[NADPH-DIAPHORASE REACTIVITY IN THE VENTRAL HORN OF THE FELINE SPINAL CORD DURING ACUTE MUSCLE INFLAMMATION].

The aim of this research was to reveal the changes in the NADPH-d reactivity in the lumbal spinal cord (L6/L7) of cats with unilateral acute myositis of the mm. gastrocnemius-soleus after intramuscular injections of carrageenan. The effect of unilateral muscle inflammation was expressed in a significant increase in the number of NADPH-d-reactive neurons in ipsilateral and contralateral intermediate (lamina VII; 17.62 ± 2.7 and 20.67 ± 13.3) and medial (lamina VIII; 7.3 ± 1.9 and 6.0 ± 2.1 respectively) zones of the ventral horns. However, a clear decline of the reactive cells was recorded on the ipsilateral side within the area around the central canal (lamina X). An increase in the NADPH-d reactivity within the ventral horns on both sides on the spinal cord and the induction of such reactivity (contralaterally) in large multipolar neurons localized in the dorsal part of the intermediate zone were revealed in cats with unilateral acute muscle inflammation. It is hypothesized, that during acute myositis, plastic changes in different layers of the dorsal and ventral horns activate the processes of disinhibition due to an increase in the number of NOS-containing/NADPH-d-reactive neurons in the spinal gray matter.

[Influence of intranasal administration of dopamine on realization of cognitive processes and locomotor activity of rats during stress].

In spontanepously hypertensive rats (SHR) we studied the influence of intranasal administration of dopamine (DA) on realization of food operant conditioned reflex (OCR) and motor activity (locomotion, bars, stopping beating, grooming) in a interstimulation period in a norm and in the conditions of stressed influences. The state of sharp stress was caused by application of intensive acoustic irritation is a loud sound operating during realization ofOCR. Stress caused a brake of conditioned reflex activity, immobilization ofanimals, weakening of attention to the conditional stimulus. On a background intranasal application DA (0.15 mgs/of kg) the effect of stress on voice irritation was eliminated, not rendering brake influence on OCR and motor activity. DA via oppressing the reactions of alarm and fear strengthened the focused attention that assisted the improvement of integrative function in the concrete situation of realization of OCR.

[Characteristics of neuronal activity in nucleus accumbens in spontaneously hypertensive rats].

Spontaneously hypertensive rats (SHR) are generally considered as genetic model both for essential hypertension and attention-deficit hyperactivity syndrome. Neuroanatomical substrates and mechanisms of neural disorders in the SHR have not been elucidated. This study aimed to determine if the background impulse activity of Nucleus accumbens, core (NAc) neurons and their reactions evoked by amigdala stimulation in the SHR differ from those of normotensive Wistar rats (WR). Besides that we investigated the influence of microiontophoretic beta-adrenergic receptors agonist isoproterenol administration (5 mM solution; pH 5.0; 10-30 nA) on the NAc neuronal activity. Single unit extracellular recordings were performed under urethane anesthesia. These results showed that percentage of the NAc neurons with bursting discharge pattern of the background impulse activity is significantly (P < 0.001) greater in SHR (42%) compared to WR (13%). Also, more of the NAc neurons in the SHR (27% had cyclic fluctuations of the frequency of background activity with second period than in the WR (4%). Excitatory reactions of the NAc neurons evoked by amigdala stimulation in the SHR had more long duration. Activation of beta-adrenergic receptors under isoproterenol administration allows us to reproduce a burst type of neuronal impulsation and cyclic fluctuations of the NAc background neuronal activity in both kinds of animals. Findings obtained support the possibility that in the SHR beta-adrenergic function within the NAc is enhanced compare to control.