Time Perception Test in IntelliCage System for Preclinical Study: Linking Depression and Serotonergic Modulation.

The link between serotonergic modulation and depression is under debate; however, serotonin reuptake inhibitors (SRIs) are still the first-choice medicine in this condition. Disturbances in time perception are also reported in depression with one of the behavioral schedules used to study interval timing, differential-reinforcement-learning-of-low-rate, having been shown to have high predictive validity for an antidepressant effect. Here, we introduce an IntelliCage research protocol of an interval bisection task that allows more ecologically valid and less time-consuming rodent examination and provides an example of its use to confirm the previously reported acute effect of an SRI, clomipramine, on interval timing (increase in bisection point, D50).

The Role of the Serotonergic System in Time Perception: A Systematic Review.

Time perception is a fundamental cognitive function essential for adaptive behavior and shared across species. The neural mechanisms underlying time perception, particularly its neuromodulation, remain debated. In this review, we examined the role of the serotonergic system in time perception (at the scale of seconds and minutes), building a translational bridge between human and non-human animal studies.

Audiogenic Seizures and Social Deficits: No Aggravation Found in Krushinsky-Molodkina Rats.

Epilepsy or epileptic syndromes affect more than 70 million people, often comorbid with autism spectrum disorders (ASD). Seizures are concerned as a factor for social regression in ASD. A stepwise experimental approach to this problem requires an animal model to provoke seizures and monitor subsequent behavior.

The influence of long-term housing in enriched environment on behavior of normal rats and subjected to neonatal pro-inflammatory challenge.

It is well known that neonatal pro-inflammatory challenge (NPC) acquire a predisposition to the development of a number of neuropsychiatric diseases: depression, anxiety disorders, autism, attention deficit hyperactivity disorder. Symptoms of these diseases can manifest themselves in adulthood and adolescent after repeated exposure to negative influences. Preventing the development of the negative consequences of NPC is one of the main tasks for researchers.

Acute and Chronic Lipopolysaccharide-Induced Stress Changes Expression of Proinflammatory Cytokine Genes in the Rat Brain Region-Specifically and Affects Learning and Memory.

Goal of the current work was to conduct comparative analysis of the effects of acute and chronic lipopolysaccharide-induced stress on the behavior of rats in the Morris water maze test and on expression of mRNA of proinflammatory cytokines and BDNF in different brain structures. Relevance of this study is related to poor understanding of the effects of acute and chronic stress on manifestation of cognitive brain functions, as well as ambiguity of the literature data on the effects of both stresses on hypothalamic pituitary axis and expression of the proinflammatory cytokine genes. In the experiments with rats, acute lipopolysaccharide (LPS)-induced stress improved learning in the Morris water maze.

Effects of Social Isolation on the Development of Anxiety and Depression-Like Behavior in Model Experiments in Animals.

This review describes the role of social isolation in the development of anxiety and depression-like behavior in rodents. The duration of social isolation, age from onset of social isolation, sex, species, and strain of animals, the nature of the model used, and other factors have been shown to have influences. The molecular-cellular mechanisms of development of anxiety and depression-like behavior under the influence of social isolation and the roles of the HHAS, oxidative and nitrosative stress, neuroinflammation, BDNF, neurogenesis, synaptic plasticity, as well as monoamines in these mechanisms are discussed.

Intrahippocampal Adeno-Associated Virus-Mediated Overexpression of Nerve Growth Factor Reverses 192IgG-Saporin-Induced Impairments of Hippocampal Plasticity and Behavior.

One of the aspects of Alzheimer disease is loss of cholinergic neurons in the basal forebrain, which leads to development of cognitive impairment. Here, we used a model of cholinergic deficit caused by immunotoxin 192IgG-saporin to study possible beneficial effects of adeno-associated virus (AAV)-mediated overexpression of nerve growth factor (NGF) in the hippocampus of rats with cholinergic deficit. Suspension of recombinant AAV carrying control cassette or cassette with NGF was injected into both hippocampi of control rats or rats with cholinergic deficit induced by intraseptal injection of 192IgG-saporin.

Intracerebroventricular Administration of IgG-Saporin Alters Expression of Microglia-Associated Genes in the Dorsal But Not Ventral Hippocampus.

One of important aspects of development of Alzheimer's disease is degeneration of septal cholinergic neurons that innervate the hippocampus. We took advantage of widely used model of cholinergic deficit in the hippocampus, intracerebroventricular administration of IgG-saporin (Ig-saporin), to analyze the postponed consequences of cholinergic deficit in different parts of the hippocampus. We studied effects of the immunotoxin on the behavior of rats and gene expression in the dorsal and ventral hippocampus using RNA-seq approach.

