Cytophysiology of neurosecretory axon terminals in the brain of an annelid (Ophryotrocha puerilis, Polychaeta)

1991 ◽  
Vol 264 (2) ◽  
pp. 339-345 ◽  
Author(s):  
A. Schlawny ◽  
T. Hamann ◽  
M. A. M�ller ◽  
H. -D. Pfannenstiel
Keyword(s):  
Axon Terminals ◽  
Neurosecretory Axon ◽  
Neurosecretory Axon Terminals ◽  
The Brain

Fine Structure of the Crayfish Sinus Gland

1967 ◽  
Vol 25 ◽  
pp. 12-13
Author(s):  
Ann Heffington Bunt ◽  
Ebert A. Ashby
Keyword(s):  
Procambarus Clarkii ◽  
Retinal Pigment ◽  
Secretory Product ◽  
Neurosecretory Granules ◽  
Sinus Gland ◽  
Land Crab ◽  
Blood Sinus ◽  
Axon Terminals ◽  
Neurosecretory Axon ◽  
Neurosecretory Axon Terminals

The sinus gland of the crayfish, Procambarus clarkii, is located on the dorsum of the eyestalk, just beneath the exoskeleton and adjacent to the medullae interna and externa optic ganglia. It functions to secrete a variety of proteinaceous hormones, including the erythrophore concentrating hormone, melanophore dispersing hormone, molt inhibiting hormone, diabetogenic hormone, distal retinal pigment hormone, and ovary inhibiting hormone.The gland is composed of numerous neurosecretory axon terminals clustered about a branching blood sinus. The neurosecretory axons arise from cells lying some distance away from the sinus gland, in the medulla terminal is X-organ, the brain, and possibly the thoracic ganglion. The hormones are manufactured in the perikarya of these cells and transported through the axons to their terminals in the sinus gland for storage and release into the blood sinus.Small, electron dense spherules within the axons contain the hormone secretory product. These neurosecretory granules are very similar in morphology to those reported in the sinus glands of the dwarf crayfish, Cambarellus shufeldti, the land crab, Gecarcinus lateralis, and the Mediterranean isopod, Sguilla mantis. The sinus glands of each of these crustaceans contain two size ranges of neurosecretory granules: 1500-2000A and 500-900A.

scholarly journals Widespread inhibition, antagonism, and synergy in mouse olfactory sensory neurons in vivo

2019 ◽  
Author(s):  
Shigenori Inagaki ◽  
Ryo Iwata ◽  
Masakazu Iwamoto ◽  
Takeshi Imai
Keyword(s):  
Sensory Neurons ◽  
Calcium Imaging ◽  
Odorant Receptor ◽  
Sensory Information ◽  
Olfactory Sensory Neurons ◽  
Axon Terminals ◽  
Two Photon ◽  
Odor Mixtures ◽  
The Brain

SUMMARYSensory information is selectively or non-selectively inhibited and enhanced in the brain, but it remains unclear whether this occurs commonly at the peripheral stage. Here, we performed two-photon calcium imaging of mouse olfactory sensory neurons (OSNs) in vivo and found that odors produce not only excitatory but also inhibitory responses at their axon terminals. The inhibitory responses remained in mutant mice, in which all possible sources of presynaptic lateral inhibition were eliminated. Direct imaging of the olfactory epithelium revealed widespread inhibitory responses at OSN somata. The inhibition was in part due to inverse agonism toward the odorant receptor. We also found that responses to odor mixtures are often suppressed or enhanced in OSNs: Antagonism was dominant at higher odor concentrations, whereas synergy was more prominent at lower odor concentrations. Thus, odor responses are extensively tuned by inhibition, antagonism, and synergy, at the early peripheral stage, contributing to robust odor representations.

scholarly journals Functional dichotomy in spinal- vs prefrontal-projecting locus coeruleus modules splits descending noradrenergic analgesia from ascending aversion and anxiety in rats

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Stefan Hirschberg ◽  
Yong Li ◽  
Andrew Randall ◽  
Eric J Kremer ◽  
Anthony E Pickering
Keyword(s):  
Locus Coeruleus ◽  
Viral Vectors ◽  
Spontaneous Pain ◽  
Pain Model ◽  
Axon Terminals ◽  
Neuronal Populations ◽  
Functional Organisation ◽  
Neuropathic Pain Model ◽  
Brain And Spinal Cord ◽  
The Brain

The locus coeruleus (LC) projects throughout the brain and spinal cord and is the major source of central noradrenaline. It remains unclear whether the LC acts functionally as a single global effector or as discrete modules. Specifically, while spinal-projections from LC neurons can exert analgesic actions, it is not known whether they can act independently of ascending LC projections. Using viral vectors taken up at axon terminals, we expressed chemogenetic actuators selectively in LC neurons with spinal (LC:SC) or prefrontal cortex (LC:PFC) projections. Activation of the LC:SC module produced robust, lateralised anti-nociception while activation of LC:PFC produced aversion. In a neuropathic pain model, LC:SC activation reduced hind-limb sensitisation and induced conditioned place preference. By contrast, activation of LC:PFC exacerbated spontaneous pain, produced aversion and increased anxiety-like behaviour. This independent, contrasting modulation of pain-related behaviours mediated by distinct noradrenergic neuronal populations provides evidence for a modular functional organisation of the LC.

