Separate effects of a classical conditioning procedure on respiratory pumping, swimming, and inking in Aplysia fasciata.
We examined whether swimming and inking, two defensive responses in Aplysia fasciata, are facilitated by a classical conditioning procedure that has been shown to facilitate a third defensive response, respiratory pumping. Training consisted of pairing a head shock (UCS) with a modified seawater (85%, 120%, or pH 7.0 seawater--CSs). Animals were tested by re-exposing them to the same altered seawater 1 hr after the training. For all three altered seawaters, only respiratory pumping is specifically increased by conditioning. Swimming is sensitized by shock, and inking is unaffected by training, indicating that the conditioning procedure is likely to affect a neural site that differentially controls respiratory pumping. Additional observations also indicate that the three defensive responses are differentially regulated. First, different noxious stimuli preferentially elicit different defensive responses. Second, the three defensive responses are differentially affected by shock. Inking is elicited only immediately following shock, whereas swimming and respiratory pumping are facilitated for a period of time following the shock. Third, swimming and respiratory pumping are differentially affected by noxious stimuli that are delivered in open versus closed environments. These data confirm that neural pathways exist that allow Aplysia to modulate separately each of the three defensive behaviors that were examined. (+info)
Nonadrenergic innervation of the rat laryngeal vasculature.
In order to gain a better understanding of the central and local control of laryngeal blood flow, the vascular innervation to the rat laryngeal muscles was examined. To visualize the vascular network, the animals were perfused with a gelatin/India ink solution. The larynges were removed and fixed. The superior laryngeal, cricothyroid, and inferior laryngeal arteries (all branch off the superior thyroid artery) were dissected in continuity into their respective muscles. Specimens were reacted in toto using immunohistochemical techniques for the presence of neuropeptide-Y (NPY), vasoactive intestinal peptide (VIP), calcitonin gene related peptide (CGRP), and neuronal nitric oxide synthase (NOS-1). Results show that all of the laryngeal vasculature is richly innervated by fibers containing these peptides. Qualitatively, the most prominent of these is NPY in association with the superior and the inferior laryngeal arteries, followed by VIP and NOS-1, and finally CGRP distributed equally on all the vessels. Immunopositive fibers are found along the entire course of the feeding arteries, beginning with the superior thyroid artery and continuing down to small arterioles into the terminal vascular beds. These peptides can act as vasodilators, vasoconstrictors, and/or neuromodulators and may work synergistically or antagonistically with other transmitters in controlling laryngeal blood flow. Their effects are dependent on the specific vascular bed in question, that is, in some areas they are vasodilators, in others vasoconstrictors, and in other neuromodulators. What effects they have on the laryngeal vasculature and how they interact within the larynx have yet to be determined. (+info)
Intact omentum for ocular vascularization.
Twenty dogs had their intact omentum extensively lengthened by a series of surgical maneuvers. Transverse incisions were then made along the chest, shoulder, neck, and scalp which were undermined and connected to form a subcutaneous tunnel through which the omentum was brought up to the orbit. The lateral rectus muscle of the eye was divided and a scaleral flap developed along the lateral superior region of the eye which exposed the choroid upon which the omentum was secured. Subsequent studies demonstrated vascular connections between intraocular vessels and those of the omentum. Proof of the existence of these vascular connections was based upon fluorescent funduscopic, gross, and histologic evidence. (+info)
The development and mature organisation of the end-artery retinal vasculature in a marsupial, the dunnart Sminthopsis crassicaudata.
