Wyniki wyszukiwania - Biblioteka Nauki

1

Spontaneous seizure electrocortical activity in rats: relation to arousal level

100%

Gralewicz S. , Luczak C. , Tomas T. , Wiaderna D.

Acta Neurobiologiae Experimentalis

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1994

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tom 54

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nr 1

19-31

2

Sex and strain differences of acoustic startle reaction development in adolescent albino Wistar and hooded rats

63%

Blaszczyk J. , Tajchert K.

Acta Neurobiologiae Experimentalis

|

1996

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tom 56

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nr 4

919-925

EN

Acoustic startle responses (ASR) were studied in 12 young Wistar albino and in 15 hooded rats of both genders. The six week old animals were first exposed to a 6.9 kHz tone pair of 2 ms pulses of 120 db intensity with the inter-stimulus interval (ISI) between 2 and 11 ms. ASR amplitudes and latencies as a function of the ISI, animal strain and gender were recorded and analyzed for ten consecutive weeks. No differences in the ASR amplitude between Wistar and hooded rats were found. ASR amplitude increased during the experimental period and followed body weight increase. Signiflcant differences were also observed between male and female rats in their startle responses to acoustic stimuli. Generally, male subjects responded with a greater ASR amplitude than females, and the changes may be attributed to the difference in neuromuscular development between genders. This experiment sets a background for further developmental studies

3

Apparatus for studying behavior and learning in restrained rats

63%

Soltysik S. , Jackson R. , Jelen P.

Acta Neurobiologiae Experimentalis

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1996

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tom 56

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nr 3

697-701

EN

A new treadmill/stand apparatus for a rat is described.It will be usefull in behavioral experiments when control of the animal's position in the training chamber is required while considerable freedom of movement, including locomotion, is desired.The position and distance relative to sources of stimuli are thus kept constant.The speed and the distance of ambulation are easily monitored.The rats are sufficiently restrained to enable easy recording of various measures such as EKG, EMG or EEG, etc.Classical and instrumental conditioning procedures are easily implemented.An example of the data from acquisition training during Pavlovian conditioning is shown.

4

Spontaneous petit mal-like epileptic seizures in the laboratory rat: an issue that the experimenter should be aware of

63%

Gralewicz S.

Postępy Higieny i Medycyny Doświadczalnej

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2002

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tom 56

|

nr 3

341-351

EN

A certain proportion of laboratory rats of various strains is characterized with a heritable abnormally high propensity for spontaneous, nonconvulsive electrocortical seizures. The seizures have form of bursts of spike-wave discharges (SWD) reminiscent of the human petit-mal epilepsy. The experimenter is usually unaware of this fact. The paper concerns the question of reliability of results obtained on rats samples derived from populations nonhomogenous with respect to the high propensity for SWD seizures.

5

Effect of acoustic stimulus characteristics on the startle response in hooded rats

51%

Blaszczyk J. W. , Tajchert K.

Acta Neurobiologiae Experimentalis

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1997

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tom 57

|

nr 4

315-321

EN

The acoustic startle response (ASR) depends on stimulus parameters such as duration, intensity and particularly on the stimulus rise time. The aim of our study was to determine to what extent the ASR parameters are affected by the spectral characteristics of the stimulus. Therefore, in this experiment the amplitude and the latency of the acoustic startle reflex were assessed for a fixed pulse duration and for a variety of stimulus frequencies ranging between 3 and 23 kHz. The ASRs were studied in 11 adult hooded rats exposed to 2 ms (120 dB SPL) tone pulses of different frequencies presented in random order, with or without 70 dB white noise background. Statistical analysis of the data revealed significant differences between ASR amplitudes for different frequencies. In our experimental situation the rats responded more readily to a low frequency stimulus. The startle amplitude decreased with tonal frequencies and distinguishable difference were seen for 3, 7, and 10 kHz pulses. However, such differences were not readily observed for higher frequencies i.e. 15, 20, 23 kHz. The same pattern of differences was observed when the acoustic stimulus was presented with the white noise background. The observed differences may be attributed, firstly, to a spectral characteristic of the stimulus and thus to an audibility in rats and secondly to a behavioral meaning of a stimulus of a different frequency. cy.

6

Conditioning of fear and conditioning of safety in rats

51%

Walasek G. , Wesierska M. , Zielinski K.

Acta Neurobiologiae Experimentalis

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1995

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tom 55

|

nr 2

121-132

EN

In separate groups of rat forward and backward procedures for classicla defensive conditioning were superimposed on on-going bar pressing for food.The forward conditioned stimulus elicited suppression of bar presses, indicating acquisition of fear.The backward stimulus paired with identical shock elicited behaviour typical for rats in a condition of safety and caused an increase of bar press rate.Enhancement of bar presses acquired in the cource of bacward conditioning was stable, immune to influences from unsignalled shocks presented in the same experimental context, and resistant to extinction when all shocks were discontinued.Properties of the employed variety of the backward conditioning procedure are discussed.QWhen a brief shock overshadowed the onset of a backward stimulus, the remaining portion of the stimulus became a signal of safety.

