Heterogeneous associative plasticity in the auditory cortex induced by fear learning - novel insight into the classical conditioning paradigm.

We used two-photon calcium imaging with single-cell and cell-type resolution. Fear conditioning induced heterogeneous tuning shifts at single-cell level in the auditory cortex, with shifts both to CS+ frequency and to the control CS- stimulus frequency. We thus extend the view of simple expansion of CS+ tuned regions. Instead of conventional freezing reactions only, we observe selective orienting responses towards the conditioned stimuli. The orienting responses were often followed by escape behavior.

Acute and chronic role of nitric oxide, renin-angiotensin system and sympathetic nervous system in the modulation of calcium sensitization in Wistar rats.

Principal vasoactive systems - renin-angiotensin system (RAS), sympathetic nervous system (SNS), nitric oxide (NO) and prostanoids - exert their vascular effects through the changes in calcium levels and/or calcium sensitization. To estimate a possible modulation of calcium sensitization by the above vasoactive systems, we studied the influence of acute and chronic blockade of particular vasoactive systems on blood pressure (BP) changes elicited in conscious normotensive rats by acute dose-dependent administration of Rho-kinase inhibitor fasudil. Adult male chronically cannulated Wistar rats were used throughout this study. The acute inhibition of NO synthase (NOS) by L-NAME enhanced BP response to fasudil, the effect being considerably augmented in rats deprived of endogenous SNS. The acute inhibition of prostanoid synthesis by indomethacin modified BP response to fasudil less than the acute NOS inhibition. The chronic NOS inhibition caused moderate BP elevation and a more pronounced augmentation of fasudil-induced BP changes compared to the effect of acute NOS inhibition. This indicates both short-term and long-term NO-dependent attenuation of calcium sensitization. Long-term inhibition of RAS by captopril caused a significant attenuation of BP changes elicited by fasudil. In contrast, a long-term attenuation of SNS by chronic guanethidine treatment (in youth or adulthood) had no effect on BP response to fasudil, suggesting the absence of SNS does not affect calcium sensitization in vascular smooth muscle of normotensive rats. In conclusion, renin-angiotensin system contributes to the long-term increase of calcium sensitization and its effect is counterbalanced by nitric oxide which decreases calcium sensitization in Wistar rats.

[Role of echocardiography in surgery of pulmonary tuberculosis]. / Rol' ekhocardiografii vo ftiziokhirurgii.

Doppler echocardiography was used to examine 26 patients aged 18 to 65 years who had undergone different surgical interventions for disseminated and acutely progressive pulmonary tuberculosis. Nineteen patients were diagnosed as having fibrocavernous pulmonary tuberculosis; 6 and 1 patients had caseous pneumonia and disseminated pulmonary tuberculosis. Echocardiography was performed with a LSC-700 echotomograph (Piker International, USA) by the routine procedure. Analyzing central hemodynamic parameters in the patients identified 3 types of hemodynamics: hypokinetic, eukinetic, and hyperkinetic, which made it possible to perform a course of cardial therapy adequately in the preoperative period. Preoperatively, 21 (80.8%) patients were found to have elevated mean pulmonary pressures and 5 patients had pulmonary pressures in the normal ranges. In the uncomplicated postoperative period, pulmonary pressures gradually decreased and reached normal values in some patients.