Histochemical Demonstration of Monoamines in the Hypothalamus of the Lampreys and Ice-goby

Abstract

Since the histochemical procedure for the demonstration of biogenic monoamines was developed by Falck and his coworkers,1)2) many investigators have revealed the catecholamine containing nerve fivers in the median eminence of amphibians,3) birds4)5) and mammals.6-10) These catecholamines have been assumed to be released into the hypophysial portal vessel system and participate in the control of the adenohypophysial function.11)12) In addition, several reports intimated that the releasing factors of ade nohypophysial hormones extracted from the mammalian hypothalamus seem to be the polypeptides.13-15) It was reported that in the teleosts the distribution of the catecholamine containing cells in the hypothalamus seem to be different from that of the higher ver tebrates.16) Among the bony fishes examined, the catecholamine containing neurons of the goldfish were found in the nucleus recessus lateralis hypothalami and nucleus recessus posterioris hypothalami.17)From the phylogenetic and ontogenetic points of view, little information is available in this field of researches. Hence, it was thought to be of value to examine the distribu tion of monoaminergic neurons in the hypothalamus of the lamprey and its ammocoete larva, as one of the most primitive vertebrates supposed to be lacking in the true median eminence and the hypophysial portal vessel system, and so forth.18) The central or neural control of adenohypophysial function of the lamprey, therefore, would be extremely weak.19)To make comparison with the bony fishes, the ice-goby was chosen and localization of monoamines was carried out, because this species has a peculiar pattern of the hypo thalamo-hypophysial complex.20) Materials and MethodsSeveral adult specimens of both river lamprey, Entosphenus japonicus, and brook lamprey, Entosphenus reissneri, were used for the present histochemical and pharmacolo gical experiments (reserpinization). The mature adults of river lamprey were obtained from the estuaries of Shinano and Agano Rivers of Niigata Prefecture at the period of ascending the river in winter season or in May for spawning. The adults and ammocoete

Scanning Electron Microscopy of the Third Ventricular Wall in the Lamprey, <i>Lampetra japonica</i>

“…The general structural pattern of the hypothalamo-hypophysial system of the arctic lamprey has already been described by us (HONMA, 1969;HONMA and HONMA, 1970). As shown in low power scanning electron microscopy, the third ventricle is spacious and cylindrical, though the infundibular floor forms the swollen recessus that is lined with the anterior and posterior neurohypophyses (Fig.…”

Fine Structures of the Cerebrospinal Fluid-Contacting Neurons in the Hypothalamus of the Lamprey, <i>Lampetra japonica</i>

“…Occurrence of monoamine-containing subependymal cells that possess an apical process which is in contact with the cerebrospinal fluid (CSF) has been demonstrated in the hypothalamus of the lamprey by fluorescence microscopy (HONMA, 1969;HONMA and HONMA, 1970;BAUMGARTEN, 1972;KONSTANTINOVA, 1973 KONSTANTINOVA (1973). Using a new filter system for fluorescence microscopy, OCHI and HOSOYA (1974) have also identified two kinds of fluorescent subependymal cells in the hypothalamus and spinal cord of the lamprey, or the blue-green catecholamine-containing cells and the yellow indolalkylamine-containing cells.…”

“…It has been reported that in the hypothalamus of the lamprey examined by 10 11 means of the fluorescence microscope, the fluorescent CSF-contacting nerve cells were distributed around the posterior recess and in the lateral wall of the infundibular recess (HONMA, 1969;HONMA and HONMA, 1970), in the ventral part of the third ventricle, immediately superior to the preoptic recess and in the infundibular and posterior recesses (KONSTANTINOVA, 1973). OCHI and HOSOYA (1974) reported that yellow fluorescent cells containing indolalkylamine (most probably 5-hydroxytryptamine) were less frequently encountered than the blue-green fluorescent cells containing catecholamine in the lateral wall of the third ventricle in the hypothalamus caudal to the optic chiasm.…”

Scanning and transmission electron microscope studies of the supraependymal neurons in the third ventricular wall of the arctic lamprey,Lampetra japonica.

“…In general, these elements are divisible into two categories: the supraependymal neurons and the cerebrospinal fluid (CSF)-contacting subependymal neurons with an intraventricular process. The CSFcontacting neurons in the third ventricular wall of the lamprey brain have been studied in various ways: fluorescence microscopy (HONMA, 1969;HONMA and HONMA, 1970;BAUMGARTEN, 1972;KONSTANTINOVA, 1973;OCHI and HOSOYA, 1974), Golgi impregnation in combination with retrograde axonal transport studies (YUI and HONMA, 1979) and scanning and transmission electron microscopy (SHIODA et al, 1977;NAKAI et al, 1979). However, little is known of the structure and distribution of the supraependymal neurons in the lamprey (NAKAI et al, 1979).…”