7

Spectral analysis of cerebellar activity after acute brain injury in anesthetized rats

51%

Culic M. , Blanusa L. M. , GrbicG. , Spasic S. , Jankovic B. , Kalauzi A.

Acta Neurobiologiae Experimentalis

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2005

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tom 65

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nr 1

11-17

EN

We investigated cerebellar electrocortical activity before and after unilateral brain injury in anesthetized rats. Spectral analysis of cerebellar activity was obtained by Fast Fourier Transformation. There was a dominance of delta frequency range, while the wide gamma range presented no more than 5% of the total mean power spectra of cerebellar activity before brain injury. A few minutes after brain injury and within the first 90 minutes, there was a decrease of total mean power spectra and a relative decrease of delta range power to about 30%, some increase of beta range, and an increase of gamma range to 20?25%. Relative increase of gamma range in the cerebellar mean power spectra was still present 120 min after the brain injury, while other changes started to diminish. We suggest that spectral changes within slow and fast (gamma) frequency ranges of cerebellar activity may be indicators of the brain state after acute injury.

8

Maternal behavior in a genetic animal model of absence epilepsy

51%

Dobryakova Y. V. , Dubynin V. A. , van_ L. G.

Acta Neurobiologiae Experimentalis

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2008

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tom 68

|

nr 4

502-508

EN

In this study we quantified maternal behavior in genetic epileptic rats with deficiencies in the DA system known to be involved in maternal behavior in order to assess whether these rats have disturbances in maternal care. Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats, a genetic model for generalized absence epilepsy and Wistar rats were compared. Maternal behavior parameters and activity scores were quantified from post-natal day (PND) 4-6 in an open field in the presence of pups. WAG/Rij rats had less approaches to the pups and higher latencies of approaching them compared to Wistar, while locomotion showed a different pattern over days. This confirms the hypothesis that animals with absence epilepsy show more poor maternal behavior and that these effects cannot be solely attributed to differences in locomotor activity. It is proposed that the reduction in maternal care is attributed to low activity in the mesolimbic DA system.

9

Local classifiers for evoked potentials recorded from behaving rats

51%

Jakuczun W. , Kublik E. , Wojcik D. K. , Wrobel A.

Acta Neurobiologiae Experimentalis

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2005

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tom 65

|

nr 3

425-434

EN

Dynamic states of the brain determine the way information is processed in local neural networks. We have applied classical conditioning paradigm in order to study whether habituated and aroused states can be differentiated in single barrel column of rat's somatosensory cortex by means of analysis of field potentials evoked by stimulation of a single vibrissa. A new method using local classifiers is presented which allows for reliable and meaningful classification of single evoked potentials which might be consequently attributed to different functional states of the cortical column.

10

Correlationof mATPase, cytochrome c oxidase and parvalbumin in rat frozen skeletal muscle fibres

51%

Zawadowska B. , Muntener M.

Folia Biologica

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1997

|

tom 45

97-101

EN

Muscle fibre typing is conventionally performed on unfixed frozen sections. Within the particular classes of fibre types mATPase correlates well with the type of myosin heavy chain (MHC). However, investigation of other properties, e.g., parvalbumin (PV) level, cannot be determined on unfixed frozen sections. Determination of PV, which correlates with the relaxation time, is performed immunohistochemically on fixed tissue. By that method a comparison of mATPase activity and the amount of PV within the same muscle fibre is difficult. The present method, combining histochemistry of mATPase and cytochrome c oxidase with parvalbumin immunohistochemistry on consecutive sections, allows the distinction of six fibre types: I, IB, IIA, IIB, IIAB, IIX, and a C fibre population without division into IC and IIC fibres. The advantages and disadvantages of the present method are discussed.

11

Differentiations of the effect of NMDA on the spatial learning of rats with 4 and 12 week diabetes mellitus

51%

Grzeda E. , Wisniewska R. J.

Acta Neurobiologiae Experimentalis

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2008

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tom 68

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nr 3

398-406

EN

This study examines possible interactions between behavioral effects and influence of N-methyl-D-aspartate acid (NMDA) receptors in 4 and 12-week streptozotocin (STZ) induced diabetic rats. Effects of NMDA receptor agonist on spatial learning were tested in control groups of rats and in rats with 4 and 12 weeks diabetes mellitus (DM). Experimental diabetes was induced by a single intravenous injection of streptozotocin at a dose of 65 mg/kg, dissolved in citrate buffer. We used the water maze task and examined the acquisition and the retrieval of spatial memory in rats. In our present experiments, we observed that DM had no significant influence on acquisition and retrieval in 4 week diabetic rats on Morris water maze, but impaired examined parameters in 12 week diabetic rats in this test. The NMDA receptor agonist did not influence acquisition but increased recall on water maze in 12 week streptozotocin diabetic rats.

