Magnetoreception in Rodents: Involvement of the Eyes and the Pineal Organ may be Evidence for a Chronobiological Substrate

Author(s):  
James M. Olcese
Keyword(s):  
1967 ◽  
Vol 45 (1) ◽  
pp. 117-126 ◽  
Author(s):  
M. A. Hafeez ◽  
P. Ford

The morphohistology and some histochemical aspects of the pineal organ in the sockeye salmon were studied. The distal part of the organ lies in a pineal fossa in the cranial roof. Photosensory cells and two kinds of ependymal supporting cells are present throughout its epithelium, which is entirely devoid of either melanin or lipofuchsin. Besides sensory nerve fibers, efferent end-loops are present on the photosensory as well as the supporting cells. The dorsal pineal nerve tract probably contains both sensory and efferent fibers. The apocrine secretion of sensory as well as some supporting cells is probably associated with either the maintenance of a constant chemical composition of the cerebrospinal fluid or with supply of certain chemical substances to the brain tissue. The secretion in the pineal and the subcommissural organ consists of glycogen, mucopolysaccharides, mucoproteins, and aldehyde fuchsin positive granules.It is proposed that the pineal organ is photosensory as well as secretory and that its photosensitivity might be of some significance in the light-dependent behavior of this species in terms of intensity detection.


1990 ◽  
Vol 4 (05) ◽  
pp. 389-397 ◽  
Author(s):  
Peter Ekström ◽  
Hilmar Meissl

AbstractThe pineal complex of anuran &hibians is a directly photosensory organ, encompassing both an extracranial portion, the frontal organ, and an intracranial portion, the pineal organ proper. The projection neurons of the frontal organ respond differentially according to the wavelengths of the light stimuli. The pineal organ, on the other hand, functions mainly as a luminosity meter. Most of its centrally projecting neurons respond to all increases in ambient illumination with decreases in spontaneous firing of action potentials, although some neural units in the pineal organ may respond according to wavelength. This difference in responses to light stimulation may be reflected in the neural organization of the two parts of the pineal complex. In the present study, we have analyzed the morphology of the projection neurons of the frontal and pineal organs of the frog,Rana esculenta, by backfilling of the neurons with horseradish peroxidase through their cut axons. In the pineal organ, several types of centrally projecting neurons were observed: peripherally situated unipolar and multipolar neurons, the dendrites of which extend into a superficial axon plexus that surrounds the pineal epithelium; smaller unipolar, bipolar, or multipolar neurons situated close to the central pineal tract; and radially oriented bipolar neurons, with short dendritic processes oriented towards the lumen of the pineal organ. This latter type was strongly reminiscent of photoreceptor cells. The centrally projecting neurons of the frontal organ were multipolar, and situated in the ventral part of the organ. One photoreceptor-like bipolar neuron was observed in one frontal organ. The neurons of the frontal organ did not form a superficial plexus of neurites. This difference may relate to the different ratio of chromaticity/luminosity units in the frontal and pineal organs.


1991 ◽  
Vol 562 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Hilmar Meissl ◽  
Peter Ekström

Endocrinology ◽  
2001 ◽  
Vol 142 (5) ◽  
pp. 1804-1813 ◽  
Author(s):  
Jack Falcón ◽  
Kristina M. Galarneau ◽  
Joan L. Weller ◽  
Benny Ron ◽  
Galit Chen ◽  
...  
Keyword(s):  

1986 ◽  
Vol 63 (3) ◽  
pp. 285-289 ◽  
Author(s):  
H. Schröder ◽  
L. Vollrath

1986 ◽  
Vol 3 (3) ◽  
pp. 223-234 ◽  
Author(s):  
Piyarat Govitrapong ◽  
Manuchair Ebadi ◽  
L. Charles Murrin
Keyword(s):  

1969 ◽  
Vol 4 (4) ◽  
pp. 489-494 ◽  
Author(s):  
W.B. Quay ◽  
E.L. Bennett ◽  
M.R. Rosenzweig ◽  
D. Krech

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