Biomedical subjects

A Smollich

Publications and source records attributed to A Smollich.

8 recordsLinked to original sources

PubMed1979

[Morphokinetic effect of PMSG and sex steroids on parts of the cerebral-hypophyseal-gonadal axis of anestrous sheep].

The action of gonadotropins and of sexual steroids on links of the cerebro-hypophyseo-gonadal axis can be morphologically quantified in sheep. In that context, karyovolumetry is a highly dependabel and information-yielding quantitative morphological method. In studies conducted with anoestrous sheep and described in this paper that method has helped to detect an inhibitory effect of PMSG and progesterone upon the activity of neurons of the medial preoptic nucleus of the hypothalamus. The two sexual steroids produced even stronger inhibition of neuronal activity of the arcuate nucleus of the hypothalamus. Such results, when evaluated and re-used under the adequate test conditions might be helpful in identifying structures of central nervous disorders along the cerebro-hypophyseo-gonadal axis and produce reliable information on acting points or general action (activation or inhibition) of active substances as well as on the course of control and regulatory mechanisms.

Anestrus↗

PubMed1978

[Relationship between the limbic system and gonadal function. 3. Quantifiable prepuberal morphokinesis of the basolateral amygdaloid body and the ventral hippocampus formation].

In juvenile female rats the neurons of the limbic system which are attached to the basolateral amygdaloid nucleus and to a circumscribed area of ventral hippocampal formation are characterised by markedly quantifiable morphokinesis between the 21st day of age and onset of the first oestrus. This morphokinesis will take the form of consecutively occurring highly significant volume alterations of the cell nuclei which, in turn, reflect variation in neuronal activity. Some of such variation represents a expression of the general maturation and differentiation of central nervous neurons. The time of occurrence of such variation as well as its peculiar nature also appear to suggest the existence of some special relationship to sexual maturation. This seems to support the conclusion that the basolateral amygdaloid nucleus and the ventral hippocampal formation are attached to the extrahypothalamic central nervous structures of the cerebro-hypophyseal-gonadal axis, in addition to the medial and cortical amygdaloid nuclei. However, the very nature of relationships that may exist between the two investigated components of the limbic system, on the one hand, and sexual maturation as well as gonadal function, on the other, cannot be derived from the results reported in this paper.

Amygdala↗

PubMed1978

Morphological differentation of limbic nuclei during sexual maturation of female rats.

Cell nuclear volumes were measured in the central parts of the medial amygdaloid nucleus (MAN), cortical amygdaloid nucleus (CAN) and basolateral amygdaloid nucleus (BLAN), the anterior part of the ventral hippocampus (VHPC) and, for control, in the parietal cortex of immature female rats at 21, 26, 32, or 36 days of age, or at the onset of puberty. The cortical cell nuclei did not show any variation of their volumes during the period of development under investigation. In all limbic regions studied, a significant increase of cell nuclear size was found from day 21 to day 26 indicating that a general maturation process runs off in the limbic system during the fourth week of life. Cell nuclei were significantly smaller in 32-day-old rats as compared to 26-day-old females in the MAN, CAN and VHPC, but not in the BLAN. From day 32 to day 36, nuclear volumes had distinctively increased in the MAN and BLAN, not changed in the CAN, and further decreased in the VHPC. The first ovulatory oestrus was associated with diminution of nuclear sizes in the MAN and BLAN, and with enlargement of cell nuclei in the CAN and VHPC. The results which suggest a specific development of different limbic nuclei are discussed with regard to recent findings on the gonadotrophin-controlling function of the limbic system in immature and cyclic female rats.

Aging↗

PubMed1978

[Karyovolumetric studies of postnatal differentiation of the amygdaloid complex in ovarectomized rats].

The caryovolumetrically definable prepubertal morphokinesis of the medial, cortical and basolateral amygdaloid nuclei in intact female rats (DOCKE and SMOLLICH 1978), which is probably related to the maturation of the ovulatory meachnisms, could not be demonstrated in females ovariectomized on the first day after birth and autopsied at 21, 26, 32, 36 or 39 days of age. Simultaneously, postnatal castration induced a specific stimulation of the metabolic activity of amygdaloid neurons. A distinct increase of cell nuclear volumes as compared to intact rats was recorded in the medial and basolateral amygdaloid nuclei and, to a lower degree, in the cortical amygdaloid nucleus. Neurons located in the parietal cortex did not respond in this way. The findings support the assumption that the mediocortical and basolateral amygdaloid regions belong to the cerebro-hypophyseo-gonadal axis and are involved in the differentiation and/or maturation of this axis.

