Keeping Sensory Cells and Evolving Neurons to Connect Them to the Brain: Molecular Conservation and Novelties in Vertebrate Ear Development

The light environment greatly impacts human alertness, mood, and cognition by acute regulation of physiology and indirect alignment of circadian rhythms. Both processes require the melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs), but the relevant downstream brain areas remain elusive. ipRGCs project widely in the brain, including to the central circadian pacemaker, the suprachiasmatic nucleus (SCN). Here we show that body temperature and sleep responses to light are absent after genetic ablation of all ipRGCs except a subpopulation that projects to the SCN. Furthermore, by chemogenetic activation of the ipRGCs that avoid the SCN, we show that these cells are sufficient for acute changes in body temperature. Our results challenge the idea that the SCN is a major relay for the acute effects of light on non-image forming behaviors and identify the sensory cells that initiate light's profound effects on body temperature and sleep.

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Novel gene expressed in nasal region influences outgrowth of olfactory axons and migration of luteinizing hormone-releasing hormone (LHRH) neurons

Genes & Development ◽

10.1101/gad.14.14.1824 ◽

2000 ◽

Vol 14 (14) ◽

pp. 1824-1834 ◽

Cited By ~ 1

Author(s):

P.R. Kramer ◽

Susan Wray

Keyword(s):

Reproductive Function ◽

Neuroendocrine Cells ◽

Sensory Cells ◽

Axon Pathfinding ◽

Nasal Tissue ◽

Nasal Region ◽

And Migration ◽

Axonal Targeting ◽

Guidance Molecule ◽

The Brain

Although a variety of cues have been implicated in axonal targeting during embryogenesis and regeneration, the precise mechanisms guiding olfactory axons remain unclear. Appropriate olfactory axon pathfinding is essential for functional chemoreceptive and pheromone receptive systems. Olfactory axon pathfinding is also necessary for establishment of the neuroendocrine LHRH system, cells critical for reproductive function. LHRH cells exhibit neurophilic migration moving from the nasal region along olfactory axons into the brain. Factors involved in the migration of these neuroendocrine cells are as yet unresolved. We report identification of a novel factor termed nasal embryonic LHRH factor (NELF) that was discovered in a differential screen of migrating versus nonmigrating primary LHRH neurons. NELF is expressed in PNS and CNS tissues during embryonic development, including olfactory sensory cells and LHRH cells. NELF antisense experiments indicate that a reduction in NELF expression decreases olfactory axon outgrowth and the number of LHRH neurons that migrate out of the nasal tissue. These results demonstrate that NELF plays a role as a common guidance molecule for olfactory axon projections and subsequently, either directly or indirectly, in the neurophilic migration of LHRH cells.

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Evidence for the cholinergic markers ChAT and vAChT in sensory cells of the developing antennal nervous system of the desert locust Schistocerca gregaria

Invertebrate Neuroscience ◽

10.1007/s10158-020-00252-4 ◽

2020 ◽

Vol 20 (4) ◽

Author(s):

Erica Ehrhardt ◽

George Boyan

Keyword(s):

Nervous System ◽

Schistocerca Gregaria ◽

Central Complex ◽

Sensory Cells ◽

Desert Locust ◽

Cholinergic Transmission ◽

Sensory Axons ◽

First Instar ◽

The Brain ◽

Antennal Nerve

AbstractSensory and motor systems in insects with hemimetabolous development must be ready to mediate adaptive behavior directly on hatching from the egg. For the desert locust S. gregaria, cholinergic transmission from antennal sensillae to olfactory or mechanosensory centers in the brain requires that choline acetyltransferase (ChAT) and the vesicular acetylcholine transporter (vAChT) already be present in sensory cells in the first instar. In this study, we used immunolabeling to demonstrate that ChAT and vAChT are both expressed in sensory cells from identifiable sensilla types in the immature antennal nervous system. We observed ChAT expression in dendrites, neurites and somata of putative basiconic-type sensillae at the first instar stage. We also detected vAChT in the sensory axons of these sensillae in a major antennal nerve tract. We then examined whether evidence for cholinergic transmission is present during embryogenesis. Immunolabeling confirms that vAChT is expressed in somata typical of campaniform sensillae, as well as in small sensory cell clusters typically associated with either a large basiconic or coeloconic sensilla, at 99% of embryogenesis. The vAChT is also expressed in the somata of these sensilla types in multiple antennal regions at 90% of embryogenesis, but not at earlier (70%) embryonic stages. Neuromodulators are known to appear late in embryogenesis in neurons of the locust central complex, and the cholinergic system of the antenna may also only reach maturity shortly before hatching.

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Distinct ipRGC subpopulations mediate light’s acute and circadian effects on body temperature and sleep

eLife ◽

10.7554/elife.44358 ◽

2019 ◽

Vol 8 ◽

Cited By ~ 19

Author(s):

Alan C Rupp ◽

Michelle Ren ◽

Cara M Altimus ◽

Diego C Fernandez ◽

Melissa Richardson ◽

...

