ISSN:
1432-0878
Schlagwort(e):
Key words: Brain mapping – GABA – Immunohistochemistry – Visual reflexes – Salamanders, Pleurodeles waltli , Triturus alpestris (Urodela)
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
,
Medizin
Notizen:
Abstract. The distribution of GABAergic neurons in brains of the family Salamandridae (Pleurodeles waltli, Triturus alpestris ) has been investigated immunohistochemically with an antibody against gamma-aminobutyric acid (GABA). In adult animals, immunoreactive neurons, fibers, and terminals are abundantly labeled. In the telencephalon, pallial areas contain fewer GABAergic neurons and fibers than basal forebrain areas. The amygdalar complex and the habenulae have a complex pattern of GABA-immunoreactivity that is especially pronounced within the neuropil. The pretectal and basal optic systems are provided with GABAergic neurons, corroborating electrophysiological results. The dorsal thalamus and parts of the torus semicircularis are almost completely devoid of GABA-immunoreactive neurons. In the torus, magnocellular neurons known to project to the contralateral counterpart are distinctly GABA-immunoreactive. During ontogeny, GABAergic neurons arise early when the first reflexive movements occur after mechanical stimulation. At stage 28, cells are labeled initially near the nucleus of the medial longitudinal fasciculus, which is the first supraspinal tract to appear in ontogeny. At stage 30 (still before hatching), GABAergic neurons are found in the pretectum, immunoreactive neurons arising in the dorsal tegmentum slightly later. Both systems are known to mediate basic reflexes in gaze stabilization. The commissura posterior is GABAergic at early stages suggesting an important functional role in homonymous inhibition between both sides. Thus in salamanders, the neurotransmitter GABA displays a complex distribution, similar to that in other vertrebrates. This pattern emerges early in ontogeny.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/s004410050111
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