The end-artery retinal vasculature of a marsupial, the fat-tailed dunnart, was defined by India ink injection and studied in wholemounts. In the adult, the vitreal vasculature supplying the ganglion-cell layer has major paired-vessels in a horizontal H shape. These vessels skirt the area centralis and visual streak that are supplied by fine end-loops. A second vascular layer of uniformly distributed endloops arises from the superficial vessels and lies at the inner nuclear/outer plexiform border. During development, vessels enter the eye via the optic nerve head to form the upper vasculature, assuming an essentially mature arrangement prior to the formation of the area centralis and visual streak. Vessels then descend to form the lower bed. Unlike the cat, the dunnart has retinal vessels that are patent throughout development, their growth is interstitial and reductive remodelling is not seen. A retinal end-artery system may have evolved in marsupials because their precocity requires a vasculature that is functional from early stages of development. (+info)
Corneal tattooing: an alternative treatment for disfiguring corneal scars.
BACKGROUND: The performance and results of corneal tattooing are described in a case series of 11 patients suffering from a disfiguring corneal scar using a technique similar to conventional dermatography. METHODS: Drawing ink in different shades was applied into the anterior corneal stroma by punctures performed with a conventional spatula needle. RESULTS: Up to 4 years after surgery all patients still had satisfactory staining of the formerly cosmetically disfiguring corneal scar. CONCLUSION: Tattooing of unsightly corneal scars proved to be an efficient and easy to perform technique, yielding acceptable results during follow up. (+info)
Making your mark again in surgery.
Accurate, durable pre-operative skin marking that withstands the necessary vigorous surgical skin preparation on the theatre table minimises confusion and the risk of mistakes occurring perioperatively, as well as assisting the surgeon with the technicalities of required skin incisions. Felt-tipped marker pens vary widely in achieving these objectives. A selection of markers, including a number used by junior surgical staff on the wards, was investigated. (+info)
PATHWAYS FOR BIOSYNTHESIS OF A BACTERIAL CAPSULAR POLYSACCHARIDE. IV. CAPSULE RESYNTHESIS BY DECAPSULATED RESTING-CELL SUSPENSIONS.
Juni, Elliot (Emory University, Atlanta, Ga.), and Gloria A. Heym. Pathways for biosynthesis of a bacterial capsular polysaccharide. IV. Capsule resynthesis by decapsulated resting-cell suspensions. J. Bacteriol. 87:461-467. 1964.-Methods were devised for stripping capsules from encapsulated bacteria. By use of stripped resting-cell suspensions of a gram-negative capsule-forming coccus, it was shown that polysaccharide capsule resynthesis depends upon the presence of air and an oxidizable substrate. Capsule resynthesis proceeds linearly with time. For a given quantity of stripped cells, the net amount of polysaccharide capsule synthesized is a linear function of the amount of substrate oxidized. The only factor that appears to limit the extent of capsule synthesis by resting cells is the amount of substrate utilized. A series of photomicrographs of wet mounts made in India ink show the appearance of stripped cells and resynthesized capsules formed during oxidation of pyruvate and glucose by stripped resting-cell suspensions. (+info)
Vascular supplies differ in regenerating and nonregenerating amputated rodent digits.
Bone regenerates following amputation through the level of the nail, but bone is capped following amputation through more proximal levels. Because osteogenesis requires an ample blood supply, we postulated that a restricted vascular supply might be correlated with restricted regenerative ability at proximal levels. More than 40 rats and mice were injected with ink or resin to visualize vascular supplies of intact, regenerating, and nonregenerating rat and mouse digits. Ink-injected specimens were viewed as histological sections or cleared whole mounts. Partially digested resin casts were viewed using scanning electron microscopy. Contrary to our hypothesis, prior to amputation, proximal sites are more vascular than distal sites. At both proximal and distal levels, endosteal and periosteal vascular systems are evident. However, in proximal phalanges, additional subcutaneous and dermal layers encircle the bone. Beneath the distal nail, these layers are absent, and a single layer of vessels provides both periosteal and cutaneous supplies. After amputation at both levels, new vessels sprout profusely in osteogenic areas of both endosteum and periosteum. However, at proximal levels, the additional hypodermal and dermal vessels contribute to a vascular plexus that, paradoxically, may impair bone regrowth by contributing to the formation of dermal scar rather than bone. (+info)