VASCULARITY OF THE HYPOPHYSIS OF LOWER VERTEBRATES: THE PAINTED TURTLE, CHRYSEMYS PICTA MARGINATA AGASSIZ

1952 ◽  
Vol 30 (2) ◽  
pp. 134-143 ◽  
Author(s):  
Stanley James Taylor
Keyword(s):  
Anterior Lobe ◽  
Chrysemys Picta ◽  
Pars Intermedia ◽  
Painted Turtle ◽  
Fresh Tissue ◽  
Vascular Surface ◽  
Lower Vertebrates ◽  
Pars Nervosa ◽  
The Brain ◽  
Adjacent Brain

Measurements were made on the diameter and length of the capillaries of the turtle hypophysis. The volume and surface of vessels were calculated and compared with those of the cat, frog, and salamander. Only the anterior lobe showed vessels which were significantly wider than in the adjacent brain tissue. The surface area of blood in the anterior and tuberal lobes is very extensive, 17 sq. mm. to 18 sq. mm. for 1 cu. mm. of fresh tissue, and is between two and three times as great as in the other lobes and in the richest centers of the brain. The vascular surface in each lobe, except the intermediate one, is lower than, but shows similar variation to, that of the cat. The pars nervosa is supplied by vessels between it and the pars intermedia as in the salamander and is unlike that of the frog or cat with numerous vessels penetrating its substance.

Proteomic changes in the brain of the western painted turtle (Chrysemys picta bellii ) during exposure to anoxia

PROTEOMICS ◽  
2015 ◽  
Vol 15 (9) ◽  
pp. 1587-1597 ◽  
Author(s):  
Richard W. Smith ◽  
Phil Cash ◽  
David W. Hogg ◽  
Leslie T. Buck
Keyword(s):  
Chrysemys Picta ◽  
Painted Turtle ◽  
Chrysemys Picta Bellii ◽  
The Brain

Permeability of the microcirculation in area postrema of rat

1988 ◽  
Vol 46 ◽  
pp. 348-349
Author(s):  
Shams M. Ghoneim ◽  
Frank M. Faraci ◽  
Gary L. Baumbach
Keyword(s):  
Brain Stem ◽  
Area Postrema ◽  
Upper Body ◽  
Sprague Dawley ◽  
Sodium Cacodylate ◽  
Acute Hypertension ◽  
Sprague Dawley Rats ◽  
Ultrastructural Characteristics ◽  
The Brain ◽  
Adjacent Brain

The area postrema is a circumventricular organ in the brain stem and is one of the regions in the brain that lacks a fully functional blood-brain barrier. Recently, we found that disruption of the microcirculation during acute hypertension is greater in area postrema than in the adjacent brain stem. In contrast, hyperosmolar disruption of the microcirculation is greater in brain stem. The objective of this study was to compare ultrastructural characteristics of the microcirculation in area postrema and adjacent brain stem.We studied 5 Sprague-Dawley rats. Horseradish peroxidase was injected intravenously and allowed to circulate for 1, 5 or 15 minutes. Following perfusion of the upper body with 2.25% glutaraldehyde in 0.1 M sodium cacodylate, the brain stem was removed, embedded in agar, and chopped into 50-70 μm sections with a TC-Sorvall tissue chopper. Sections of brain stem were incubated for 1 hour in a solution of 3,3' diaminobenzidine tetrahydrochloride (0.05%) in 0.05M Tris buffer with 1% H2O2.

Ultrastructural investigation of an adenoma of the pituitary post mortem

1987 ◽  
Vol 45 ◽  
pp. 622-623
Author(s):  
Shirley Siew ◽  
W. C. deMendonca
Keyword(s):  
Deleterious Effect ◽  
Anterior Lobe ◽  
Definitive Diagnosis ◽  
Pars Intermedia ◽  
Post Mortem ◽  
Close Apposition ◽  
Autopsy Material ◽  
Progressive Loss ◽  
Transmission Electron ◽  
Means Of Transmission

The deleterious effect of post mortem degeneration results in a progressive loss of ultrastructural detail. This had led to reluctance (if not refusal) to examine autopsy material by means of transmission electron microscopy. Nevertheless, Johannesen has drawn attention to the fact that a sufficient amount of significant features may be preserved in order to enable the establishment of a definitive diagnosis, even on “graveyard” tissue.Routine histopathology of the autopsy organs of a woman of 78 showed the presence of a well circumscribed adenoma in the anterior lobe of the pituitary. The lesion came into close apposition to the pars intermedia. Its architecture was more compact and less vascular than that of the anterior lobe. However, there was some grouping of the cells in relation to blood vessels. The cells tended to be smaller, with a higher nucleocytoplasmic ratio. The cytoplasm showed a paucity of granules. In some of the cells, it was eosinophilic.

