, and increased binding became evident in the CA1 region of the hippocampus after 48 h of reperfusion. With the exception of the dentate gyrus, the second rise in [3H]nimodipine binding anticipated or coincided with the observed regional ischemic cell changes. These observations in global cerebral ischemia support previous work indicating that in vivo binding of [3H]nimodipine to the l-type VSCC may be an early and sensitive indicator of impending ischemic injury. Such measurements may be of use in identifying vulnerable brain regions and defining a therapeutic window of opportunity in models of cerebral ischemia.

scholarly journals Adaptive optics two-photon endomicroscopy enables deep-brain imaging at synaptic resolution over large volumes

2020 ◽  
Vol 6 (40) ◽  
pp. eabc6521 ◽  
Author(s):  
Zhongya Qin ◽  
Congping Chen ◽  
Sicong He ◽  
Ye Wang ◽  
Kam Fai Tam ◽  
...  
Keyword(s):  
Brain Imaging ◽  
Adaptive Optics ◽  
Critical Role ◽  
Random Access ◽  
Brain Structures ◽  
Invasive Approach ◽  
Two Photon ◽  
Grin Lens ◽  
Deep Brain

Optical deep-brain imaging in vivo at high resolution has remained a great challenge over the decades. Two-photon endomicroscopy provides a minimally invasive approach to image buried brain structures, once it is integrated with a gradient refractive index (GRIN) lens embedded in the brain. However, its imaging resolution and field of view are compromised by the intrinsic aberrations of the GRIN lens. Here, we develop a two-photon endomicroscopy by adding adaptive optics based on direct wavefront sensing, which enables recovery of diffraction-limited resolution in deep-brain imaging. A new precompensation strategy plays a critical role to correct aberrations over large volumes and achieve rapid random-access multiplane imaging. We investigate the neuronal plasticity in the hippocampus, a critical deep brain structure, and reveal the relationship between the somatic and dendritic activity of pyramidal neurons.

scholarly journals Metabolic connectomics targeting brain pathology in dementia with Lewy bodies

2016 ◽  
Vol 37 (4) ◽  
pp. 1311-1325 ◽  
Author(s):  
Silvia P Caminiti ◽  
Marco Tettamanti ◽  
Arianna Sala ◽  
Luca Presotto ◽  
Sandro Iannaccone ◽  
...  
Keyword(s):  
Dementia With Lewy Bodies ◽  
Estimation Method ◽  
Lewy Bodies ◽  
Occipital Cortex ◽  
Brain Structures ◽  
Brain Regions ◽  
Normal Brain ◽  
Whole Brain ◽  
Metabolic Connectivity

Dementia with Lewy bodies is characterized by α-synuclein accumulation and degeneration of dopaminergic and cholinergic pathways. To gain an overview of brain systems affected by neurodegeneration, we characterized the [18F]FDG-PET metabolic connectivity in 42 dementia with Lewy bodies patients, as compared to 42 healthy controls, using sparse inverse covariance estimation method and graph theory. We performed whole-brain and anatomically driven analyses, targeting cholinergic and dopaminergic pathways, and the α-synuclein spreading. The first revealed substantial alterations in connectivity indexes, brain modularity, and hubs configuration. Namely, decreases in local metabolic connectivity within occipital cortex, thalamus, and cerebellum, and increases within frontal, temporal, parietal, and basal ganglia regions. There were also long-range disconnections among these brain regions, all supporting a disruption of the functional hierarchy characterizing the normal brain. The anatomically driven analysis revealed alterations within brain structures early affected by α-synuclein pathology, supporting Braak’s early pathological staging in dementia with Lewy bodies. The dopaminergic striato-cortical pathway was severely affected, as well as the cholinergic networks, with an extensive decrease in connectivity in Ch1-Ch2, Ch5-Ch6 networks, and the lateral Ch4 capsular network significantly towards the occipital cortex. These altered patterns of metabolic connectivity unveil a new in vivo scenario for dementia with Lewy bodies underlying pathology in terms of changes in whole-brain metabolic connectivity, spreading of α-synuclein, and neurotransmission impairment.

scholarly journals Prepronociceptin expressing neurons in the extended amygdala encode and promote rapid arousal responses to motivationally salient stimuli

2020 ◽  
Author(s):  
Jose Rodriguez-Romaguera ◽  
Randall L Ung ◽  
Hiroshi Nomura ◽  
James M Otis ◽  
Marcus L Basiri ◽  
...  
Keyword(s):  
Brain Regions ◽  
Sequencing Data ◽  
Bed Nucleus ◽  
Two Photon ◽  
Motivational States ◽  
Motivational Salience ◽  
Excitatory Responses ◽  
Locomotor Behaviors ◽  
Pupillary Size

ABSTRACTMotivational states are complex and consist of cognitive, emotional, and physiological components controlled by a network across multiple brain regions. An integral component of this neural circuitry is the bed nucleus of the stria terminalis (BNST). Here, we identified a subpopulation of neurons within BNST expressing the gene prepronociceptin (PnocBNST), that can modulate the rapid changes in physiological arousal that occur upon exposure to stimuli with motivational salience. Using in vivo two-photon calcium imaging we found that excitatory responses from individual PnocBNST neurons directly corresponded with rapid increases in pupillary size and occurred upon exposure to both aversive and rewarding odors. Furthermore, optogenetic activation of these neurons increased pupillary size, but did not alter approach/avoidance or locomotor behaviors. These findings suggest that excitatory responses in PnocBNST neurons encode rapid arousal responses irrespective of tested behaviors. Further histological, electrophysiological, and single-cell RNA sequencing data revealed that PnocBNST neurons are composed of genetically and anatomically identifiable subpopulations that can be further investigated. Taken together, our findings demonstrate a key role for a PnocBNST neuronal ensemble in encoding the rapid arousal responses that are triggered by motivational stimuli.

scholarly journals Minimally invasive deep-brain imaging through a 50 μm-core multimode fibre

2018 ◽  
Author(s):  
Sebastian A. Vasquez-Lopez ◽  
Vadim Koren ◽  
Martin Plöschner ◽  
Zahid Padamsey ◽  
Tomáš Čižmár ◽  
...  
Keyword(s):  
High Resolution ◽  
Brain Imaging ◽  
Light Propagation ◽  
Neural Circuit ◽  
Complex Refractive Index ◽  
Brain Structures ◽  
Brain Regions ◽  
Long Distance ◽  
Deep Brain

AbstractAchieving optical access to deep-brain structures represents an important step towards the goal of understanding the mammalian central nervous system. The complex refractive index distribution within brain tissue introduces severe aberrations to long-distance light propagation thereby prohibiting image reconstruction using currently available non-invasive techniques. In an attempt to overcome this challenge endoscopic approaches have been adopted, principally in the form of fibre bundles or GRIN-lens based endoscopes. Unfortunately, these approaches create substantial mechanical lesions of the tissue precipitating neuropathological responses that include inflammation and gliosis. Together, lesions and the associated neuropathology may compromise neural circuit performance. By replacing Fourier-based image relay with a holographic approach, we have been able to reduce the volume of tissue lesion by more than 100-fold, while preserving diffraction-limited imaging performance. Here we demonstrate high-resolution fluorescence imaging of neuronal structures, dendrites and synaptic specialisations, in deep-brain regions of living mice. These results represent a major breakthrough in the compromise between high-resolution imaging and tissue damage, heralding new possibilities for deep-brain imaging in vivo.

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