ABSTRACT
Learning and retention of the spatial memory were studied in mice with alternative under conditions of various experimental protocols. Visible and hidden platform acquisition in a simple model of the water maze was similarly fast both in aggressive and submissive mice, but extinction differed. Retention of the platform location preference persisted in aggressive mice in four testing trials. In submissive mice, extiction of the spatial memory was accompanied with a prolongation of search with parallel production of episodes of "passive drift". Differences in spatial learning between aggressive and submissive mice were revealed in a water maze complicated with partitions. In this case, aggressors were able to learn the position of a hidden platform (in contrast to submissive mice with the dominant response of "passive drift"). During testing the response, aggressive mice longer retained the spatial preference without extinction.
Subject(s)
Aggression , Dominance-Subordination , Maze Learning , Retention, Psychology , Animals , Male , Mice , Mice, Inbred C57BL , OrientationABSTRACT
The effects of an agonist (D-cycloserine) and an antagonist (dizocilpine) of N-methyl-D-aspartate (NMDA) receptors on the learning and extinction of a conditioned passive avoidance response were studied in mice with low, intermediate, and high levels of anxiety. In intermediate-anxiety mice, D-cycloserine (30 mg/kg) had no effect on learning but accelerated extinction, while dizocilpine (0.15 mg/kg) degraded acquisition of the reflex but delayed extinction. In high-anxiety mice, with good learning and no extinction, D-cycloserine had no effect, while dizocilpine decreased learning and facilitated retention of performance of the memory trace at the ongoing level in conditions promoting extinction. In low-anxiety mice, D-cycloserine degraded learning and accelerated extinction, while dizocilpine completely blocked learning and the retention of the passive avoidance response.
Subject(s)
Anxiety/metabolism , Avoidance Learning/physiology , Conditioning, Classical/physiology , Extinction, Psychological/physiology , Receptors, N-Methyl-D-Aspartate/metabolism , Animals , Antimetabolites/pharmacology , Anxiety/physiopathology , Avoidance Learning/drug effects , Conditioning, Classical/drug effects , Cycloserine/pharmacology , Disease Models, Animal , Dizocilpine Maleate/pharmacology , Excitatory Amino Acid Antagonists/pharmacology , Extinction, Psychological/drug effects , Male , Mice , Mice, Inbred C57BL , Receptors, N-Methyl-D-Aspartate/agonists , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Severity of Illness IndexABSTRACT
The relationship between the extinction of a conditioned passive avoidance reflex and the initial anxiety level was studied in mice. The time spent in the open arms of an elevated cross maze was used to classify the mice into high-, intermediate-and low-anxiety individuals. Each level of anxiety was found to correspond to a defined extinction dynamic. Highly anxious mice were characterized by the absence of extinction of the conditioned passive avoidance reflex and stability of good reproduction of the memory trace on testing to as long as 15 days. In intermediately anxious individuals, a deficit in performance of the avoidance reflex appeared from day 7 of extinction. In low-anxiety mice, memory trace reproduction deteriorated from test day 11.
Subject(s)
Anxiety/physiopathology , Avoidance Learning/physiology , Conditioning, Operant/physiology , Extinction, Psychological/physiology , Animals , Behavior, Animal , Escape Reaction/physiology , Male , Mice , Mice, Inbred C57BLABSTRACT
It was shown that injections of NMDA receptor antagonist dizocilpine and neurosteroid dehydroepiandrosterone sulfate (DHEAS) and sequential injections of these substances had different effects on learning and extinction of passive avoidance in aggressive and submissive mice. In aggressive mice, dizocilpine impaired and DHEAS did not change learning and retention. However, being injected after dizocilpine, DHEAS blocked the defect of memory trace retrieval induced by dizocilpine. In submissive mice, dizocilpine impaired learning and prolonged extinction of the learned habit. Injection of DHEAS prolonged the extinction in a similar way. Under conditions of sequential injections, DHEAS did not change the suppressive effect of dizocilpine on learning and was not effective in prolongation of extinction.
Subject(s)
Aggression , Dehydroepiandrosterone Sulfate/pharmacology , Dizocilpine Maleate/pharmacology , Excitatory Amino Acid Antagonists/pharmacology , Extinction, Psychological , Memory/drug effects , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Animals , Avoidance Learning/drug effects , Male , Mice , Mice, Inbred C57BL , Retention, PsychologyABSTRACT
The effects of dehydroepiandrosterone sulfate (DHEAS) on the extinction of passive avoidance was studied on C57Bl/6J mice with aggressive and submissive behavioral stereotypes. Administered in a single dose 30 mg/kg one day or one hour before training, DHEAS selectively blocked the extinction of the conditioned habit in submissive mice, thus favoring its retrieval. The probable mechanism of this phenomenon can be related to a decrease in the level of inhibiting control in the GABAergic system.
