scholarly journals Sensory system evolution at the origin of craniates

2000 ◽  
Vol 355 (1401) ◽  
pp. 1309-1313 ◽  
Author(s):  
Ann B. Butler
Keyword(s):  
Visual System ◽  
Neural Crest ◽  
Sensory System ◽  
Sensory Systems ◽  
Visual Pathways ◽  
Circumstantial Evidence ◽  
System Evolution ◽  
Multiple Events ◽  
Restricted Distribution ◽  
The Brain

The multiple events at the transition from non–craniate invertebrate ancestors to craniates included the gain and/or elaboration of migratory neural crest and neurogenic placodes. These tissues give rise to the peripherally located, bipolar neurons of all non–visual sensory systems. The brain was also elaborated at or about this same time. Were the peripheral and central events simultaneous or sequential? A serial transformation hypothesis postulates that paired eyes and an enlarged brain evolved before the elaboration of migratory neural crest–placodal sensory systems. Circumstantial evidence for this scenario is derived from the independent occurrence of the combination of large, paired eyes plus a large, elaborated brain in at least three taxa (cephalochordates, arthropods and craniates) and partly from the exclusivity of the diencephalon for visual system–related distal sensory components versus the restricted distribution of migratory neural crest–placodal sensory systems to the remaining parts of the neuraxis. This scenario accounts for the similarity of all central sensory system pathways due to the primary establishment of descending visual pathways via the diencephalon and midbrain tectum to brainstem motor regions and the subsequent exploitation of the same central beachhead by the migratory neural crest–placodal systems as a template for their organization.

Author response for "The brain of the African wild dog. IV . The visual system"

2020 ◽  
Author(s):  
Samson Chengetanai ◽  
Adhil Bhagwandin ◽  
Mads F. Bertelsen ◽  
Therese Hård ◽  
Patrick R. Hof ◽  
...  
Keyword(s):  
Visual System ◽  
Author Response ◽  
African Wild Dog ◽  
Wild Dog ◽  
The Brain

Neuro-Optometric Treatment of Complications from a Cerebellar Astrocytoma

2020 ◽  
pp. 304-312
Keyword(s):  
Visual System ◽  
Common Site ◽  
Us Army ◽  
Cranial Nerve Palsies ◽  
Pilocytic Astrocytomas ◽  
The Us ◽  
Extent Of Damage ◽  
Functional Components ◽  
The Brain

Background: Insult to the brain, whether from trauma or other etiologies, can have a devastating effect on an individual. Symptoms can be many and varied, depending on the location and extent of damage. This presentation can be a challenge to the optometrist charged with treating the sequelae of this event as multiple functional components of the visual system can be affected. Case Report: This paper describes the diagnosis and subsequent ophthalmic management of an acquired brain injury in a 22 year old male on active duty in the US Army. After developing acute neurological symptoms, the patient was diagnosed with a pilocytic astrocytoma of the cerebellum. Emergent neurosurgery to treat the neoplasm resulted in iatrogenic cranial nerve palsies and a hemispheric syndrome. Over the next 18 months, he was managed by a series of providers, including a strabismus surgeon, until presenting to our clinic. Lenses, prism, and in-office and out-of-office neurooptometric rehabilitation therapy were utilized to improve his functioning and make progress towards his goals. Conclusions: Pilocytic astrocytomas are the most common primary brain tumors, and the vast majority are benign with excellent surgical prognosis. Although the most common site is the cerebellum, the visual pathway is also frequently affected. If the eye or visual system is affected, optometrists have the ability to drastically improve quality of life with neuro-optometric rehabilitation.

scholarly journals Neurophysiology goes wild: from exploring sensory coding in sound proof rooms to natural environments

2021 ◽  
Vol 207 (3) ◽  
pp. 303-319
Author(s):  
Heiner Römer
Keyword(s):  
Sensory System ◽  
Sensory Systems ◽  
Natural Environments ◽  
Sensory Coding ◽  
Noise Levels ◽  
Sensory Physiology ◽  
Sound Localisation ◽  
Physical Environments ◽  
History Of ◽  
Adaptive Behaviours

AbstractTo perform adaptive behaviours, animals have to establish a representation of the physical “outside” world. How these representations are created by sensory systems is a central issue in sensory physiology. This review addresses the history of experimental approaches toward ideas about sensory coding, using the relatively simple auditory system of acoustic insects. I will discuss the empirical evidence in support of Barlow’s “efficient coding hypothesis”, which argues that the coding properties of neurons undergo specific adaptations that allow insects to detect biologically important acoustic stimuli. This hypothesis opposes the view that the sensory systems of receivers are biased as a result of their phylogeny, which finally determine whether a sound stimulus elicits a behavioural response. Acoustic signals are often transmitted over considerable distances in complex physical environments with high noise levels, resulting in degradation of the temporal pattern of stimuli, unpredictable attenuation, reduced signal-to-noise levels, and degradation of cues used for sound localisation. Thus, a more naturalistic view of sensory coding must be taken, since the signals as broadcast by signallers are rarely equivalent to the effective stimuli encoded by the sensory system of receivers. The consequences of the environmental conditions for sensory coding are discussed.

scholarly journals Visual pathways in the brain of the jumping spider Marpissa muscosa

2020 ◽  
Vol 528 (11) ◽  
pp. 1883-1902
Author(s):  
Philip O. M. Steinhoff ◽  
Gabriele Uhl ◽  
Steffen Harzsch ◽  
Andy Sombke
Keyword(s):  
Visual Pathways ◽  
Jumping Spider ◽  
The Brain

