Control of the pars intermedia of the lizard, Anolis carolinensis

1979 ◽  
Vol 199 (1) ◽  
Author(s):  
Leonard Larsson ◽  
EstebanM. Rodriguez ◽  
Patrick Meurling
Keyword(s):  
Anolis Carolinensis ◽  
Pars Intermedia

Control of the pars intermedia of the lizard, Anolis carolinensis

1979 ◽  
Vol 198 (3) ◽  
Author(s):  
Leonard Larsson ◽  
EstebanM. Rodr�guez ◽  
Patrick Meurling
Keyword(s):  
Anolis Carolinensis ◽  
Pars Intermedia

Control of the pars intermedia of the lizard, Anolis carolinensis

1978 ◽  
Vol 186 (2) ◽  
Author(s):  
E.M. Rodr�guez ◽  
L. Larsson ◽  
P. Meurling
Keyword(s):  
Anolis Carolinensis ◽  
Pars Intermedia

SKIN-COLOUR CHANGES IN THE LIZARD, ANOLIS CAROLINENSIS, IN RESPONSE TO LOCALIZED ELECTRICAL STIMULATION AND LESIONS IN THE DIENCEPHALON

1981 ◽  
Vol 89 (2) ◽  
pp. 241-NP ◽  
Author(s):  
J. H. HEMER ◽  
M. A. SALAS ◽  
J. L. LAPOINTE
Keyword(s):  
Electrical Stimulation ◽  
Functional Relationship ◽  
Colour Change ◽  
Anolis Carolinensis ◽  
Skin Colour ◽  
Pars Intermedia ◽  
Dorsal Region ◽  
Ventral Region ◽  
Colour Changes ◽  
Skin Lightening

A study was made of changes in skin colour in the lizard, Anolis carolinensis, in response to deep electrical stimulation at 0·2 mm intervals throughout the periventricular region of the diencephalon and the anterior brain stem. Double-barrelled glass microelectrodes with tip diameters of 3 μm were used. A 20 μA pulse-train consisting of a 500 Hz signal lasting for 1 s yielded localized responses. Skin darkening occurred only in response to stimulation delivered in the anterior and dorsal region of the diencephalon and skin lightening only in response to stimulation in a small area in the posterior and ventral region of the hypothalamus. Electrical lesions in the latter region resulted in permanent skin darkening. Surgical interruption of the hypothalamo–hypophysial neurosecretory tract did not block skin-colour change in response to dark or light backgrounds. It was concluded that MSH release is under tonic inhibitory control by hypothalamic neurones in Anolis. Both inhibitory and stimulatory neurones can be localized stereotaxically in the diencephalon and neither type corresponds with the neurosecretory neurones of the hypothalamo–hypophysial tract. The functional relationship between the stimulatory neurones and the inhibitory neurones and pars intermedia remains unclear.

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.

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