ON THE HORMONAL CONTROL OF CELL DIFFERENTIATION IN THE OVOTESTIS OF SLUGS (GASTEROPODA: PULMONATA)

1964 ◽  
Vol 42 (2) ◽  
pp. 195-199 ◽  
Author(s):  
D. Pelluet

If the tentacles of Arion ater and Milax sp. are cut off, the animals show an increased number of eggs after a period of 3 or more weeks. When extracts of the brain and tentacles are injected into the animals without tentacles, the number of eggs produced may approach that of the normal animal or it may be somewhat higher, depending on the relative amounts of the brain and tentacle hormones in the injected solution. This work supports the idea that there are two distinct hormones controlling the differentiation of the germ cells: one, in the brain, concerned with egg production; the other, in the tentacles, stimulating sperm. The two hormones form a balanced system in the normal animal with the tentacular hormone appearing first.

2021 ◽  
Vol 15 (2) ◽  
pp. 130-139
Author(s):  
Daniele Rosa Xavier ◽  
Auricelio Alves de Macedo ◽  
Larissa Sarmento dos Santos ◽  
Taynan Dulce da Silva Rosa ◽  
Ellainy Maria Conceição Silva ◽  
...  

Histopathological and spermatogenesis classification by Johnsen is widely used in the germinal epithelium maturation analysis, besides identifying pathological alterations able to cause subfertility and even infertility. The aim of this study was to analyze cell-differentiation histopathological data and to correlate them with expression of PRM-1, TNP-2, 17β-HSD3, LHR, generic MHC-I, MIC-B, NC1 and NC3 genes, involved in bovine spermatogenesis using qRT-PCR from testicular parenchyma. Based on Johnsen’s criteria, the results showed normal spermatogenic activity in these animals, classified at 6, 7 and 8 scores. The qRT-PCR analysis expression showed that MHC-I (generic) gene was less expressed than all the other genes in evaluated scores (p < 0.05) and, PRM-1 and TNP-2 were the most expressed genes (p < 0.05). The PRM-1 gene expression was significantly higher than TNP-2 (p < 0.05). Comparing scores, 17β-HSD3 gene expression was lower (p < 0.05) in score 6 when compared to scores 7 and 8 animals. It was also observed that PRM-1 expression was lower in score 6 when compared to 7, as well as TNP-2 gene was less expressed in the score 6 (p < 0.05) when compared to 7 and 8 scores. Our results demonstrated that MHC I (generic), MIC-B, NC1, NC3, and LHR genes are poorly expressed in bovine testis, suggesting their marginal action on spermatogenesis. Instead, PRM-1, TNP-2, and 17β-HSD3 expression were higher, supporting the notion that these genes can act directly on the germ cells differential development during bovine spermatogenesis.


1961 ◽  
Vol 39 (6) ◽  
pp. 789-805 ◽  
Author(s):  
D. Pelluet ◽  
Nancy Jane Lane

Cytodifferentiation in the germinal epithelium of the ovotestis of slugs is approached experimentally. The tentacles of the slugs were cut off and the animals maintained for different lengths of time before the ovotestis was examined. In both species of slug used, Arion subfuscus and Arion ater, the experimental animals showed a noticeable increase in the number of eggs, when compared with the control. Solutions of brain homogenate and tentacle homogenate were then injected separately into intact animals. The brain solution apparently stimulated the production of eggs, the numbers being nearly equal to that produced by cutting the tentacles. The tentacle solution injected into the animals produced no increase in the number of eggs, and in young animals the normal growth of the ovotestis was inhibited. Cytological study of the brain and tentacles reveals neurosecretory cells and a close association with the blood system of the animal, suggesting a basis for a hormonal system. In this case, a theoretical concept of a dual hormonal control is put forward, to explain the production of male cells first by the tentacle hormone, followed by egg production under the control of a brain hormone.