Keyword(s):

Body Temperature ◽

Ganglion Cells ◽

Light Exposure ◽

Sensory Cells ◽

Retinal Ganglion ◽

Acute Effects ◽

Genetic Ablation ◽

Acute Changes ◽

Mood And Cognition ◽

The Brain

The light environment greatly impacts human alertness, mood, and cognition by both acute regulation of physiology and indirect alignment of circadian rhythms. These processes require the melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs), but the relevant downstream brain areas involved remain elusive. ipRGCs project widely in the brain, including to the central circadian pacemaker, the suprachiasmatic nucleus (SCN). Here we show that body temperature and sleep responses to acute light exposure are absent after genetic ablation of all ipRGCs except a subpopulation that projects to the SCN. Furthermore, by chemogenetic activation of the ipRGCs that avoid the SCN, we show that these cells are sufficient for acute changes in body temperature. Our results challenge the idea that the SCN is a major relay for the acute effects of light on non-image forming behaviors and identify the sensory cells that initiate light’s profound effects on body temperature and sleep.

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Observation of neuronal activity using real-time voltage-sensitive dye imaging

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122782 ◽

1992 ◽

Vol 50 (1) ◽

pp. 476-477

Author(s):

John S. Kauer ◽

Angel Cinelli ◽

David Wellis ◽

Joel White

Keyword(s):

Neuronal Activity ◽

Neural Circuits ◽

Brain Activity ◽

Single Cells ◽

Pyramidal Cells ◽

Optical Recording ◽

Sensory Cells ◽

Large Numbers ◽

The Brain ◽

Prepyriform Cortex

Sensory systems are confronted with the problem of taking “information” in the outside world and encoding and manipulating it in forms that can be used in the neuronal world. A major challenge is to document how the transition between these worlds takes place (transduction) and, once it has taken place, how the data are manipulated by neural circuits (integration). Since the brain is an intrinsically parallel device, carrying out many functions simultaneously, it would appear as important to record brain activity in a similarly parallel manner as to record events in single cells and membranes. Optical recording of neuronal events offers a first step toward thing to observe events that are distributed among the cells and processes of a neuronal network.In the sense of smell odors appear to be encoded by activity distributed across many neurons at each level of the system studied so far, from the sensory cells in the nose to the pyramidal cells in prepyriform cortex (for review see). Thus, to elucidate how the molecular properties of odorants are represented by neurons it is probably necessary to observe the patterns of distributed activation. The distribution of activity across many neuronal elements, in contrast to representing odor molecules by dedicated “labelled lines”, confers redundancy and fault tolerance on a system that is crucial for complex behaviors that underly survival for many animals species, as well as providing flexibility for being sensitive to large numbers of compounds.

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The Ontogeny and Comparative Anatomy of some Protocerebral Sense Organs in Notostracan Phyllopods

Journal of Cell Science ◽

10.1242/jcs.s3-100.51.445 ◽

1959 ◽

Vol s3-100 (51) ◽

pp. 445-462

Author(s):

ERIK DAHL

Keyword(s):

Optic Nerve ◽

Distal Part ◽

Compound Eye ◽

Comparative Anatomy ◽

Sensory Cells ◽

Compound Eyes ◽

Sense Organs ◽

Proliferation Zone ◽

Lamina Ganglionaris ◽

The Brain

1. An investigation of the ontogeny of some of the protocerebral sense organs of Triops was carried out. 2. Attention is called to the presence of a frontal proliferation zone of great importance in the growth of the nauplius and compound eyes. 3. With respect to the nauplius eyes it is shown that to the small tripartite nauplius eye present at hatching additions are contributed partly by the dorso-lateral lobes of the brain, partly by the proliferation zone. This complicated mode of derivation of the nauplius eye is reflected in the arrangement of the nerves. The so-called upper lateral nauplius eye nerve in Triops is shown to be the remnant of the connexion between the nauplius eye and the ganglion opticum of the compound eye, and the evidence suggests that it is not really to be regarded as an optic nerve of the nauplius eye. 4. It is shown that the proliferation zone is mainly or exclusively responsible for the formation not only of the distal part of the compound eye but also of the ganglion layer of the lamina ganglionaris and of the distal part of the ganglion layer of the medulla. 5. The dorsal paired frontal organs as described by Claus (1873) are identified with a group of sensory cells situated above the lateral nauplius eye in the adults of Triops, and the ontogenetical processes involved in their dislocation are traced. 6. The group of cells in the neighbourhood of the ganglion opticum supposed by Wenke (1908) and Hanstrom (1931) to be identical with the frontal organs found by Claus (1873) probably constitute a neurosecretory organ. 7. It is shown that despite great topographical differences the ontogeny of the protocerebral sense organs of Artemia in many respects follows the same pattern as in Triops.