[Impulsive Choice Improves the Cue Memory at an 8-arms Radial Maze Learning in Rats].

At the process of learning in an 8-arm radial maze the impulsive animals found the reinforced arms and ate the pellets faster, than self-control and ambivalent rats. They committed less working memory errors at the cue memory task, though there was no difference in the rate of learning and a number of errors of reference memory in animals of different groups. During reversion learning at the change of reinforced arms on unre- inforced, and vice versa, the impulsive animals spent less time to enter into the reinforced arms compared to other groups.

[Propranolol Impairs Memory Reconsolidation at Single and Multiple Paired with Tone Painful Electrocutaneous Stimulations].

In the current paper there were used two methods for assessment of the propranolol effect on reactivated memory at reconsolidation phase--a classical pavlovian conditioning and the two-ways escape reflex. The difference between these two models was that in the first case a tone was paired with electrocutaneous painful stimulation only once, while in the second case it was applied multiply. Reminding was produced in the first case by placing the animals into the same context, whereas in the second case by application of the same amount of pairings of conditional and unconditional stimuli as it was used at the first day of learning.

[Does Impulsivity Affect a Long-term and Working Memory in rats?].

In the present paper usingthe method of delay discounting three groups of animals were discovered: a) those that at choice between immediate weak and delayed strong rewards have chosen an immediate reinforcement (high impulsive rats); b) those that were able to inhibit its own behavior and get the delayed reinforcement (low impulsive rats); and c) the rats with both types of reactions. In the water maze the different groups of rats did find a hidden platform for different time, swum various distance and with different speed. The differences however were significant only at overall comparison (for all days and trials) of the above mentioned parameters of the water maze learning.

[Effect of Agonists and Antagonists of α2 Adrenergic Receptors on Choice of Reinforcement Value in Rats with Different Levels of Impulsivity].

The influence of drugs, agonist (clonidine) and antagonist (yohimbine) of α2-adrenergic receptors 5-HT2 on the behavior of rats tested by the method of choice to the value of reinforcement was investigated. Based on the selection of a rat the pedal for immediate poor and delayed valuable reinforcement rats were divided into 3 groups. Rats, in most cases, choosing valuable delayed reinforcements were classified as low-impulsive, those who mainly chosen poor immediate reinforcement to the high-impulsive group.

[Synchronization and propagation of electrical potentials in neural networks of the brain cortex].

On the basis of the published data the scheme is proposed which explains the spread and synhronization of oscillatory activity in cortex. The main property of the neocortex is the existence of vertically oriented functional columns. Within and between the neuronal columns exist a feedforward and feedback morphological and functional connections.

[Evaluation of exploratory activity and anxiety in rats with different levels of impulsive behavior].

Rats were divided into 3 groups according to their preference for reinforcements of different values. Animals that preferred valuable but delayed reinforcement in more than 70% of cases formed as self-controlled group, less than 30% of cases formed an impulsive group, the rest formed an ambivalent group. Behavior of animals of different groups was scored for exploratory activity and anxiety in x-maze, fear-conditioning and novelty suppressed feeding.

[Effect of agonists and antagonists of 5-HT2 receptors on rats with different choice of reinforcement value].

The influence of drugs, agonist (DOI) and antagonist (ketanserin) ofserotonin receptors 5-HT2 on the behavior of rats tested by the method of choice to the value of reinforcement was investigated. Depending on their preferences in food reinforcement rats were divided into self-control (choosing more valuable, delayed reinforcement) and impulsive (low value, immediate reinforcement) groops. An hour before the test animals were administrated i.

[Effect of D1/D2 dopamine receptors agonists and antagonists on rats with different choice of reinforcement value].

The effects of D1/D2 dopamine receptors agonist (SKF, TNPA) and antagonist (SCH 23390, raclopride) on rat behavior, associated with the choice of the reinforcement value were investigated. Animals were divided into two typological groups--group of impulsive, choosing low-value immediate reinforcement, and self-control group, preferring valuable delayed reinforcement (paradigm delay-discount). The results showed that i.

[Effect of the selective ligands 5-HT(1A) receptors administration on the impulsive and self-control behavior in rats].

The influence of drugs, agonist and antagonist of serotonin receptors 5-HT(1A) on the behavior of rats tested by the method of choice to the value of reinforcement was investigated. Depending on their preferences in food reinforcement rats were divided into self-monitoring (choosing more valuable, delayed reinforcement) and impulsive (low value, immediate reinforcement). An hour before the test animals were administrated i.

