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21.
Dolbakian EE Merzhanova GKh 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2000,86(5):598-607
The multiple unit activity (MUA) from clusters of adjacent neurones in deep layers of the frontal and motor cortex was recorded in alert cats with different levels of alimentary motivation. Up to 7 spike trains were selected from the MUA. Neurones in the local circuits could be divided into 2 groups: large neurones with prevailing divergent characteristics, and small neurones with prevailing convergent characteristics. A 24-hour food deprivation altered the cross-correlation interneuronal connections with a time delay within the range of 2 to 100 ms. 相似文献
22.
E E Dolbakian G Kh Merzhanova I N Tveritskaia 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》1989,39(5):898-905
By methods of correlation analysis, interrelations were studied of neurones with high, mean and low amplitudes of spikes singled out by amplitude principle from background multineuronal activity of the motor and somatosensory cortical zones, recorded by chronically implanted semi-microelectrodes in dogs. In trained animals, a high positive correlation was observed of singled out neurones discharges, particularly between the neurones with low and mean amplitude of spikes. By the method of cross-interval histogram, dependent relations were revealed of the neurones with different amplitude characteristic mainly of one-sided excitatory character. 相似文献
23.
EG Smirnova GS Muromtsev AV Osipenko EE Khavkin LS Yaguzhinsky 《Biochemistry. Biokhimii?a》1998,63(9):1021-1028
Activation of highly specific biochemical processes by simple chemical agents is demonstrated for morphogenesis (anlage and development of female gametophyte in cereal) and mitosis (in cell cultures and animal and plant tissues). The effects of these agents are tissue-specific. Structure--activity relationship is analyzed in this group of compounds. Thus, the phenomenon reveals the exact pathways of the influence of allelopathic and anthropogenic chemical agents on evolution of plant biocenoses. 相似文献
24.
Hanekamp CE Peels KH Koolen JJ Bonnier HJ 《International journal of cardiovascular interventions》1998,1(2):105-107
In this case report the occurrence of a catheter-induced coronary artery dissection is described. In our patient, angiography showed a mushroom-shaped exudate above the left main coronary artery. Intravascular ultrasound revealed a circular dissection with a huge false lumen connected to the true lumen by a small intimal tear. A brief review of the literature on catheter-induced coronary dissection is included. We believe that this case report provides a good illustration of the need for careful reviewing of indications for angiography. Although procedural risks are low, angiography remains an invasive diagnostic test with the potential to cause severe complications. 相似文献
25.
E E Dolbakian 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》1991,41(2):267-280
In five dogs correlation was studied of heart rate (HR) and motor component of conditioned avoidance reflex (CAR), elaborated by Petropavlovski? method. Stable CAR was expressed in lifting and long (not less than 5-10 sec) holding of the paw on definite height (5-10 cm) for the avoidance of painful electrocutaneous paw stimulation in response to conditioned acoustic stimulus. The level of defensive excitation, evaluated by heart rate change was maximum before the beginning of the conditioned motor reaction. Immediately after lifting and placing the paw in the zone of security a sharp decrease of defensive excitation level ("drive" reduction) took place. Intertrial motor reactions of two types were revealed. The first type imitated the conditioned motor reaction, the second one the usual phasic bending of the paw. Against the background of intertrial movement of the first, operant type a decrease of defensive motivation took similarity as it occurred against the background of CAR during the performance response. 相似文献
26.
E E Dolbakian Ia R Buresh 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》1978,28(2):307-313
Elaboration of an instrumental reaction of getting the food from a narrow tube with a defnite forepaw (handedness) brings about a distinct re-distribution of cellular activity in the motor cortex and in the caudate nucleus, contralateral to the instrumental paw. The changes were observed at a 250 msec. interval before and 512 msec. interval after the beginning of the movement. Two types of cellular discharge changes were recorded: phasic and tonic. The phasic reactions (both inhibitory and activating) were grouped around the beginning of movement, with an average duration of about 100 msec. The tonic reactions lasted a few hundred milliseconds. 相似文献
27.