1970 ◽  
Vol 24 (01/02) ◽  
pp. 026-032 ◽  
Author(s):  
N. A Marsh

SummaryMolecular exclusion chromatography was performed on samples of urine from normal and aminonucleoside nephrotic rats. Normal urine contained 2 peaks of urokinase activity, one having a molecular weight of 22,000 and the other around 200,000. Nephrotic urine contained three peaks of activity with MW’s 126,000, 60,000 and 30,000. Plasma activator determined from euglobulin precipitate had a MW. in excess of 200,000. The results indicate that in the normal animal, plasma plasminogen activator does not escape into the urine in substantial quantities but under the conditions of extreme proteinuria there may be some loss through the kidney. The alteration in urokinase output in nephrotic animals indicates a greatly disordered renal fibrinolytic enzyme system.The findings of this study largely support the hypothesis that plasma plasminogen activator of renal origin and urinary plasminogen activator (urokinase) are different molecular species.


1968 ◽  
Vol 59 (3) ◽  
pp. 479-486 ◽  
Author(s):  
Lars-Ake Idahl ◽  
Bo Hellman

ABSTRACT The combination of enzymatic cycling and fluorometry was used for measuring glucose and glucose-6-phosphate in pancreatic β-cells from obese-hyperglycaemic mice. The glucose level of the β-cells corresponded to that of serum over a wide concentration range. In the exocrine pancreas, on the other hand, a significant barrier to glucose diffusion across the cell membranes was demonstrated. During 5 min of ischaemia, the glucose level remained practically unchanged in the β-cells while it increased in the liver and decreased in the brain. The observation that the pancreatic β-cells are characterized by a relatively low ratio of glucose-6-phosphate to glucose may be attributed to the presence of a specific glucose-6-phosphatase.


Author(s):  
Walter Ott

Descartes’s treatment of perception in the Optics, though published before the Meditations, contains a distinct account of sensory experience. The end of the chapter suggests some reasons for this oddity, but that the two accounts are distinct is difficult to deny. Descartes in the present work topples the brain image from its throne. In its place, we have two mechanisms, one purely causal, the other inferential. Where the proper sensibles are concerned, the ordination of nature suffices to explain why a given sensation is triggered on the occasion of a given brain motion. The same is true with regard to the common sensibles. But on top of this purely causal story, Descartes re-introduces his doctrine of natural geometry.


1971 ◽  
Vol 34 (4) ◽  
pp. 537-543 ◽  
Author(s):  
Richard A. Lende ◽  
Wolff M. Kirsch ◽  
Ralph Druckman

✓ Cortical removals which included precentral and postcentral facial representations resulted in relief of facial pain in two patients. Because of known failures following only postcentral (SmI) ablations, these operations were designed to eliminate also the cutaneous afferent projection to the precentral gyrus (MsI) and the second somatic sensory area (SmII). In one case burning pain developed after a stroke involving the brain stem and was not improved by total fifth nerve section; prompt relief followed corticectomy and lasted until death from heart disease 20 months later. In the other case persistent steady pain that developed after fifth rhizotomy for trigeminal neuralgia proved refractory to frontal lobotomy; relief after corticectomy was immediate and has lasted 14 months. Cortical localization was established by stimulation under local anesthesia. Each removal extended up to the border of the arm representation and down to the upper border of the insula. Such a resection necessarily included SmII, and in one case responses presumably from SmII were obtained before removal. The suggestions of Biemond (1956) and Poggio and Mountcastle (1960) that SmII might be concerned with pain sensibility may be pertinent in these cases.


2016 ◽  
Vol 26 (04) ◽  
pp. 1650016 ◽  
Author(s):  
Loukianos Spyrou ◽  
David Martín-Lopez ◽  
Antonio Valentín ◽  
Gonzalo Alarcón ◽  
Saeid Sanei

