scholarly journals Differential visual depth discrimination of hooded as compared to albino rats

1969 ◽  
Vol 14 (5) ◽  
pp. 207-208 ◽  
Author(s):  
Philip W. Davidson ◽  
Richard D. Walk
1964 ◽  
Vol 19 (2) ◽  
pp. 423-426 ◽  
Author(s):  
Doris C. Dehardt ◽  
David L. Whitney

On an open visual cliff rats significantly preferred the shallow side while on an otherwise comparable closed cliff they did not, suggesting either that depth discrimination is enhanced by the additional information provided by the deep side of the open model, or that animals merely avoided the large open area of the deep side. The latter suggests that side preferences in open model cliffs are not necessarily valid indicators of visual depth discriminability in rats. Texture density was not a sufficient cue for depth discriminability as indicated by the preference of Ss for 1-in. checks in both 3-in. vs 1-in. and 1-in. vs ¼-in. comparison tests.


1962 ◽  
Vol 59 (6) ◽  
pp. 489-501 ◽  
Author(s):  
Paul G. Shinkman

1972 ◽  
Vol 30 (2) ◽  
pp. 427-433
Author(s):  
Sachio Ashida

64 male hooded rats were tested on a visual depth discrimination task in a modified Lashley Jumping Stand. The monocular Ss ( n = 32) were operated upon to close either the left or right eye and the control Ss ( n = 32) were sham operated. There were no significant differences in jumping performance between the binocular and the monocular Ss although the task was facilitated for both groups when a visual depth was increased. However, the monocular Ss showed significant orienting responses toward the “unoperated” side before they jumped. The results suggest that motion parallax overcomes both monocular and binocular visual weakness in a jumping-stand discrimination situation.


Author(s):  
G. Mazzocchi ◽  
P. Rebuffat ◽  
C. Robba ◽  
P. Vassanelli ◽  
G. G. Nussdorfer

It is well known that the rat adrenal zona glomerulosa steroidogenic activity is controlled by the renin-angiotensin system. The ultrastructural changes in the rat zona glomerulosa cells induced by renovascular hypertension were described previously, but as far as we are aware no correlated biochemical and morphometric investigations were performed.Twenty adult male albino rats were divided into 2 experimental groups. One group was subjected to restriction of blood flow to the left kidney by the application of a silver clip about the left renal artery. The other group was sham-operated and served as a control. Renovascular hypertension developed in about 10 days: sistolic blood pressure averaged 165 ± 6. 4 mmHg, whereas it was about 110 ± 3. 8 mmHg in the control animals. The hypertensive and control rats were sacrificed 20 days after the operation. The blood was collected and plasma renin activity was determined by radioimmunological methods. The aldosterone concentration was radioimmunologically assayed both in the plasma and in the homogenate of the left capsular adrenal gland.


Author(s):  
Alfredo Feria-Velasco ◽  
Guadalupe Tapia-Arizmendi

The fine structure of the Harderian gland has been described in some animal species (hamster, rabbit, mouse, domestic fowl and albino rats). There are only two reports in the literature dealing on the ultrastructure of rat Harderian gland in adult animals. In one of them the author describes the myoepithelial cells in methacrylate-embbeded tissue, and the other deals with the maturation of the acinar cells and the formation of the secretory droplets. The aim of the present work is to analize the relationships among the acinar cell components and to describe the two types of cells located at the perifery of the acini.


Author(s):  
R. P. Becker ◽  
J. J. Wolosewick ◽  
J. Ross-Stanton

Methodology has been introduced recently which allows transmission and scanning electron microscopy of cell fine structure in semi-thin sections unencumbered by an embedding medium. Images obtained from these “resinless” sections show a three-dimensional lattice of microtrabeculfee contiguous with cytoskeletal structures and membrane-bounded cell organelles. Visualization of these structures, especially of the matiiDra-nous components, can be facilitated by employing tannic acid in the fixation step and dessicator drying, as reported here.Albino rats were fixed by vascular perfusion with 2% glutaraldehyde or 1.5% depolymerized paraformaldehyde plus 2.5% glutaraldehyde in 0.1M sodium cacodylate (pH 7.4). Tissues were removed and minced in the fixative and stored overnight in fixative containing 4% tannic acid. The tissues were rinsed in buffer (0.2M cacodylate), exposed to 1% buffered osmium tetroxide, dehydrated in ethyl alcohol, and embedded in pure polyethylene glycol-6000 (PEG). Sections were cut on glass knives with a Sorvall MT-1 microtome and mounted onto poly-L-lysine, formvar-carbon coated grids while submerged in a solution of 95% ethanol containing 5% PEG.


Author(s):  
W. Lin ◽  
J. Gregorio ◽  
T.J. Holmes ◽  
D. H. Szarowski ◽  
J.N. Turner

A low-light level video microscope with long working distance objective lenses has been built as part of our integrated three-dimensional (3-D) light microscopy workstation (Fig. 1). It allows the observation of living specimens under sufficiently low light illumination that no significant photobleaching or alternation of specimen physiology is produced. The improved image quality, depth discrimination and 3-D reconstruction provides a versatile intermediate resolution system that replaces the commonly used dissection microscope for initial image recording and positioning of microelectrodes for neurobiology. A 3-D image is displayed on-line to guide the execution of complex experiments. An image composed of 40 optical sections requires 7 minutes to process and display a stereo pair.The low-light level video microscope utilizes long working distance objective lenses from Mitutoyo (10X, 0.28NA, 37 mm working distance; 20X, 0.42NA, 20 mm working distance; 50X, 0.42NA, 20 mm working distance). They provide enough working distance to allow the placement of microelectrodes in the specimen.


Sign in / Sign up

Export Citation Format

Share Document