Khokhlova VN Merzhanova GKh Dolbakian EE 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》2000,50(3):482-491
It was demonstrated in cat experiments that impairment of the retrieval of appetitive instrumental conditioning observed after systemic administration of antagonists of muscarinic central cholinoreceptors scopolamine (a nonselective M1 antagonist) and trihexyphenidyl (relatively selective M1 antagonist) could be connected with central and peripheral side effects of these antagonists. It was established that in case of the absence of side effects (low doses of trihexyphenidyl, 1 mg/kg) the blockade of M1-cholinoreceptors led either to selective fall-off of the motor instrumental reaction with in the presence of contextual behavior and other conditioned reactions or the appearance of errors that seemingly was indicative of the disturbance of triggering and realization of the motor program as the most important component of conditioning performance. The systemic injection of trihexyphenidyl (10 mg/kg), scopolamine (0.03 and 0.06 mg/kg) and nonselective peripheral antagonist methylscopolamine (0.03 mg/kg) led to changes in the general functional state (disorders in the emotional and motivational sphere), the expression of which depended on the individual sensitivity to anticholinergic drugs. The disturbance of CR retrieval observed in parallel with side reactions was characterized by a complete cessation of conditioning and apparently was not associated with memory deterioration. 相似文献
28.
V N Khokhlova G Kh Merzhanova E E Dolbakian 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》2001,51(5):604-616
It was shown previously that peripherally administered antagonists of the central 1 M-cholinoreceptors led to a selective impairment of bar-pressing response in a food-reinforced operant conditioned task but did not alter contextual behavior and functions such as motivation, perception, and locomotion. To obtain information about the central mechanisms of the conditioning impairment, we recorded simultaneously the extracellular multiunit activity from the frontal and motor neocortical areas of five cats trained to acquisition criteria in a food-reinforced operant conditioning task. Multiunit recordings were performed drur 1) normal conditioning; 2) conditioning during subcutaneous administration of muscarinic antagonists scopolamine (0.03 mg/kg), trihexyphenidyl (1 mg/kg), and methylscopolamine (0.03 mg/kg). Autocorrelation analysis showed that scopolamine and trihexyphenidyl but not methylscopolamine led to a significant increase in the tendency of cortical cells to fire in a cyclic way (i.e., the shift of the firing pattern from a single-spike discharge to burst, rhythmic, or rhythmic-burst discharge) both in the motor and frontal areas. Cross-correlation analysis showed that the bursting and rhythmic-bursting cells synchronized their activity within and (in a number of cases) between the cortical areas. These changes in the neuronal activity within the motor cortex and frontal cortex were accompanied by a significant decrease in the functional connectivity both inside and between the cortical areas in parallel with selective impairment of the conditioned response. 相似文献
29.
Hanekamp CE Bonnier HJ Michels RH Peels KH Heijmen EP Hagen Ev Koolen JJ 《International journal of cardiovascular interventions》1998,1(2):81-85
The hemocompatibility and biocompatibility of a stent are determined by the physical and electrochemical properties of the stent surface. The aim of this study was to determine the feasibility, safety and efficacy of implantation of a stent coated with silicon carbide. Baseline characteristics were collected prospectively. The occurrence of cardiac adverse events and the angina score were assessed at clinical follow-up. A total of 193 Tensum stents were implanted in 174 patients. In hospital, one patient experienced stent thrombosis and in 6% of the patients a creatinine kinase elevation to 240 U/l or more occurred. Long-term follow-up was performed in 172 patients, with a mean follow-up of 454 +/- 181 days. Ninety-seven per cent were still alive, 15% had undergone target-vessel revascularization, and 2% had angiographic restenosis and were treated with medication only. Seventy-one per cent of the patients were free of anginal complaints, and 20% had anginal complaints in Canadian Cardiac Society class I or II. The Tensum coronary stent showed to be a safe and efficacious device in this study, with a high primary success rate and favorable long-term clinical followup. 相似文献
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