Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Proceed order?

Export
  • 1
    ISSN: 1573-899X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Conclusions 1. As a result of periodic presentation of combinations of acoustic and electrodermal stimuli 60% of caudate nucleus neurons, 55% of putamen neurons, and 59% of globus pallidus neurons exhibited significant conditioned responses to time of activation (60–69%) and inhibitory (40–31%) type. 2. A definite order of formation of conditioned trace responses was noted: They were formed first in neurons of the putamen, later in the globus pallidus, and latest of all in the caudate nucleus. 3. Unlike in formations studied previously, 42–61% of initially areactive neurons of the caudate nucleus, putamen, and globus pallidus formed conditioned reflexes to time. No significant correlation was found between initial reactivity of the neurons to stimuli of the combined modalities and their ability to form a temporary connection. 4. The universal mechanism of formation and recall of trace activity has individual features in each of the three brain formations studied, and these are determined by the particular nature of its structure and functional organization.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-899X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Conclusion 1. Destruction of the amygdaloid body leads to disturbance of the dependence of the amplitude and probability of appearance of EP on the filling frequency of the tonal volley established in intact animals; maximal values of amplitude and probability of appearance of EP at frequencies of O.8 and 1.6 kHz and between 2.0 and 3.0 kHz are not found in amygdalectomized cats. 2. It is postulated that integrity of the amygdaloid body is an essential condition for the normal functioning of the sensomotor cortex, which is a component of the system distinguishing the biological significance of an acoustic stimulus.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1573-899X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Conclusion 1. Anodal polarization of the parastriate region of the right hemisphere causes dynamic changes in EP, FIA, and interhemispheric interrelations, depending on the strength of photic stimulation, in symmetrical regions of the visual cortex. 2. During polarization the following changes arise in area 18: synergic depression of EP and left-hemispheric dominance during weak stimulation; facilitation of EP in the right hemisphere and its inhibition in the left and weakening of left-sided FIA during stimulation of average intensity; an increase in the response on the left and left-hemispheric dominance during strong stimulation. Synergic depression of EP is observed in area 17 during stimulation of weak and average intensity, and enhancement of EP in all cases of right-hemispheric dominance. 3. During polarization and in the after-period five phases of interhemispheric callosal interrelations are found in area 18: synergic depression and facilitation, reciprocal influences, unilateral depressive and facilitatory influences; the first four phases were observed in area 17. 4. At different periods of existence of a polarization focus of excitation reciprocal interactions were found between commissural influences (a combination of depressive extracallosal and facilitatory callosal influences or of facilitatory and depressive influences respectively), and also synergic interaction between depressive extracallosal and callosal influences. 5. Interhemispheric (callosal and extracallosal) influences, depending on the conditions of photic stimulation and the stage of formation of the polarization focus, either maintain initial levels of EP and FIA or bring about changes in them.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1573-899X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Conclusion 1. Injection of serotonin into the mediobasal hypothalamus inhibits LH secretion in phase P. An analogous effect with serotonin injection into the PO region is seen only in the initial period of this stage. 2. Injection of serotonin into the PO region of OE rats does not alter blood concentration of LH, while injection into the mediobasal region results in a decrease in blood LH. Pretreatment of the OE animals with estradiol leads to a recovery of the inhibitory effects of serotonin injected into the rostral hypothalamus and blocks its effects on the release of LH when it is injected into the mediobasal hypothalamus.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1573-899X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Conclusion 1. Irregular puberty in boys (hypogonadism accompanied by excess sexual pilosis) is due to increased androgenic activity of adrenals. 2. In boys with irregular puberty, blood T levels are depressed and the circadian pattern carries infantile characteristics. 3. In irregular puberty, FSH production is diminished and LH secretion is increased; this is obvious from an evaluation of the basal levels of these hormones and from circadian fluctuations in their concentrations, as well from function tests conducted with HCG, clomifene, and spironolactone.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1573-899X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Conclusion 1. HPL patients characteristically show depressed basal levels of STH. 2. Patients with HPL and radiologically confirmed pituitary adenoma show an altered response of the somatotropic structures to glucose challenge and marked circadian variations in the STH circadian pattern. 3. In patients without a radiological sign of pituitary adenoma STH levels are depressed but the circadian rhythm resembles the normal pattern; the STH fails to show a response to a glucose load and in GTT the STH concentration plot is flattened. 4. The severity of somatotropic functional alteration in HPL is not as important as the nature of the pathologic substrate which underlies the disease. 5. Studies on the circadian STH pattern and its fluctuations in GTT may provide objective criteria in the diagnosis of pituitary microadenoma.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1573-899X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Conclusions 1. Chronic experiments on dogs using a model of instrumental defensive conditioned reflexes connected with maintenance of a particular posture showed that preliminary high-frequency stimulation of the intralaminar thalamic nuclei is accompanied by activation of motor components of the instrumental response and significantly lowers the thresholds of the stimulating current required to obtain caudate arrest. 2. The effect of interaction between stimuli applied to the intralaminar thalamic nuclei and to the head of the caudate nucleus depends on the location of the electrodes in different parts of the striatum. 3. The results suggest that caudate arrest may be caused by potentiation of thalamostriatal activating influences.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1573-899X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Conclusions Before and after bilateral electrolytic destruction of the amygdala and part of the piriform lobe two forms of food-getting reflexes were studied in cats: a previously developed conditioned reflex (running to a feeding dish and removing the food) and an instinctive reflex (to a living mouse or bird). 1. The food-getting conditioned reflex was restored on the 15th–25th day after extensive destruction of the amygdala, although it then took place more slowly and after a longer latent period. Differentiation was not disinhibited. 2. The instinctive food-getting reaction (to a mouse or bird) was lost in seven cats following total loss of the amygdala and was not restored. In three cats this reaction was preserved. In three cats with partial destruction of the amygdala the instinctive reaction was weakened and exhibited irregularly. In the control animals it was unchanged. 3. The results are discussed from the point of view of the physiological role of the amygdala in the regulation of emotional and feeding behavior.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1573-899X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Conclusions 1. Functional connections between structures in the limbic system may change during adaptation of the animal to the external environment, and also after application of small polarizing currents to brain structures. Dominant connections, preserved in different situations, and changes arising in transitional periods can be distinguished. 2. In the process of adaptation, stages of an increase in the number of functional connections, of switching and of blocking can be distinguished. 3. Polarization of cell structures and also of neuron pathways leads to changes in their connections with other structures. The effect of polarization depends on the character of the connections of that particular structure before polarization; if few connections are present initially, polarization increases their number; but if many connections are present in the background, it blocks them. 4. It may be postulated that changes in the steady potential of brain structures play a role in the mechanism of facilitation or weakening of functional connections.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1573-899X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...