[Effects of blockade of dopaminergic D1/D2 receptors on behavior of impulsive and self-controlled rats].

Selective antagonists of D1 and D2 receptors (SCH 23 390 and raclopride respectively) were injected to rats divided on the basis of preliminary experiments into groups of"self-controlled" (preference of valuable but delayed reinforcement) and "impulsive" (choice of less valuable but immediate reinforcement) animals. Number of omissions of reactions and their latencies were recorded. In "self-controlled" rats, both drugs increased the number of reactions for less valuable immediate reinforcement, i.

[Differences in behavior of impulsive and self-controlled rats in the open-field and light-dark tests].

The aim of the study was to reveal the relationship between impulsive behavior in rats, on the one hand, and locomotor activity and emotionality on the other hand. Rats were divided into groups according to their preference for reinforcements of different values. Animals that preferred valuable but delayed reinforcement in more than 60% of cases formed a self-controlled group, whereas rats that selected poor but immediate reinforcements in more than 60% of the cases were considered as impulsive.

[Remote control of the goal-directed behavior of freely moving rats by telestimulation of the rewarding brain structures].

The procedures are described that make it possible to train laboratory rats for remote control of their goal-directed behavior in open environments by telestimulation of rewarding brain structures. Rats were implanted electrodes in the lateral hypothalamus and lateral preoptic area. A week after surgery, rats were placed in an operant chamber and given electrical stimulation of increasing/decreasing intensity to each location to determine the most suitable site/hemisphere for reward delivery as well as the optimal stimulation parameters and the thresholds of behavioral reactions elicited.

[Investigation of behavior of "impulsive" and "self-controlled" animals by the method of "emotional resonance"].

Rats divided into groups of "impulsive" and "self-controlled" animals by their preference of either high valuable but delayed or a low valuable but immediate food reward were studied by the method of "emotional resonance". It was shown that all rats of the "self-controlled" group choosing a high valuable although delayed reinforcement did not escape the defensive signals of another animal of the same species and for the most part of the trial time preferred to stay in the dark "house". The majority of animals belonging to the "impulsive" group (80%) spent more than a half of the time of the experiment in the bright compartment and thus saved a partner from electrical stimulation.

[Study of impulsivity in rats under conditions of choice between food reinforcements of different values].

Rat behavior was studied under conditions "with the right to choose the values of reinforcements depending on the time delay of its receipt". Rats were placed in a chamber equipped with two retractable pedals, pressing one of which provided a small portion of food (1 pellet), and pressing the second pedal was followed by the delivery of more valuable food (4 pellets), but delayed reinforcement. Rats preferring small reinforcement without the delay were considered as "impulsive" and rats choosing more valuable delayed reinforcement were considered as "self-controlling".

Comparative analysis of spike activity of neurons in hippocampal field CA1 and CA3 in rats of different typological groups on exposure to emotional stimuli.

Spike activity from neurons in hippocampal field CA1 and CA3 was compared in rats avoiding ("altruists," group A) and not avoiding ("egoists," group E) the cries of a "victim" partner on testing using the emotional resonance method. Neuron discharge frequencies were compared in animals in the state of starvation, after satiation, and on exposure to emotionally positive and negative intracerebral electrical stimuli. These studies showed that hippocampal field CA1 was dominated by cells increasing their spike frequencies after satisfaction of the food motivation, while in field CA3, conversely, most cells decreased activity after eating.

[Comparative analysis of neuronal impulse activity in the CA1 and CA3 hippocampal fields in various typological groups of rats under exposure to emotional stimuli].

Hippocampal unit activity in the right and left CA1 and CA3 fields was studied in rats divided in two groups by the method of "emotional resonance": the animals which did ("A") and did not stop ("E") crying of a partner rat. The rate of neuronal firing was studied in the state of hunger, satiation, and under exposure to intracranial electrical stimulation of the emotional positive and negative structures of the brain. It was shown that units increasing their activity after satiation prevailed in the CA1 field, whereas, in the CA3 field, the majority of neurons decreased the firing rate under these conditions.

[Impulse activity in the CA1 field in animals of various typological groups exposed to emotional stimuli].

Hippocampal unit activity in the right and left CA1 fields was studied in rats divided in two groups by the method of "emotional resonance": the animals that did (A) and did not stop (E) crying of rat-partner. The rate of neuron firing was studied in the state of hunger, satiation, and under exposure to intracranial electrical stimulation of the emotional positive and negative structures of the brain. It was shown that the intracranial stimulation, especially positive, increased the rate of firing.