12

Neurotoxic effect of sodium tellurite in rat temporal lobe

51%

Gajkowska B. , Smialek M. , Porada D. , Piotrowski P.

Acta Neurobiologiae Experimentalis

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1995

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tom 55

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nr 3

221

13

Exogenous hydrogen sulfide produces hemodynamic effects by triggering central neuroregulatory mechanisms

51%

Ufnal M. , Sikora M. , Dudek M.

Acta Neurobiologiae Experimentalis

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2008

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tom 68

|

nr 3

382-388

EN

Recently, it was found that hydrogen sulfide (H2S) may serve as an important transmitter in peripheral organs as well as in the brain. The aim of the present study was to evaluate the possible function of H2S in the brain regulation of the circulatory system. Experiments were performed on conscious, male, Wistar-Kyoto rats. Mean arterial blood pressure (MABP) and heart rate (HR) were recorded continuously under baseline conditions and during infusions into the lateral cerebral ventricle (LCV) of the experimental animals. In control series LCV infusion of vehicle (Krebs-Henseleit bicarbonate-buffer) did not cause significant changes in MABP or HR. LCV infusion of H2S donor (NaHS) at the rate of 400 nM/h resulted in an increase in MABP, whereas infusions at the rate of 100 nM/h and 200 nM/h failed to change MABP. On the other hand LCV infusion of H2S donor at the rate of 200 nM/h caused a significant increase in HR while infusion at the rate of 400 nM/h produced an increase in HR, which was smaller than this observed during infusion at the rate of 200 nM/h. H2S donor administered at the rate of 100 nM/h failed to affect HR. In conclusion, the present study demonstrates that exogenous hydrogen sulfide changes hemodynamic parameters by centrally mediated mechanisms. The hemodynamic effect seems to be dependent on H2S concentration in cerebrospinal fluid. It appears that the hypertensive response may occur at a concentration, which does not exceed twice the physiological level.

14

The time course of the last contractions during incompletely fused tetani of motor units in rat skeletal muscle

51%

Celichowski J. , Bichler E.

Acta Neurobiologiae Experimentalis

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2002

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tom 62

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nr 1

7-17

EN

The time course of the contraction and the relaxation of individual contractions during incompletely fused tetani of motor units were analyzed. Investigations were performed on fast fatigable (FF), fast resistant (FR) and slow (S) motor units of the rat medial gastrocnemius muscle. Stimulation of a motor unit with a series of nine trains of stimuli at a frequency from 10 to 150 Hz was used and tetani fused to a variable degree were recorded. For fast motor units the procedure was repeated twice and observations were made on potentiated tetani in the second series of stimulation. For each tetanus, the amplitude of the tension increase, the peak amplitude of the contraction, the contraction time and the half-relaxation time were measured in the last contraction of the tension recording. It was observed in all three types of motor units that the last contraction was prolonged in parallel with the increase of fusion of a tetanus. In this contraction, the contraction time slightly decreased whereas the half-relaxation time strongly prolonged. The prolongation of the half-relaxation time was the strongest in tetani of slow units. Moreover, for the last contraction in a tetanus, the rate of changes in tension were studied. The rate of increase in tension during the contraction decreased in parallel with the increase of fusion of a tetanus, whereas the maximal rate of the tension decrease during the relaxation was found in tetani with fusion indices of 0.79, 0.98 and 0.95 for FF, FR and S motor units, respectively. Changes in the time course of contractions in tetani fused to a variable degree can shed light on processes of summation of contractions in unfused tetani at the level of individual motor units.

15

Retention and relearning of spatial delayed alternation in rats after combined or sequential lesions of the prefrontal and parietal cortex

51%

Wortwein G. , Mogensen J. , Divac I.

Acta Neurobiologiae Experimentalis

|

1993

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tom 53

|

nr 1

357-366

EN

Lesions of the medial prefrontal cortex strongly impaired rats delayed alternation behaviour in a T-maze, both when the lesion was inflicted after the initial acquisition of the task and when the lesion was added after criterion performance had been reattained following an of the parietal cortex. Lesions of the parietal cortex did not impair this behaviour, either when the parietal lesion was inflicted after the initial acquisition of the task or when it was added to a prefrontal lesion after criterion performance had beed reattained. Combined, one stage, parietal and prefrontal lesions did not have a stronger effect on delayed alternation than did prefrontal lesions alone. These results indicate that in spite of the strong anatomical connectivity between the prefrontal and parietal "association" cortex the latter is not necessary for the recovery of delayed alternation after prefrontal lesions. In comparison with the parietal cortex, the prefrontal cortex seems to be uniquely involved in mediation of delayed alternation.

