This review is focused on purinergic neurotransmission, i.e., ATP released from nerves as a transmitter or cotransmitter to act as an extracellular signaling molecule on both pre- and postjunctional membranes at neuroeffector junctions and synapses, as well as acting as a trophic factor during development and regeneration. Emphasis is placed on the physiology and pathophysiology of ATP, but extracellular roles of its breakdown product, adenosine, are also considered because of their intimate interactions. The early history of the involvement of ATP in autonomic and skeletal neuromuscular transmission and in activities in the central nervous system and ganglia is reviewed. Brief background information is given about the identification of receptor subtypes for purines and pyrimidines and about ATP storage, release, and ectoenzymatic breakdown. Evidence that ATP is a cotransmitter in most, if not all, peripheral and central neurons is presented, as well as full accounts of neurotransmission and neuromodulation in autonomic and sensory ganglia and in the brain and spinal cord. There is coverage of neuron-glia interactions and of purinergic neuroeffector transmission to nonmuscular cells. To establish the primitive and widespread nature of purinergic neurotransmission, both the ontogeny and phylogeny of purinergic signaling are considered. Finally, the pathophysiology of purinergic neurotransmission in both peripheral and central nervous systems is reviewed, and speculations are made about future developments.

/pdf/physiology-and-pathophysiology-of-purinergic-1z94g2hz0f.pdf

Physiology and Pathophysiology of Purinergic Neurotransmission

In understanding how visual signals function, quantifying the components of those patterns is vital. With the ever- increasing power and availability of digital photography, many studies are utilizing this technique to study the con- tent of animal colour signals. Digital photography has many advantages over other techniques, such as spectrometry, for measuring chromatic information, particularly in terms of the speed of data acquisition and its relatively cheap cost. Not only do digital photographs provide a method of quantifying the chromatic and achromatic content of spa- tially complex markings, but also they can be incorporated into powerful models of animal vision. Unfortunately, many studies utilizing digital photography appear to be unaware of several crucial issues involved in the acquisition of images, notably the nonlinearity of many cameras' responses to light intensity, and biases in a camera's processing of the images towards particular wavebands. In the present study, we set out step-by-step guidelines for the use of digital photography to obtain accurate data, either independent of any particular visual system (such as reflection values), or for particular models of nonhuman visual processing (such as that of a passerine bird). These guidelines include how to: (1) linearize the camera's response to changes in light intensity; (2) equalize the different colour channels to obtain reflectance information; and (3) produce a mapping from camera colour space to that of another colour space (such as photon catches for the cone types of a specific animal species). © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 90 , 211-237. ADDITIONAL KEYWORDS: camera calibration - colour vision - colour measurement - digital cameras - imaging - radiance - reflection - signals.

http://www.cvc.uab.es/~aparraga/Publications/Stevens_et_al_BJLinnSoc()2007.pdf

Using digital photography to study animal coloration

Vanecek, Jiri. Cellular Mechanisms of Melatonin Action. Physiol. Rev. 78: 687–721, 1998. — The pineal hormone melatonin is involved in photic regulations of various kinds, including adaptation to l...

Cellular Mechanisms of Melatonin Action

This review gives an overview of recent advances in the potential applications of superhydrophobic materials. Such properties are characterized by extremely high water contact angles and various adhesion properties. The conception of superhydrophobic materials has been possible by studying and mimicking natural surfaces. Now, various applications have emerged such as anti-icing, anti-corrosion and anti-bacterial coatings, microfluidic devices, textiles, oil–water separation, water desalination/purification, optical devices, sensors, batteries and catalysts. At least two parameters were found to be very important for many applications: the presence of air on superhydrophobic materials with self-cleaning properties (Cassie–Baxter state) and the robustness of the superhydrophobic properties (stability of the Cassie–Baxter state). This review will allow researchers to envisage new ideas and industrialists to advance in the commercialization of these materials.

Recent advances in the potential applications of bioinspired superhydrophobic materials

Trophic effects of purines in neurons and glial cells.

Chromatophores, including melanophores, xanthophores, erythrophores, leucophores and iridophores, are responsible for the revelation of integumentary coloration in fish. Recently, blue chromatophores, also called cyanophores, were added to the list of chromatophores. Many of them are also known to possess cellular motility, by which fish are able to change their integumentary hues and patterns, thus enabling them to execute remarkable or subtle chromatic adaptation to environmental hues and patterns, and to cope with various ethological encounters. Such physiological color changes are indeed crucial for them to survive, either by protecting themselves from predators or by increasing their chances of feeding. Sometimes, they are also useful in courtship and mutual communications among individuals of the same species, leading to an increased rate of species survival. Such strategies are realized by complex mechanisms existing in the endocrine and/or nervous systems. Current studies further indicate that some paracrine factors such as endothelins (ETs) are involved in these processes. In this review, the elaborate mechanisms regulating chromatophores in these lovely aquatic animals are described.

The regulation of motile activity in fish chromatophores.

Publisher Summary This chapter discusses cytophysiology of fish chromatophores, with emphasis on the chromatophores of class Osteichthyes. The chromatophores are responsible not only for the generation of color but also for changes in coloration of the surface coat. The beautiful colors and patterns and the spectacular changes in coloration is considered an important phenomena as it provides protection and assist in the survival of species in their habitats. Many poikilothermic aquatic animals, including fishes, use chromatic changes as a means of visual communication. The chapter highlights “physiological color changes,” which are the rapid changes caused by the motile activities of chromatophores. The absorption of light by the pigment in poikilothermic vertebrates is achieved by the light absorbing chromatophores, which include the melanophores, the erythrophores, and the xanthophores and also by the scattering and the reflection of light by intracellular structures, in the absence of colored materials, dependent on the presence in the skin of the light-reflecting chromatophores—namely, the leucophores and the iridophores. In the integument of fishes, pigment cells are found mostly in the dermis, where all the varieties of chromatophores can be located.

Cytophysiology of fish chromatophores

Control of chromatophore movements in teleost fishes

Receptor mechanisms in fish chromatophores-I. Alpha nature of adrenoceptors mediating melanosome aggregation in guppy melanophores.

Dendritic chromatophores that contained blue pigmentary organelles were found in the bluish parts of the skin of two callionymid species, the mandarin fish, Synchiropus splendidus, and the psychedelic fish, S. picturatus. We named these novel cells “cyanophores” and the organelles “cyanosomes”. In response to various stimulatory cues, the cyanophores responded by the aggregation or dispersion of cyanosomes. In addition to their role in the revelation of bluish hues, these cyanophores may participate in the changes in shades of blue of these gorgeous fish.

https://bioone.org/journals/zoological-science/volume-12/issue-6/zsj.12.811/Blue-Chromatophores-in-Two-Species-of-Callionymid-Fish/10.2108/zsj.12.811.pdf

Ryozo Fujii

Papers

The regulation of motile activity in fish chromatophores.

Cytophysiology of fish chromatophores

Control of chromatophore movements in teleost fishes

Receptor mechanisms in fish chromatophores-I. Alpha nature of adrenoceptors mediating melanosome aggregation in guppy melanophores.

Blue Chromatophores in Two Species of Callionymid Fish