| 1. |
- Ekström, Peter
(författare)
-
Central neural connections of the pineal organ and retina in the teleost Gasterosteus aculeatus L.
- 1984
-
Ingår i: Journal of Comparative Neurology. - : Wiley. - 0021-9967. ; 226:3, s. 321-335
-
Tidskriftsartikel (refereegranskat)abstract
- The relations of the central neural connections of the pineal organ to those of the retinae of the lateral eyes were investigated in the three‐spined stickleback, Gasterosteus aculeatus L. (Teleostei), by anterograde and retrograde transport of horseradish peroxidase (HRP). HRP was applied to the crushed pineal stalk and/or injected into the left or the right eye. Both pineal and retinal efferents project to area praetectalis, dorsal and ventral thalamic areas, and dorsal tegmentum. The most notable overlapping occurs in nucleus commissurae posterioris of area praetectalis. Pineal efferents also innervate the habenular nuclei and dorsal hypothalamus, while retinal efferents innervate rostral hypothalamus, ventrolateral thalamus, and tectum opticum. A small number of retinofugal axons recross and innervate the ipsilateral nucleus anterioris periventricularis and area praetectalis. After intraocular HRP injections, labeled perikarya were located both in retinofugal terminal areas and in areas not receiving direct retinal input, such as the telencephalic nucleus olfactoretinalis, deep tectal layers, and an area rostroventral to nucleus dorsolateralis thalami. No neurons afferent to the pineal organ were demonstrated. The close association of pineal efferents with retinofugal and possible retinopetal elements is in accordance with the view that both systems are potential neural mediators of photoperiodic events in the teleostean circadian system.
|
|
| 2. |
- Ekström, Peter, et al.
(författare)
-
Distribution of 5‐hydroxytryptamine (serotonin) in the brain of the teleost Gasterosteus aculeatus L.
- 1984
-
Ingår i: Journal of Comparative Neurology. - : Wiley. - 0021-9967. ; 226:3, s. 307-320
-
Tidskriftsartikel (refereegranskat)abstract
- The distribution of serotoninergic neurons in the brain of the three‐spined stickleback was demonstrated with the indirect peroxidase‐antiperoxidase (PAP) immunohistochemical method with antibodies against serotonin. Serotoninergic perikarya were demonstrated in the brainstem reticular formation (nucleus raphe dorsalis, nucleus raphe medialis, and nucleus tegmenti dorsalis lateralis) and in the periventricular ventral thalamus and hypothalamus (nucleus ventromedialis thalami, nucleus posterioris periventricularis, nucleus recessus lateralis, and nucleus recessus posterioris). After pharmacological pretreatment of the animals with a monoamine oxidase inhibitor, serotoninergic perikarya were also visualized in area praetectalis and in the medial brainstem, caudal to nucleus raphe medialis. Whereas the cell groups of the brainstem give rise to both ascending and descending pathways, it was not possible to analyze the distribution of efferent projections from the diencephalic cell groups. Distribution of serotoninergic axons showed marked regional differences. Only scattered varicose fibers were demonstrated in the cerebellum, the facial lobes, and the lateral line lobes. In the mesencephalon, the dorsal periventricular tegmentum and the central gray receive only small numbers of serotoninergic axons, while torus semicircularis and the visual layers of tectum opticum are profusely innervated. In the diencephalon, the hypothalamus and ventral thalamus generally display the highest density of serotoninergic axons. Exceptions are found in nucleus glomerulosus and the ventromedial portion of lobus inferioris, where densities are low. In the telencephalon, the density of serotoninergic axons is very high in area dorsalis pars medialis and pars lateralis dorsalis, but low in area dorsalis pars dorsalis and pars lateralis ventralis, and intermediate in area ventralis.
|
|