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Locust Wind Receptors

Journal of Experimental Biology ◽

10.1242/jeb.50.2.335 ◽

1969 ◽

Vol 50 (2) ◽

pp. 335-348 ◽

Cited By ~ 1

Author(s):

JEFFREY M. CAMHI

Keyword(s):

Sensory Cell ◽

Hair Shaft ◽

Sensory Cells ◽

Suboesophageal Ganglion ◽

Optimal Direction ◽

Specific Direction ◽

Prothoracic Ganglion ◽

The Face ◽

The Brain ◽

Force Asymmetry

1. The sensory cell innervating each wind-receptor hair on the face of the desert locust responds to wind with a slowly adapting train of impulses. 2. Each sensory cell responds maximally to wind flowing in a specific direction. The optimal direction for any sense cell is the same as the angle of curvature of its hair shaft. 3. The optimal wind direction has been determined for each sensory cell of the organ. 4. Three independently measured factors determine a sense cell's direction response :drag asymmetry of the curved shaft, elastic force asymmetry of the socket, and the eccentric attachment of the dendrite. 5. The sensory cells probably continue uninterrupted through the brain, synapsing first in the suboesophageal ganglion. 6. An accessory neurone of unknown function and unidentified central connexions links each seta with the prothoracic ganglion.

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The Role of the outer Conducting Epithelium in the Behaviour of Salp Oozooids

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400020154 ◽

1982 ◽

Vol 62 (1) ◽

pp. 125-132 ◽

Cited By ~ 6

Author(s):

Q. Bone

Keyword(s):

Electrical Stimulation ◽

Locomotor Activity ◽

Gap Junctions ◽

Action Potentials ◽

Sensory Cells ◽

Similar System ◽

Locomotor Behaviour ◽

The Brain ◽

Stimulation Of

INTRODUCTIONBoth the inner and outer epithelia of salps propagate action potentials (Mackie & Bone, 1977). Skin pulses in the outer epithelium underlying the test (OSPs) evoked by mechanical or electrical stimulation of the epithelium ‘enter’ the brain and may alter the regular rhythmic locomotor activity (Mackie & Bone, 1977; Anderson et al. 1979). The route of'entry’ has not been determined, but has been assumed to be via the axons of the scattered mechanoreceptor sensory cells lying in the outer epithelium. The OSP system would thus operate to extend the sensory field of such cells, as in the appendicularian Oikopleura (Bone & Mackie, 1975; Bone & Ryan, 1979) where two sensory cells are coupled to a conducting epithelium.Salps alternate generations between the solitary asexual oozooid, and the aggregated sexual blastozooids (budded from the stolon of the oozooid). The linked blastozooids form chains, along which OSPs pass to regulate the locomotor behaviour of individual zooids in the chain. The zooids are not linked by gap junctions, and OSPs pass along the chain in a complex.manner, involving alternating epithelioneural and neuroepithelial synapses (Bone, Anderson & Pulsford, 1980; Anderson & Bone, 1980). The OSP system of the oozooid generation is less well understood, although it is known that OSPs in the outer epithelium of the oozooid propagate into the stolon, where they have been studied by Anderson (1979). This paper shows that oozooids possess a similar system of neuroepithelial synapses to that of blastozooids, and that these ‘ drive’ OSPs in the same way as occurs during the regenerative transmission of OSPs along the blastozooid chain.

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Communication between individuals in salp chains. II. Physiology

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1980.0153 ◽

1980 ◽

Vol 210 (1181) ◽

pp. 559-574 ◽

Cited By ~ 27

Keyword(s):

Action Potentials ◽

Synaptic Activity ◽

The Other ◽

Reverse Direction ◽

Sensory Cells ◽

Outer Skin ◽

Chemical Synapses ◽

The Brain ◽

Stimulation Of

When stimulated, salp chains achieve rapid coordinated changes in locomotion by the spread of epithelial action potentials or outer skin pulses (o. s. ps) from one zooid to the next along the chain. This process involves alternating epithelioneural and neuroepithelial chemical synapses. Each zooid is linked to another in the chain by two asymmetric attachment plaques; these are polarized so that transmission of o. s. ps proceeds from one zooid to the next in one direction at one plaque, and in the reverse direction at the other plaque. Sensory cells at the plaques send axons to the brain; they are not electrically coupled to the conducting epithelium in which they lie. Input from the plaque sensory cells affects the swimming generator in the brain (causing locomotor changes) and evokes synaptic activity at neuroepithelial synapses around the brain. This gives rise to o. s. ps that are conducted around the whole of the outer epithelium of the zooid and are detected at the plaques by the sensory cells of adjacent zooids. Severe stimulation of a zooid in the chain induces all zooids to separate; possible mechanisms of separation are discussed.

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