The impact of the new derivative of nicotinic acid with anti-hypoxic activity on the functions of the central nervous system

The aim of the work was to study the effect of the complex compound of nicotine acid with antihypoxic activity under the code πQ-1043 on the function of the central nervous system. The experiments were performed on male mice of the SHR line. Influence of the compound on the function of the central nervous system was evaluated in the tests “open field”, conditioned-defense reflex of avoidance and corazole seizures. It was found that the compound πQ-1043 at a dose of 25 mg/kg increases emotional reactivity and reduces the coefficient of mobility of mice in the “open field” test, increases the latent time of the conditionally defensive reflex of avoidance, inhibits the development of seizures and increases the life expectancy of animals after administration of corazole. Such changes in the studied parameters indicate that the compound πQ-1043 has a depressing effect on the central nervous system function. It is assumed that the identified effect may be one of the components in the mechanism of antihypoxic action of the compound.

Preprint: Using the Threat Probability Task to assess anxiety and fear during uncertain and certain threat

Fear of certain threat and anxiety about uncertain threat are distinct emotions with unique behavioral, cognitive-attentional, and neuroanatomical components. Both fear and anxiety can be studied in the laboratory by measuring the potentiation of the startle reflex. The startle reflex is a defensive reflex that is potentiated when an organism is threatened and the need for defense is high. The startle reflex is assessed via electromyography (EMG) in the orbicularis oculi muscle elicited by brief, intense, bursts of acoustic white noise (i.e., “startle probes”). Startle potentiation is calculated as the increase in startle response magnitude during presentation of sets of visual threat cues that signal delivery of mild electric shock relative to sets of matched cues that signal the absence of shock (no-threat cues). In the Threat Probability Task, fear is measured via startle potentiation to high probability (100% cue-contingent shock; certain) threat cues whereas anxiety is measured via startle potentiation to low probability (20% cue-contingent shock; uncertain) threat cues. Measurement of startle potentiation during the Threat Probability Task provides an objective and easily implemented alternative to assessment of negative affect via self-report or other methods (e.g., neuroimaging) that may be inappropriate or impractical for some researchers. Startle potentiation has been studied rigorously in both animals (e.g., rodents, non-human primate) and humans which facilitates animal-to-human translational research. Startle potentiation during certain and uncertain threat provides an objective measure of negative affective and distinct emotional states (fear, anxiety) to use in research on psychopathology, substance use/abuse and broadly in affective science. As such, it has been used extensively by clinical scientists interested in psychopathology etiology and by affective scientists interested in individual differences in emotion.

Defensive reflexes in people with pain – a biomarker of the need to protect? A meta-analytical systematic review

Upregulation of defensive reflexes such as the nociceptive flexion reflex (NFR) has been attributed to sensitisation of peripheral and spinal nociceptors and is often considered biomarkers of pain. Experimental modulation of defensive reflexes raises the possibility that they might be better conceptualised as markers of descending cognitive control. Despite strongly held views on both sides and several narrative reviews, there has been no attempt to evaluate the evidence in a systematic manner. We undertook a meta-analytical systematic review of the extant English-language literature from inception. Thirty-six studies satisfied our a priori criteria. Seventeen were included in the meta-analysis. Reflexive threshold was lower in people with clinical pain than it was in pain-free controls, but reflex size, latency, and duration were unaffected. The pattern of difference was not consistent with sensitisation of nociceptive neurones, as these changes were not isolated to the affected body part but was more consistent with top-down cognitive control reflective of heightened protection of body tissue. The pattern of modulation is dependent on potentially complex evaluative mechanisms. We offer recommendations for future investigations and suggest that defensive reflex threshold may reflect a biomarker of a broader psychological construct related to bodily protection, rather than sensitisation of primary nociceptors, spinal nociceptors, or pain.

RESTRAIN OF FEAR: PARTICIPATION OF GABA NEUROTRANSMITTER SYSTEM

In experiences on rats in the conditions of free behavior at development of a conditioned of passive avoidanсe reflex (the first series) and a defensive reflex and a conditional inhibition (the second series) it is revealed, and elaboration of internal inhibition and Phenibut – a nonspecific agonist of GAMKA and GAMKB receptors cause in experimental animals weakening of freezing arising in a dangerous situation, and a disinhibition of research behavior. Results of experiences in the accounting of data of the literature allow to assume that both factors, and elaboration of internal inhibition, and Phenibut weaken freezing – the phenomenon used in experiments as a biological analog of fear, owing to increase of level of activity of the GABA neurotransmitter system of a brain. Key words: training, freezing, fear, inhibition, disinhibition, GABA, Phenibut.