Differences in the brain stem terminations of large- and small-diameter vestibular primary afferents

1995 ◽  
Vol 74 (3) ◽  
pp. 1362-1366 ◽  
Author(s):  
J. A. Huwe ◽  
E. H. Peterson
Keyword(s):  
Brain Stem ◽  
Large Diameter ◽  
Small Diameter ◽  
Movement Control ◽  
Three Dimensions ◽  
Significant Shift ◽  
Axon Diameter ◽  
Vestibular Complex ◽  
The Brain ◽  
Adjacent Brain

1. We visualized the central axons of 32 vestibular afferents from the posterior canal by extracellular application of horseradish peroxidase, reconstructed them in three dimensions, and quantified their morphology. Here we compare the descending limbs of central axons that differ in parent axon diameter. 2. The brain stem distribution of descending limb terminals (collaterals and associated varicosities) varies systematically with parent axon diameter. Large-diameter afferents concentrate their terminals in rostral regions of the medial/descending nuclei. As axon diameter decreases, there is a significant shift of terminal concentration toward the caudal vestibular complex and adjacent brain stem. 3. Rostral and caudal regions of the medial/descending nuclei have different labyrinthine, cerebellar, intrinsic, commissural, and spinal connections; they are believed to play different roles in head movement control. Our data help clarify the functions of large- and small-diameter afferents by showing that they contribute differentially to rostral and caudal vestibular complex.

Speciation in Spirorchis (Trematoda: Spirorchiidae) Infecting the Painted Turtle, Chrysemys picta

1969 ◽  
Vol 55 (6) ◽  
pp. 1169 ◽  
Author(s):  
Chauncey G. Goodchild ◽  
Virginia L. Martin
Keyword(s):  
Chrysemys Picta ◽  
Painted Turtle

Somatotopic studies on red nucleus: spinal projection level and respective receptive fields

1975 ◽  
Vol 38 (4) ◽  
pp. 965-980 ◽  
Author(s):  
J. C. Eccles ◽  
T. Rantucci ◽  
P. Scheid ◽  
H. Taborikova
Keyword(s):  
Spinal Cord ◽  
Red Nucleus ◽  
Receptive Fields ◽  
Anterior Lobe ◽  
Cervical Cord ◽  
Pars Intermedia ◽  
Interpositus Nucleus ◽  
Rubrospinal Tract ◽  
Testing Procedures ◽  
Axonal Projections

The somatotopic inputs into red nucleus (RN) neurons have been studied with special reference to their level of projection in the spinal cord. As inputs we employed either volleys in predominantly cutaneous nerves of forelimb and hindlimb or cutaneous mechanoreceptor discharges evoked by taps to footpads of forelimb and hindlimb. There has been physiological confirmation of the anatomical findings that RD neurons projecting to the lumbar cord are located in the ventrolateral zone of the pars magnocellularis, whereas in the dorsomedial zone are RN neurons with cervical but not lumbar projection. Somatotopically there was found to be a differentiation of input to RN neurons according as they projected to the lumbar or only to the cervical cord. This finding was presented in the form both of tables and of somatotopic maps. As expected, this discrimination was more restrictive for the more selective inputs from pad taps than for nerve inputs. Nevertheless, forelimb inputs often had a considerable excitatory and inhibitory action on lumbar-projecting RN neurons, and vice versa for cervical-projecting neurons. There were two notable somatotopic findings that suggest specificities of connectivities. First, despite the large convergence of IP neurons onto RN neurons (about 50-fold), the degree of somatotopic discrimination was about the same for interpositus and RN neurons with two testing procedures: between inputs from forelimb and hindlimb; and between inputs from pads on one foot. Second, although there was in the interpositus nucleus a considerable topographical admixture of neurons with dominant forelimb or hindlimb inputs, the axonal projections of these neurons were apparently unscrambled on the way to the target RN neurons, so as to deliver the somatotopic specificities observed for two classes of RN neurons; those projecting down the spinal cord beyond L2 level, and those projecting to C2 but not L2. Finally, there is a general discussion of motor control with reference to the pathway; pars intermedia of anterior lobe of cerebellum leads to interpositus nucleus leads to red nucleus leads to rubrospinal tract leads to spinal motoneurons.

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