The commensal association of Calliactis polypus and the hermit crab Dardanus gemmatus in Hawaii

1970 ◽  
Vol 48 (2) ◽  
pp. 351-357 ◽  
Author(s):  
D. M. Ross
Keyword(s):  
Nervous System ◽  
Small Area ◽  
Behavior Pattern ◽  
Mechanical Stimuli ◽  
Closely Related Species ◽  
Active Behavior ◽  
Highly Active ◽  
Hawaiian Species ◽  
The Pacific ◽  
Pedal Disc

Calliactis polypus (Forskål) lives as a commensal with various pagurids in the Pacific and Indian Oceans. In trials with the Hawaiian species, Dardanus gemmatus, the anemone, unlike the European C. parasitica, displayed only slight activity towards crabs or molluscan shells. As reported previously, crabs display a highly active behavior pattern towards C. polypus, tapping and scratching the column and eventually transferring it to its shell. The mechanical stimuli applied by the crab cause C. polypus to relax so completely that it can be lifted easily off the surface to which it was attached. Unlike C. parasitica and C. tricolor under similar circumstances, C. polypus does not release its pedal disc unaided. The tentacles and pedal disc of the detached C. polypus are extremely sticky and adhere at once to any solid surface presented to them. This enables an anemone detached by a crab to settle quickly on the shell even when only a small area of the pedal disc or only a few tentacles come into contact with the shell when placed there by the crab. The discussion emphasizes these differences in the behavior of closely related species in achieving the same ends. It also stresses that C. polypus, possessing a relatively simple nervous system, displays an impressive repertoire of responses to specific stimuli in its association with its pagurid host.

Neuro-AIDS: Current status and Challenges to Antiretroviral Drug Therapy (ART) for Its Treatment.

2020 ◽  
Vol 15 ◽  
Author(s):  
Smita P. Kakad ◽  
Sanjay J. Kshirsagar
Keyword(s):  
Nervous System ◽  
Antiretroviral Therapy ◽  
Highly Active Antiretroviral Therapy ◽  
Sensory Neuropathy ◽  
Current Status ◽  
Viral Reservoir ◽  
Viral Reservoirs ◽  
Highly Active ◽  
Aids Therapy ◽  
The Brain

Introduction: The infiltration of HIV into the brain alters the functions of the nervous system known as NeuroAIDS. It leads to neuronal defects clinically manifested by motor and cognitive dysfunctions. Materials/Methods: Current antiretroviral therapy can prevent viral replication but cannot cure the disease completely. HAART-Highly active antiretroviral therapy used for the treatment of HIV infection. Challenges in neuro-AIDS therapy are as shown in the graphical abstract. One of the challenges is latent viral reservoirs like the brain; which acts as a sanctuary site for viruses. Nearly ~50% of HIV patients show neuropathological signs. Nervous system related disorders including AIDS dementia, sensory neuropathy, and myelopathy have a 25% of prevalence in patients having access to a highly active combination antiretroviral therapy. Results/Conclusions: Brain is one of the viral sanctuary sites for HIV. The current need of neuro-AIDS therapy is to target the brain as a viral reservoir. Drugs should cross or bypass the blood-brain barrier to reach the brain with effective concentrations. Current research on novel drug delivery approaches may prove helpful to treat neuro-AIDS and related disorders effectively.

Efavirenz-induced neurological symptoms in rare homozygote CYP2B6 *2/*2 (C64T)

2007 ◽  
Vol 18 (8) ◽  
pp. 575-576 ◽  
Author(s):  
Osamu Usami ◽  
Yugo Ashino ◽  
Yuichi Komaki ◽  
Masafumi Tomaki ◽  
Toshiya Irokawa ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cytochrome P450 ◽  
Plasma Concentrations ◽  
Highly Active ◽  
P450 Isozymes ◽  
Cytochrome P450 Isozymes ◽  
Hiv 1 ◽  
Rare Homozygote ◽  
Hepatic Cytochrome