Aging↗

PubMed1977

[Relationship between the limbic system and gonadal function. 2. Quantifiable prepuberal differentiation of medial cortical amygdaloid nuclei].

In juvenile female rats beteen the 21st and 26th days of age, the neurons of the medial and cortical amygdaloid nuclei undergo a highly significant karyovolumetrically measurable activation which, however, partially declines almost immediately. Such prepuberal variation of activity was found to be correlated with age-dependent effects of direct interventions with these nuclear regions upon the hypothalamy-pituitary-gonadal axis, e.g. implantation of oestradiol benzoate, stimulation or lesioning. This basically, is a quantitatibe-morphological confirmation of an assumption that had been derived earlier from experimental studies, according to which the mediocortical part of the amygdala undergoes in the prepuberal period a functional muteration or differentiation which is specific and related to puberty and gonadal functions (Döcke, 1976a, b; Döcke et al., 1976).

Aging↗

PubMed1977

[Karyovolumetric studies on possible central-nervous-system action sites of the positive estrogen feedback].

In adult, progesterone-pretreated female rats, the medial preoptic and ventral premamillary nuclei of the hypothalamus, and the medial amygdaloid nucleus of the limbic system exhibit a significant karyovolumetrically measurable activation of their neurons after the subcutaneous administration of an ovulation-inducing dose of oestradiol benzoate. The finding suggests that these nuclear regions are sites of action of the positive oestrogen feedback and are involved in the induction of ovulation. The infundibular and lateral septal nuclei, and the bed nucleus of the stria terminalis were also investigated karyovoumetrically but failed to reveal, at the time of testing, any quantifiable morphokinesis that might have been attributable to the administration of the hormone.

Animals↗

PubMed1976

[Relationship between the limbic system and gonadal function. Quantifiable morphokinesis of the medial amygdaloid nucleus with reference to the estrous cycle].

Karyovolumetric investigation showed that in rat the neurons of the limbic system which are associated with the Pars caudalis of the nucleus amygdaloideus medialis followed a morphokineses which was quantifiable in relation to the oestral cycle. The cell nuclei differed significantly in volume between cycle phases, which was interpreted as morphological correlation between variations in neuronal activity of metabolism. It was thought to be another point in support of the relationship between the amygdala and central-nervous structures of the cerebro-pituitary-gonadal axis.

Amygdala↗

PubMed1975

Studies on extrahypophyseal sites of estrogen action in the induction of ovulation in rats.

To discover possible extrahypophyseal sites of estrogen action in the induction of ovulation, the influence of a s.c. injection of estradiol benzoate (EB) on cell nuclear sizes in the limbic-medial preoptic continuum of progesterone-pretreated cyclic rats was evaluated. The ovulatory dose of 5 mug EB caused a significant increase of nuclear volumes in the medial preoptic nucleus and the anterior and posterior parts of the medial amygdaloid nucleus. Precocious ovulation was induced in prepuberal female rats by unilateral implantation of a molten EB: cholesterol mixture into the posterior part of the mediocortical amygdala (PMCA), but not by implantation into the anterior part of this region (AMCA) or the medial preoptic area (MPA). In adult females injected s.c. with 2.0 mg progesterone on the day post estrus, bilateral implantation of 0.1 or 0.2 mug crystalline EB on the following day did not abolish the delaying effect of progesterone on the preovulatory LH increase and ovulation, when the implants were located in the MPA, lateral septum (LS), bed nucleus of the stria terminalis (BST), AMCA, PMCA or dorsal hippocampus (DHPC), whereas intrapituitary implants were highly effective. However, the bilateral introduction of large tallow pellets containing 0.1 mug EB each, into the LS, BST, AMCA or PMCA advanced ovulation in rats with progesterone-induced 5-day cycles. Equal pellets did neither induced ovulation nor an LH increase after implantation into the MPA or the DHPC. The results suggest that the anterior pituitary, mediocortical amygdala, BST and LS, but not the MPA or DHPC, are sites of the stimulatory feedback of estrogen on gonadotropin secretion in female rats, and that the amygdaloid response to estrogen differs between prepuberal and cyclic females.

Age Factors↗