16

Early odontoblastic layer response to cavity preparation and acid etching in rats

51%

Nemeth L. , Erman A. , Stiblar-Martincic D.

Folia Biologica

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2006

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tom 54

|

nr 1-2

23-30

EN

The aim of this study was to establish the early odontoblastic layer response and quantitatively to estimate the number of odontoblasts after cavity preparation with and without acid etching. Half of 56 cavities prepared on rats' first upper molars were acid etched. Qualitative and morphometric analyses were made on histological and ultrathin sections 5 min, 6 h, 24 h and 72 h post-operatively. Under the etched cavity, a greater disarrangement of odontoblasts was found, modifications in nuclear shape and condensed chromatin 5 min. post-operatively. An additional reduction of odontoblast number was detected and an increase of aspirated cell number 5 min, 6 h and 24 h post-operatively, pronounced hyperaemia 6, 24 and 72 hours post-operatively and increased odontoblast number 72 hours post-operatively, compared to unetched cavities. In conclusion, injury to the odontoblastic layer was greater, but numerical renewal of the odontoblastic layer began earlier in etched cavities compared to unetched cavities.

17

Overground locomotion in intact rats: contact electrode recording

51%

Gorska T. , Majczynski H. , Zmyslowski W.

Acta Neurobiologiae Experimentalis

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1998

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tom 58

|

nr 3

227-237

EN

The aim of the experiments was to check the validity of the method of contact electrodes for studying overground locomotion in the rat. The basic indices of locomotion, obtained in 7 intact rats with at least 100 steps recorded in each, were analysed and compared with those described by other authors using different methods of movement recording. It was found that the method of contact electrodes gives reproducible and reliable results and may thus be used in further experiments of rat locomotion after CNS lesions.

18

Third genetic polymorphism of tear proteins Rtp-3 in rat

51%

Woszczynski M.

Folia Biologica

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1995

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tom 43

|

nr 1-2

69-73

EN

Two genetic markers, tear proteins RTP-1 and RTP-2, were studied in six inbred rat strains by the agarose gel electrophoretic method.An RTP-2A fast migration band was found in M520/W, AUG/W, and BN/HanW strain whereas in WAG/W, L-E/W and SPRD/W rats no RTP-2 band was detectable.In the case of RTP-1 there always occured only one band with a different migration speed in gel according to the representing allele.The slow band RTP-1B was observed in rat strains WAG/W, AUG/W, SPRD/W, L-E/W, and M520/W, the fast band RTP-1A being observed only in BN/HanW rats.Moreover, a considerable sex difference in the expression of tear protein in all the tested strains was observed.The expression of a third independent rat tear protein locus whose product, controlled by androgens, was found to be present only in females and castrated males.It is proposed to designate it Rtp-3 with three alleles.The discrepancy of these results with the observation by Kondo et al. concerning Rtp-1 alleles has been discussed.

19

Contralateral somatosensory neglect in unrestrained rats after lesion of the paretial cortex of the left hemisphere

51%

Holm S. , Mogensen J.

Acta Neurobiologiae Experimentalis

|

1993

|

tom 53

|

nr 4

569-576

20

Enhanced pressor response to centrally administered vasopressin in WKY rats on high sodium diet

51%

Zera T. , Ufnal M.

Acta Neurobiologiae Experimentalis

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2005

|

tom 65

|

nr 2

145-150

EN

Four week old Wistar-Kyoto (WKY) rats were divided into two groups. The experimental group (n=7) was receiving a high sodium diet (3.28% Na+) and the control group (n=7) a normal sodium diet (0.22% Na+). After 8 weeks, subjects were chronically implanted with the lateral cerebral ventricle (LCV) cannulas and with the femoral artery catheters. Three series of experiments were carried out on the experimental and control groups. In each series mean arterial pressure (MAP) and heart rate (HR) were recorded for 10 min before and 30 min after the LCV infusion. In series 1 artificial cerebrospinal fluid (aCSF) was administered (2 mul/15 s). In series 2 AVP was infused (20 ng/2 mul aCSF/15 s). In series 3 V1a receptor antagonist (V1 ANT), d(CH2)5[Tyr(Me)2,Ala-NH29]AVP, was applied (80 ng/mul aCSF/15 s). There was no difference in baseline MAP and HR between the experimental and control groups. LCV infusion of aCSF had no effect on MAP and HR. LCV infusion of AVP produced a significant increase of MAP, which was greater in the group on the high sodium diet than in the group on normal sodium diet. The experimental group showed a longer hypertensive effect of centrally applied AVP in comparison to the control. LCV administration of V1 ANT did not exert a significant effect on circulatory parameters. These results suggest that the prolonged high sodium diet does not induce hypertension in WKY rats, but it enhances the pressor function of the central vasopressinergic system.