Some of the HIV-1-infected patients who were given highly active anti-retroviral therapy (HAART) including efavirenz (EFV) presented adverse central nervous system (CNS) symptoms such as fatigue and insomnia. The incidence of adverse CNS symptoms is associated with hepatic cytochrome P450 isozymes (CYP2B6) polymorphisms. For example, CYP2B6 *6 (G516T and A785G) and *7 (G516T, A785G and C1459T) prolonged the EFV half-life despite discontinuation of EFV. CYP2B6 *2/*2 (C64T) is extremely rare and there have been no data describing the EFV plasma concentrations in C64T homozygous patients, who developed adverse CNS symptoms. C64T homozygous possibly has some catalytic defects.

Clinical study of fetal neurobehavior by the KANET test

2018 ◽  
Vol 46 (6) ◽  
pp. 631-639
Author(s):  
Raul Moreira Neto ◽  
Selma Porovic
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Prenatal Diagnosis ◽  
Behavior Pattern ◽  
Review Of Literature ◽  
Fetal Medicine ◽  
Morphological Studies ◽  
4D Ultrasound ◽  
Spontaneous Movements

AbstractFetal neurology is evolving as an area of great interest in prenatal diagnosis and fetal medicine. The identification and diagnosis of brain damage prenatally has been a great challenge in obstetrics for many years. Investigations of fetal behavior in comparison with morphological studies led to the conclusion that fetal behavioral patterns directly reflect developmental and maturational processes of the fetal central nervous system (CNS). Four-dimensional (4D) ultrasound has greatly improved the assessment of the quality of the fetal spontaneous movements, and enabled a better evaluation of fetal behavior. The assessment of normal neurobehavioral development by 4D ultrasound provided the opportunity to investigate functional characteristics of the fetus that could predict neurological developmental dysfunction. Some studies have already been carried out to evaluate this new methodology in the observation of fetal behavior during different stages of gestation, in an attempt to better understand the relationships between the maturation of the CNS of the fetus and its implications on its behavior pattern. We present a review of literature on fetal behavior by 4D ultrasound.

Leech Mechanosensation

2017 ◽  
Author(s):  
Brian D. Burrell
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Sensory Neurons ◽  
Receptive Fields ◽  
Model Systems ◽  
Sensory Cells ◽  
Mechanical Stimuli ◽  
Nociceptive Neurons ◽  
Mechanosensory Neurons ◽  
The Central Nervous System

The medicinal leech (Hirudo verbana) is an annelid (segmented worm) and one of the classic model systems in neuroscience. It has been used in research for over 50 years and was one of the first animals in which intracellular recordings of mechanosensory neurons were carried out. Remarkably, the leech has three main classes of mechanosensory neurons that exhibit many of the same properties found in vertebrates. The most sensitive of these neurons are the touch cells, which are rapidly adapting neurons that detect low-intensity mechanical stimuli. Next are the pressure cells, which are slow-adapting sensory neurons that respond to higher intensity, sustained mechanostimulation. Finally, there are nociceptive neurons, which have the highest threshold and respond to potentially damaging mechanostimuli, such as a pinch. As observed in mammals, the leech has separate mechanosensitive and polymodal nociceptors, the latter responding to mechanical, thermal, and chemical stimuli. The cell bodies for all three types of mechanosensitive neurons are found in the central nervous system where they are arranged as bilateral pairs. Each neuron extends processes to the skin where they form discrete receptive fields. In the touch and pressure cells, these receptive fields are arranged along the dorsal-ventral axis. For the mechano-only and polymodal nociceptive neurons, the peripheral receptive fields overlap with the mechano-only nociceptor, which also innervates the gut. The leech also has a type of mechanosensitive cell located in the periphery that responds to vibrations in the water and is used, in part, to detect potential prey nearby. In the central nervous system, the touch, pressure, and nociceptive cells all form synaptic connections with a variety of motor neurons, interneurons, and even each other, using glutamate as the neurotransmitter. Synaptic transmission by these cells can be modulated by a variety of activity-dependent processes as well as the influence of neuromodulatory transmitters, such as serotonin. The output of these sensory neurons can also be modulated by conduction block, a process in which action potentials fail to propagate to all the synaptic release sites, decreasing synaptic output. Activity in these sensory neurons leads to the initiation of a number of different motor behaviors involved in locomotion, such as swimming and crawling, as well as behaviors designed to recoil from aversive/noxious stimuli, such as local bending and shortening. In the case of local bending, the leech is able to bend in the appropriate direction away from the offending stimuli. It does so through a combination of which mechanosensory cell receptive fields have been activated and the relative activation of multiple sensory cells decoded by a layer of downstream interneurons.