Interictal epileptiform discharges (IEDs) are transient neural electrical activities that occur in the brain of patients with epilepsy. A problem with the inspection of IEDs from the scalp electroencephalogram (sEEG) is that for a subset of epileptic patients, there are no visually discernible IEDs on the scalp, rendering the above procedures ineffective, both for detection purposes and algorithm evaluation. On the other hand, intracranially placed electrodes yield a much higher incidence of visible IEDs as compared to concurrent scalp electrodes. In this work, we utilize concurrent scalp and intracranial EEG (iEEG) from a group of temporal lobe epilepsy (TLE) patients with low number of scalp-visible IEDs. The aim is to determine whether by considering the timing information of the IEDs from iEEG, the resulting concurrent sEEG contains enough information for the IEDs to be reliably distinguished from non-IED segments. We develop an automatic detection algorithm which is tested in a leave-subject-out fashion, where each test subject’s detection algorithm is based on the other patients’ data. The algorithm obtained a [Formula: see text] accuracy in recognizing scalp IED from non-IED segments with [Formula: see text] accuracy when trained and tested on the same subject. Also, it was able to identify nonscalp-visible IED events for most patients with a low number of false positive detections. Our results represent a proof of concept that IED information for TLE patients is contained in scalp EEG even if they are not visually identifiable and also that between subject differences in the IED topology and shape are small enough such that a generic algorithm can be used.


1917 ◽  
Vol 25 (4) ◽  
pp. 557-580 ◽  
Author(s):  
Carroll G. Bull

Streptococci cultivated from the tonsils of thirty-two cases of poliomyelitis were used to inoculate various laboratory animals. In no case was a condition induced resembling poliomyelitis clinically or pathologically in guinea pigs, dogs, cats, rabbits, or monkeys. On the other hand, a considerable percentage of the rabbits and a smaller percentage of some of the other animals developed lesions due to streptococci. These lesions consisted of meningitis, meningo-encephalitis, abscess of the brain, arthritis, tenosynovitis, myositis, abscess of the kidney, endocarditis, pericarditis, and neuritis. No distinction in the character or frequency of the lesions could be determined between the streptococci derived from poliomyelitic patients and from other sources. Streptococci isolated from the poliomyelitic brain and spinal cord of monkeys which succumbed to inoculation with the filtered virus failed to induce in monkeys any paralysis or the characteristic histological changes of poliomyelitis. These streptococci are regarded as secondary bacterial invaders of the nervous organs. Monkeys which have recovered from infection with streptococci derived from cases of poliomyelitis are not protected from infection with the filtered virus, and their blood does not neutralize the filtered virus in vitro. We have failed to detect any etiologic or pathologic relationship between streptococci and epidemic poliomyelitis in man or true experimental poliomyelitis in the monkey.


2018 ◽  
Vol 48 (1) ◽  
pp. 150-159
Author(s):  
Jonathan M. P. Wilbiks ◽  
Sean Hutchins

In previous research, there exists some debate about the effects of musical training on memory for verbal material. The current research examines this relationship, while also considering musical training effects on memory for musical excerpts. Twenty individuals with musical training were tested and their results were compared to 20 age-matched individuals with no musical experience. Musically trained individuals demonstrated a higher level of memory for classical musical excerpts, with no significant differences for popular musical excerpts or for words. These findings are in support of previous research showing that while music and words overlap in terms of their processing in the brain, there is not necessarily a facilitative effect between training in one domain and performance in the other.


2009 ◽  
Vol 102 (4) ◽  
pp. 2526-2537 ◽  
Author(s):  
Sylvie Lardeux ◽  
Remy Pernaud ◽  
Dany Paleressompoulle ◽  
Christelle Baunez

It was recently shown that subthalamic nucleus (STN) lesions affect motivation for food, cocaine, and alcohol, differentially, according to either the nature of the reward or the preference for it. The STN may thus code a reward according to its value. Here, we investigated how the firing of subthalamic neurons is modulated during expectation of a predicted reward between two possibilities (4 or 32% sucrose solution). The firing pattern of neurons responding to predictive cues and to reward delivery indicates that STN neurons can be divided into subpopulations responding specifically to one reward and less or giving no response to the other. In addition, some neurons (“oops” neurons) specifically encode errors as they respond only during error trials. These results reveal that the STN plays a critical role in ascertaining the value of the reward and seems to encode that value differently depending on the magnitude of the reward. These data highlight the importance of the STN in the reward circuitry of the brain.


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