Axon terminals with unusual vesicles in the brain of the polychaete, Ophryotrocha puerilis

1982 ◽  
Vol 226 (1) ◽  
Author(s):  
ClaudiaB. Grothe
Keyword(s):  
Axon Terminals ◽  
The Brain

Protein products of the bacterial reporter gene are found within axon terminals in the brain of transgenic mice

1994 ◽  
Vol 168 (1-2) ◽  
pp. 76-80 ◽  
Author(s):  
Ryohachi Arai ◽  
Nobuyuki Karasawa ◽  
Shigeyuki Deura ◽  
Kazuto Kobayashi ◽  
Toshiharu Nagatsu ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Reporter Gene ◽  
Axon Terminals ◽  
The Brain

719 Transgene product is found within axon terminals in the brain of transgenic mice

1993 ◽  
Vol 18 ◽  
pp. S85
Author(s):  
Ryohachi Arai ◽  
Keiki Yamada ◽  
Tetsuya Fujii ◽  
Kazuto Kobayashi ◽  
Toshiharu Nagatsu ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Axon Terminals ◽  
The Brain

scholarly journals Serial synapse formation through filopodial competition for synaptic seeding factors

2018 ◽  
Author(s):  
M. Neset Özel ◽  
Abhishek Kulkarni ◽  
Amr Hasan ◽  
Josephine Brummer ◽  
Marian Moldenhauer ◽  
...  
Keyword(s):  
Synapse Formation ◽  
Growth Cones ◽  
Data Driven ◽  
Axon Pathfinding ◽  
Analysis Method ◽  
Formation Model ◽  
Axon Terminals ◽  
Winner Takes All ◽  
The Brain ◽  
Time Point

SummaryFollowing axon pathfinding, growth cones transition from stochastic filopodial exploration to the formation of a limited number of synapses. How the interplay of filopodia and synapse assembly ensures robust connectivity in the brain has remained a challenging problem. Here, we developed a new 4D analysis method for filopodial dynamics and a data-driven computational model of synapse formation for R7 photoreceptor axons in developing Drosophila brains. Our live data support a ‘serial synapse formation’ model, where at any time point only a single ‘synaptogenic’ filopodium suppresses the synaptic competence of other filopodia through competition for synaptic seeding factors. Loss of the synaptic seeding factors Syd-1 and Liprin-α leads to a loss of this suppression, filopodial destabilization and reduced synapse formation, which is sufficient to cause the destabilization of entire axon terminals. Our model provides a filopodial ‘winner-takes-all’ mechanism that ensures the formation of an appropriate number of synapses.

scholarly journals Appetite controlled by a cholecystokinin nucleus of the solitary tract to hypothalamus neurocircuit

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Giuseppe D'Agostino ◽  
David J Lyons ◽  
Claudia Cristiano ◽  
Luke K Burke ◽  
Joseph C Madara ◽  
...  
Keyword(s):  
Body Weight ◽  
Paraventricular Nucleus ◽  
Anterograde Tracing ◽  
Solitary Tract ◽  
Close Apposition ◽  
Axon Terminals ◽  
Melanocortin 4 Receptor ◽  
Positive Valence ◽  
The Brain ◽  
Chemical Mediators

The nucleus of the solitary tract (NTS) is a key gateway for meal-related signals entering the brain from the periphery. However, the chemical mediators crucial to this process have not been fully elucidated. We reveal that a subset of NTS neurons containing cholecystokinin (CCKNTS) is responsive to nutritional state and that their activation reduces appetite and body weight in mice. Cell-specific anterograde tracing revealed that CCKNTS neurons provide a distinctive innervation of the paraventricular nucleus of the hypothalamus (PVH), with fibers and varicosities in close apposition to a subset of melanocortin-4 receptor (MC4RPVH) cells, which are also responsive to CCK. Optogenetic activation of CCKNTS axon terminals within the PVH reveal the satiating function of CCKNTS neurons to be mediated by a CCKNTS→PVH pathway that also encodes positive valence. These data identify the functional significance of CCKNTS neurons and reveal a sufficient and discrete NTS to hypothalamus circuit controlling appetite.

scholarly journals Multisensory expectations shape olfactory input to the brain

2018 ◽  
Author(s):  
Lindsey A. Czarnecki ◽  
Andrew H. Moberly ◽  
Cynthia D. Fast ◽  
Daniel J. Turkel ◽  
John P. McGann
Keyword(s):  
Neurotransmitter Release ◽  
Sensory Input ◽  
Gaba Release ◽  
External World ◽  
Mammalian Brain ◽  
Axon Terminals ◽  
Sensory Modalities ◽  
Olfactory Input ◽  
The Brain ◽  
Interneuron Activity

SummaryThe mammalian brain interprets sensory input based on prior multisensory knowledge of the external world, but it is unknown how this knowledge influences neural processing in individual sensory modalities. We found that GABAergic periglomerular interneuron populations in the olfactory bulb endogenously respond not only to odors but also to visual, auditory, and somatosensory stimuli in waking (but not anesthetized) mice. When these stimuli predict future odors, they evoke enhanced interneuron activity during the time odor normally occurs. When expectations are violated by omitting an expected “warning tone” before an odor, odor presentation evokes a burst of interneuron activity. The resulting GABA release presynaptically suppresses neurotransmitter release from the axon terminals of olfactory sensory neurons, the cells that transduce odor in the nasal epithelium and communicate this information to the brain. Expectations, even those evoked by cues in other sensory modalities, can thus affect the very first neurons in the olfactory system.

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