scholarly journals Vitamin D as a Neuroactive Substance: Review

2006 ◽  
Vol 6 ◽  
pp. 125-139 ◽  
Author(s):  
Stephen J. Kiraly ◽  
Michael A. Kiraly ◽  
Rick D. Hawe ◽  
Naila Makhani
Keyword(s):  
Central Nervous System ◽  
Vitamin D ◽  
Nervous System ◽  
Vitamin D Insufficiency ◽  
Physiological Importance ◽  
Highly Active ◽  
Cochrane Reviews ◽  
Research Bias ◽  
Neuroactive Substance ◽  
The Central Nervous System

The objectives of this paper were (1) to review recent research on the actions of vitamin D as a steroid derivative with neuroactive properties and (2) to highlight clinical relevance and need for more research. Our methods included review of research from current journals, Medline, and Cochrane Reviews; theoretical discussion. Scientific research has had a justifiably strong emphasis on how vitamin D affects calcium metabolism and bone. This appears to have eclipsed its fundamental actions on several other important systems, including the central nervous system. Vitamin D as a neuroactive compound, a prohormone, is highly active in regulating cell differentiation, proliferation, and peroxidation in a variety of structures, including the brain. Vitamin D insufficiency is not rare. Historically, focus has been on bone metabolism, which appears to have causedresearch biasandevidence bias, distorting physiological importance. The central nervous system is increasingly recognized as a target organ for vitamin D via its wide-ranging hormonal effects, including the induction of proteins such as nerve growth factor. We need more research on this important neuroactive substance because it may play a role as a relatively safe and inexpensive pharmaceutical in the prevention and treatment of a number of common neuropsychiatric conditions.

THE RESPONSE TO MOLLUSCAN SHELLS OF THE SWIMMING SEA ANEMONES STOMPHIA COCCINEA AND ACTINOSTOLA NEW SPECIES

1967 ◽  
Vol 45 (6) ◽  
pp. 895-906 ◽  
Author(s):  
D. M. Ross ◽  
L. Sutton
Keyword(s):  
Organic Matter ◽  
New Species ◽  
Behavior Pattern ◽  
Hermit Crabs ◽  
Behavior Patterns ◽  
Sea Anemones ◽  
Modiolus Modiolus ◽  
Calliactis Parasitica ◽  
Main Components ◽  
Pedal Disc

Behavior patterns in the sea anemones Stomphia coccinea and Actinostala new species are described by which these animals settled preferentially on shells of Modiolus modiolus (commensal of S. coccinea) after they have been made to swim in response to the appropriate stimuli (the starfishes Dermasterias or Hippasteria, the nudibranch Aeolidia papillosa, etc.). Tentacular and oral contact without adhesion, followed by great distension of the pedal disc and some flexion of the column towards the shell, were the main components of these behavior patterns. Anemones which had been allowed to settle on other surfaces not more than 6 h previously migrated to shells which were brought into contact with the tentacles. Shells which were boiled in alkali to remove organic matter lost their capacity to elicit the response. This behavior pattern is compared with that of Calliactis parasitica, a commensal of hermit crabs which shows a preference for settling on shells of large gastropods.

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