ISSN:
1432-1106
Keywords:
Transmitter substances
;
Acetylcholine
;
5-Hydroxytryptamine
;
Neurohumoral release
;
Hypothalamus
;
Thalamus
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The diencephalon of the unanaesthetized rhesus monkey was explored for sites which release either 5-hydroxytryptamine (5-HT) or acetylcholine (ACh), or both, spontaneously. In 34 monkeys “push-pull” perfusion cannulae were implanted so that the tips rested in 66 different loci of the hypothalamus and thalamus. Each site was perfused for 30 min at 24–48 h intervals, and usually three perfusions were carried out for the 5-HT assays and three for ACh assays. Within 45 distinct loci of the hypothalamus, four types of sites were identified at which only 5-HT was released, only ACh was released, both 5-HT and ACh were released, or neither substance was detected. Within 21 sites representing three of the major masses of thalamic nuclei (lateral, medial and posterior), the same kinds of sites were found. In the hypothalamic sites, 5-HT output varied between 0.1–2.0 ng per 30 min perfusion interval, whereas ACh varied between 0.2–3.0 ng per 30 min. In thalamic loci, 5-HT release ranged between 0.5–3.0 ng per 30 min and ACh between 0.1–10.0 ng per 30 min. The sites which released 5-HT and ACh were scattered widely and unevenly throughout these diencephalic structures. However, there was a greater release of 5-HT in the anterior and in the posterior hypothalamus, and more ACh in the thalamus than in the hypothalamus.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00233974
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