Subject(s)
Aggression , Avoidance Learning/drug effects , Conditioning, Classical/drug effects , Dehydroepiandrosterone Sulfate/pharmacology , Escape Reaction/drug effects , Extinction, Psychological/drug effects , Animals , Male , Mice , Mice, Inbred C57BLABSTRACT
Influence of agonist (D-cycloserine) and antagonist (dizocilpine) N-methyl-D-aspartate receptors on learning and extinction of passive avoidance response in medium-, high-, and low-anxious mice was studied. In medium-anxious mice, D-cycloserine (30 mg/kg) although not changing learning accelerated development of extinction, whereas dizocilpine (0.15 mg/kg), while impairing passive avoidance learning, detained the extinction. In high-anxious mice with good retrieval of memory trace and absence of extinction, D-cycloserine was ineffective, whereas dizocilpine reduced learning and promoted retention of memory trace retrieval at the generated level on extinction. In low-anxious mice, D-cycloserine impaired learning and accelerated extinction, whereas dizocilpine completely blocked learning and retention of passive avoidance response.
Subject(s)
Anxiety/psychology , Avoidance Learning/drug effects , Extinction, Psychological/drug effects , Receptors, N-Methyl-D-Aspartate/agonists , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Animals , Anxiety/metabolism , Cycloserine/pharmacology , Dizocilpine Maleate/pharmacology , Male , Maze Learning/drug effects , Mice , Mice, Inbred C57BL , Reaction Time/drug effectsABSTRACT
We report here the results obtained from comparative analysis of learning and the dynamics of extinction of a conditioned passive avoidance response in mice with genetic knockout of monoamine oxidase A (MAO A) and the progenitor line C3H. Mice of both lines acquired the conditioned passive avoidance reaction efficiently. Mice with genetic knockout of MAO A were characterized by prolonged retention of reproduction of the memory trace, as compared with rapid extinction in C3H mice. Smaller numbers of transfers, and vertical rearings on days 7-13 and the numbers of glances into and rom the dark sector on days 11-13 of extinction in MAO A-knockout mice appear to reflect their more marked fear reactions when confronted with the "dangerous" sector, along with increased anxiety, these facilitating longer-lasting retention of the memory trace.
Subject(s)
Avoidance Learning/physiology , Escape Reaction/physiology , Extinction, Psychological/physiology , Monoamine Oxidase/deficiency , Analysis of Variance , Animals , Behavior, Animal , Mice , Mice, Inbred C3H , Mice, Knockout , Monoamine Oxidase/genetics , Retention, Psychology/physiologyABSTRACT
The analysis of a behaviour and memory of mice with depressive state is conducted. The mice with "behavioral despair" obtained by forced swimming and mice with submissive stereotype generated by 20 confrontations were used. They were characterized by increased anxiety and reduced exploratory activity in tests of the elevated plus-maze and light/dark apparatus. It is shown that for want of behavioral differences in manifestation of a depressive state the process of extinction was opposite. Mice with "behavioral despair" revealed retention of a high level of memory trace retrieval down to the 21st day of testing reflecting essential delay of extinction. Submissive mice displayed fast extinction begining with the 5th day of testing.
Subject(s)
Avoidance Learning , Behavior, Animal , Depression/psychology , Extinction, Psychological , Memory , Animals , Male , Mice , Mice, Inbred C57BL , Retention, PsychologyABSTRACT
The dependence of the passive avoidance extinction from a level of mice initial anxiety is investigated. Mice were classified as high-, medium- and low-anxious by time spent in the open area of the elevated plus-maze. It is revealed that to each from levels of anxiety there corresponds certain dynamics of extinction. The high-anxious mice are characterized absence of the passive avoidance extinction and stability of good retrieval of memory trace for want of testing down to 15 days. At medium-anxious mice the deficit of avoidance habit performance developed since the 7th day of extinction. At low-anxious mice since the 11th day of testing the deterioration of retrieval was observed.
Subject(s)
Anxiety/psychology , Avoidance Learning/physiology , Conditioning, Classical/physiology , Extinction, Psychological/physiology , Animals , Male , Mice , Mice, Inbred C57BLABSTRACT
The passive avoidance learning and memory trace retention in mice lacking monoamine oxidase A (MAO A) and control C3H strain were analyzed. It is shown that mice of both strains were well the passive avoidance learners. A delay of the memory trace extinction was found in lacking MAO A mice as compared with control C3H strain. Mice with a genetic MAO A knockout showed decreased amounts of transitions, rearings, looking to a dark compartment and appearing from it. These findings seem to reflect more expressed fear reaction to a dangerous compartment and increased anxiety promoting longer retention of memory trace on a high level of retrieval.
