Olfactory rhythm in the electrical activity of the human amygdaloid nucleus

Summated electrical activity of the human amygdaloid nucleus was investigated in the neurosurgical clinic by chronically implanted electrodes. It was found that odoriferous stimulation of this structure produced bursts of rapid rhythm (20–30 cps, 30–50 µV). The quasisinusoidal waves of olfactory rhythm consist of sinusoidal components which are more pronounced within the 20–30-Hz frequency range. Spindling of 1–3 sec duration occurs at the end of inhalation and the beginning of exhalation in time with breathing. During monorhinal breathing this activity, whose amplitude depends on degree of olfactory stimulation, can only be recorded ipsilaterally. Room air also activates the amygdaloid nucleus, but less strongly than odoriferous substances: No characteristic odor-dependent differences were discovered in the frequency range of the olfactory rhythm within a 20–30-Hz band.Institute of Physiology, Kiev State University, Kiev. Translated from Neirofiziologiya, Vol. 18, No. 1, pp. 61–69, January–February, 1986.     

Effect of Urea and Thiourea on Migration Activity of Climbing Perch Anabas testudineus

Journal of Ichthyology - The influence of urea and thiourea on the dynamics of the migration activity of climbing perch Anabas testudineus was studied. The exposure of climbing perch to 0.05%...     

Change of Rheoreaction and Concentration of Thyroid Hormones in Blood of Juvenile Rainbow Trout Oncorhynchus mykiss during Starvation

Journal of Ichthyology - Rheoreaction and concentration of thyroid hormones in blood of juvenile rainbow trout Oncorhynchus mykiss is studied during starvation (12 days). It is found that...     

Thyroid and Sex Steroid Hormone Level in the Pink Salmon Oncorhynchus gorbuscha during Marine and Freshwater Periods of Spawning Migration

Journal of Ichthyology - Thyroid and sex steroid hormones have been studied in spawners of the pink salmon Oncorhynchus gorbuscha at the stage of changing the marine section of the spawning...     

Modification of the structure of penial glands in males of the intertidal molluscs Littorina saxatilis and L. obtusata under the influence of the infestation by trematode parthenites

Sporocycts of the "pygmaeus" microphallides (Microphallus piriformes) are localized in hepatopancreas and gonads of Littorina molluscs causing total parasitic castration. A histological study of penial glands in Littorina saxatilis and L. obtusata males infested with trematodes M. piriformes has been made. Copulatory organs of noninfested molluscs, molluscs after recent contamination (with not completely formed daughter sporocysts), and molluscs containing mature metacercariae inside daughter sporocysts were examined. Based on the data obtained, probable dynamics of the histological structure of infested glandular apparatus was established. It was shown, that the trematode infestation have an influence on the muscular and secretory parts of penial glands. The wall of the penial gland muscular capsule becomes more fine in infested L. saxatilis. On the contrary, this wall is vastly thicker in infested L. obtusata, as compared with noninfested individuals. Glandular cells of the molluscs' penial glands decreases the amount of granular secret in both species. In L. obtusata the number of secretory cells is shown to be reduced up to their total disappearance. The above pathological changes probably prevent normal function of penial glands.     

Effect of methyltestosterone on physiological state and rheoreaction of rainbow trout <Emphasis Type="Italic">Parasalmo mykiss</Emphasis> (=<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>) under unfavorable keeping conditions

The effect of methyltestosterone given with feed during one and two months on the state of gonads, the level of thyroid, and sex steroid hormones in blood and on rheoreaction is studied in juvenile rainbow trout Parasalmo mykiss (=Oncorhynchus mykiss) raised under unfavorable conditions (tropics, Vietnam). In comparison with the control, in the experimental group, the part of sterile specimens was higher (83 vs. 35%), the part of males was lower (17 vs. 40%), while females and hermaphrodites were absent. At prolonged starvation (12 days), the experimental specimens demonstrated lower increase of the level of thyroid and sex steroid hormones in blood than that in the control specimens. Methyltestosterone modified the behavior of rainbow trout in water flow: delivery of the hormone in food during 1 month increased the part of fish moving against the flow and suppressed movement both upstream and downstream during 2 months. Thus, methyltestosterone negatively influences the physiological condition and adaptation capacity of rainbow trout.     

The influence of the degree of infestation with trematode parthenites on the structure of penial glands in the mollusks Littorina saxatilis of different age

Histological and confocal microscopy studies of the structure of penial glands in the Littorina saxatilis males were carried out. The examined mollusks belong to two age groups and were at different stages of spontaneous infection with a trematode from the pygmaeus species group (Microphallus piriformes). Based on comparative analysis of microscopic sections of copulative organs in infested and non-infested mollusks, data on the modifications in histological structure ofpenial glands were obtained. From these data we can suggest that the infestation have an influence on all parts of the gland. Decrease of secret production and reduction of muscular capsule (down to its disappearance) were observed. We suppose that changes in the penial glands structure prevent their normal functioning. In the mollusks infested on reaching the sexual maturity, gradual reduction of distal part of reproductive system was observed, while in the mollusks infested before the sexual maturity, development of ancillary part of reproductive system was blocked.     

Cytological status of the gonads and the level of thyroid and sex hormones in juvenile Black Sea trout,Salmo trutta labrax,of two phenotypic forms

Cytological state of gonads and hormonal status was studied in juvenile (15-month-old) Black Sea trout Salmo trutta labrax of the two phenotypic forms (resident and migratory). The differences in the rates of hametogenesis in the compared forms were revealed. It is shown that the spermatogenesis in the resident form is more intensive; on the other hand, the ovogenesis is slower. The levels of thyroxin and testosterone in blood are significantly higher in the groups of fish with intensively running gametogenesis. It is found that the concentration of triiodothyronine is slightly slower in the resident form than in the migratory. The correlation between levels of thyroid and sex steroid hormones is revealed.     

Condition of Sex Glands in the Young of the Current Year of Rainbow Trout Subjected to Surfagon Injections

Condition of sex glands and thyroid and steroid hormone levels in the blood are assessed in the young of the current year of rainbow trout cultivated in the high-mountain area of South Vietnam and subjected to injections of surfagon (synthetic analogue of gonadotropin-releasing hormone). In the conditions of the trout hatchery (Vietnam), gonads of the young of the current year are characterized by substantial anomalies, including an appearance (in addition to females and males) of hermaphrodite and sterile individuals. A single injection of surfagon 1 month after hatching leads to stabilization of the development of sex glands and decrease of the proportion of sterile individuals (from 41 to 22%). This study is the first attempt of the assessment of the effect of the injection of gonadotropin-releasing hormone analogue on the development of sex glands in the early ontogeny of fishes.     

Effects of Modeling of Hypercalcemia and β-Amyloid on Cultured Hippocampal Neurons of Rats

Neurophysiology - Alzheimer’s disease (AD) is the most common type of dementia; it is characterized by accumulations of amyloid (Aβ) plaques and neurofibrillary tangles in the brain....