Role of the neural crest in development of the trabeculae and branchial arches in embryonic sea lamprey, Petromyzon marinus (L)

Development ◽  
1988 ◽  
Vol 102 (2) ◽  
pp. 301-310 ◽  
Author(s):  
R.M. Langille ◽  
B.K. Hall
Keyword(s):  
Neural Crest ◽  
Skeletal Development ◽  
Petromyzon Marinus ◽  
Branchial Arches ◽  
Artificial Fertilization ◽  
Vertebrate Skeleton ◽  
The Brain ◽  
Head Skeleton ◽  
Neurula Stage

Lamprey embryos were obtained by artificial fertilization to ascertain the contributions made by the neural crest to the head skeleton. Early-neurula-stage embryos of Petromyzon marinus were subjected to neural crest extirpation along the anterior half from one of seven zones, raised to a larval stage at which control larvae exhibit well-developed skeletons and analysed by light microscopy for any abnormalities to the cranial and visceral skeleton. The removal of premigratory neural crest at the level of the anterior prosencephalon (zone I) and at the level of somites 6 to 8 (zone VII) had no effect on skeletal development. However, the extirpation of neural crest from the intervening regions was positively correlated with deletions/reductions to the trabeculae (basicranial elements) and to the branchial arches (viscerocranial elements). Alterations to the trabeculae (16/27 cases, or 59%) occurred only after extirpation of zones II-V (corresponding to the posterior prosencephalon to midrhombencephalon) while alterations to the branchial arches (21/28 cases, or 75%) occurred only after removal of neural crest from zones III-VI (corresponding to the mesencephalon to the level of the fifth somite). Furthermore, the first three branchial arches were correlated in a majority of cases with neural crest from zone III, the next two arches with zones IV, V and VI and the last two arches with zone VI. Organs that develop within or adjacent to the area of neural crest extirpation such as the brain, notochord and lateral mesodermal derivatives were not affected. Parachordals were never altered by the operations nor were there any discernible changes to developing mucocartilage or to the prechondrogenic otic capsule. The contributions of the neural crest to the petromyzonid head skeleton described herein are compared with the roles of neural crest in the development of cranial and visceral skeletal elements in other vertebrates. The importance of these findings to the current hypothesis of the phylogeny of the vertebrate skeleton and the central role of the neural crest in vertebrate cephalization is discussed.

Jaw and branchial arch mutants in zebrafish I: branchial arches

Development ◽  
1996 ◽  
Vol 123 (1) ◽  
pp. 329-344 ◽  
Author(s):  
T.F. Schilling ◽  
T. Piotrowski ◽  
H. Grandel ◽  
M. Brand ◽  
C.P. Heisenberg ◽  
...  
Keyword(s):  
Neural Crest ◽  
Zebrafish Embryo ◽  
Neural Crest Cells ◽  
Branchial Arch ◽  
Pigment Cells ◽  
Pharyngeal Arches ◽  
Pectoral Fins ◽  
Branchial Arches ◽  
Group Members ◽  
The Brain

Jaws and branchial arches together are a basic, segmented feature of the vertebrate head. Seven arches develop in the zebrafish embryo (Danio rerio), derived largely from neural crest cells that form the cartilaginous skeleton. In this and the following paper we describe the phenotypes of 109 arch mutants, focusing here on three classes that affect the posterior pharyngeal arches, including the hyoid and five gill-bearing arches. In lockjaw, the hyoid arch is strongly reduced and subsets of branchial arches do not develop. Mutants of a large second class, designated the flathead group, lack several adjacent branchial arches and their associated cartilages. Five alleles at the flathead locus all lead to larvae that lack arches 4–6. Among 34 other flathead group members complementation tests are incomplete, but at least six unique phenotypes can be distinguished. These all delete continuous stretches of adjacent branchial arches and unpaired cartilages in the ventral midline. Many show cell death in the midbrain, from which some neural crest precursors of the arches originate. lockjaw and a few mutants in the flathead group, including pistachio, affect both jaw cartilage and pigmentation, reflecting essential functions of these genes in at least two neural crest lineages. Mutants of a third class, including boxer, dackel and pincher, affect pectoral fins and axonal trajectories in the brain, as well as the arches. Their skeletal phenotypes suggest that they disrupt cartilage morphogenesis in all arches. Our results suggest that there are sets of genes that: (1) specify neural crest cells in groups of adjacent head segments, and (2) function in common genetic pathways in a variety of tissues including the brain, pectoral fins and pigment cells as well as pharyngeal arches.

scholarly journals THE VISUAL SYSTEM: A "CHICKEN AND EGG" PROBLEM SOLVED

2009 ◽  
Vol 05 (01) ◽  
pp. 115-121
Author(s):  
ANDREW R. PARKER ◽  
H. JOHN CAULFIELD
Keyword(s):  
Visual System ◽  
Neural Plasticity ◽  
Neural Circuit ◽  
Process Data ◽  
System A ◽  
New Information ◽  
The Brain

"What comes first: the chicken or the egg?" Eyes and vision were a great concern for Darwin. Recently, religious fundamentalists have started to attack evolution on the grounds that this is a chicken and egg problem. How could eyes improve without the brain module to use the new information that eye provides? But how could the brain evolve a neural circuit to process data not available to it until a new eye capability emerges? We argue that neural plasticity in the brain allows it to make use of essentially any useful information the eye can produce. And it does so easily within the animal's lifetime. Richard Gregory suggested something like this 40 years ago. Our work resolves a problem with his otherwise-insightful work.

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