Enhancement of the Post-training Cholinergic Tone Antagonizes the Impairment of Retention Induced by a Nitric Oxide Synthase Inhibitor in Mice

The present experiments examined the role of the central cholinergic system in the memory impairment induced by post-training administration of a nitric oxide synthase (NOS) inhibitor in mice. Male Swiss mice received a one-trial inhibitory avoidance training (0.8 mA, 50 Hz, 1-s footshock) followed immediately by an ip injection of the NOS inhibitor -N^G-nitroarginine methyl ester ( -NAME; 100 mg/kg). Retention (cut-off time, 300 s) was tested 48 h after training. The administration of -NAME results in memory impairment for the inhibitory avoidance task. The effects of -NAME (100 mg/kg, ip) on retention were reversed in a dose-related manner by the centrally acting anticholinesterase physostigmine (35, 70, or 150 μg/kg, sc) administered 30 min after the NOS inhibitor. Further, -NAME (100 mg/kg, ip)-induced memory impairment was completely antagonized by the centrally acting muscarinic cholinergic agonist oxotremorine (OTM; 25, 50, or 100 μg/kg, sc) when given 30 min after -NAME. The peripherally acting anticholinesterase neostigmine (150 μg/kg, sc) did not modify the memory-impairing effects of -NAME. These findings suggest that the memory impairment following post-training administration of a NOS inhibitor is mediated, at least in part, by a reduction of the activity of central muscarinic cholinergic mechanisms and are consistent with our previous view that nitric oxide may be involved in post-training neural processes underlying the storage of newly acquired information.     

Effects of Posttraining Administration of Glucose on Retention of a Habituation Response in Mice: Participation of a Central Cholinergic Mechanism

Male Swiss mice were allowed to explore a novel environment, provided by an open-field activity chamber, for 10 min. The procedure was repeated twice with a 24-h interval. The difference in the exploratory activity between the first (training) and the second (testing) exposures to the chamber was taken as an index of retention of this habituation task. Posttraining intraperitoneal administration of glucose (10–300 mg/kg) enhanced retention in a dose-related manner, although only the dose of 30 mg/kg of glucose produced significant effects. Thus, the dose–response curve adopted an inverted U-shaped form. Glucose (30 mg/kg) given to untrained mice did not modify their exploratory performance when recorded 24 h later. The effects of glucose on retention were time-dependent, suggesting an action on memory storage. The memory-improving actions of glucose were prevented by the simultaneous administration of both the central acting muscarinic cholinergic antagonist atropine (0.5 mg/kg) and by the central acting nicotinic cholinergic antagonist mecamylamine (5 mg/kg). In contrast, neither methylatropine (0.5 mg/kg), a peripherally acting muscarinic receptor blocker, nor hexamethonium (5 mg/kg), a peripherally acting nicotinic receptor blocker, prevented the effects of glucose on retention. Low subeffective doses of glucose (10 mg/kg) and the central anticholinesterase physostigmine (35 μg/kg), but not neostigmine (35 μg/kg), given together, act synergistically and facilitated retention. We suggest that glucose modulates memory storage of one form of learning elicited by stimuli repeatedly presented without reinforcement, probably through an enhancement of brain acetylcholine synthesis and/or its release.     

Aptitude Tests: Can We Predict Their Future?

Garcia, J. The Logic and Limits of Mental Aptitude Testing. American Psychologist, 1981, 36, 1172–1180. Hargadon, F. Tests and College Admissions. American Psychologist, 1981, 36, 1112–1119.     

Visual symmetry recognition by pigeons

Summary Pigeons learned to discriminate a large number of bilateral symmetric and asymmetric visual patterns successively projected on the pecking-key of an operant conditioning chamber. Responses to the positive stimuli were reinforced according to a variable interval schedule. Once acquisition was complete generalization trials, involving sets of new stimuli, were instituted under extinction. The birds classified these novel test stimuli with high accuracy throughout, according to their symmetry or asymmetry. Their performance was not disturbed by sets of test stimuli whose geometrical style differed considerably from the training stimuli. Pigeons were even able to discriminate when only allowed the use of one eye. The generalization series were partly designed to test some classical symmetry recognition theories. None was found to be adequate. Subsidiary experiments suggested that most pigeons have a slight spontaneous preference for asymmetric patterns and that symmetry/asymmetry differences can aid pattern discrimination learning at an early stage. It is concluded that pigeons, much like humans, can discriminate bilaterally symmetric from non-symmetric visual forms in a concept-like, generalizing way. The ontogenetic and phylogenetic development of this competence is considered. A novel symmetry recognition hypothesis based on spatial frequency analysis and neuronal feature-detector considerations is proposed.     

Demonstration of an aftereffect occurring in the tactile-kinesthetic domain

Summary The aim of this work is the demonstration of a tactile-kinesthetic aftereffect. A sequence of stimuli was offered to adult subjects whose task was to compare two weights presented simultaneously to both hands by means of a Piéron gravimeter. In Experiment 1 the inspection stimuli consisted of two successive presentations of unequal weights for a period of 2 × 10 s. The test stimuli consisted of two equal weights rapidly following an inspection stimulus. Control stimuli consisting of two equal weights not preceded by an inspection stimulus were interspersed in the sequence. The results obtained confirm the existence of a contrast effect after presentation of an inspection stimulus. In Experiment 2 the inspection stimuli consisted of a single presentation of two unequal weights for a period of 20 s. The results confirm those of the first experiment and provide data enabling the contrast effect obtained to be interpreted as a Köhler-type aftereffect. In order to avoid confusion with the kinesthetic-figural aftereffect, we propose to call the effect demonstrated here the Gravimetric Aftereffect.     

多媒体环境下图文的具体程度对学习效果的影响

让70名小学生在多媒体环境中学习概念材料与原理材料,以探讨文本和图画材料的具体程度对学习迁移效果的影响。结果表明,在概念材料上,文本与图画的具体性程度之间存在显著的交互作用,即在具体图水平上,具体文的迁移成绩显著高于抽象文;在抽象图水平上,具体文的迁移成绩低于抽象文,但没有达到显著性水平。在原理材料上,文本与图画的具体性程度之间也存在显著的交互作用,但交互作用的方式与概念材料相反,即在具体图水平上,具体文的迁移成绩显著低于抽象文;在抽象图水平上,具体文的迁移成绩高于抽象文,但没有达到显著水平。     

Family and food variables that influence life satisfaction of mother-father-adolescent triads in a South American country

This study explored the influence of each family member’s life satisfaction on the other family members’ life satisfaction in mother-father-adolescent triads. We also explored the influence of each family member’s satisfaction with food-related life and family life on their own life satisfaction (LS) as well as on the other family members’ LS in mother-father-adolescent triads. The influence of family eating habits, food-related parenting practices used by each parent and sociodemographic characteristics on each family member’s LS were also explored. A survey was applied to a sample of 300 two-parent families with one child between 10 and 17 years of age in Temuco, Chile. The questionnaire included the Satisfaction with Life Scale, Satisfaction with Food-related Life scale, Satisfaction with Family Life scale, Adapted Healthy Eating Index, Family Food Behavior Survey and Family Eating Habits Questionnaire. Frequency and sources of family meals as well as sociodemographic characteristics were also consulted. Three multivariate ordinal logit models were proposed, with the dependent variable LS in the three subsamples: mothers, fathers and adolescents. The three logit models were significant, but differed in the explanatory variables. Mothers’ LS was influenced by their children’s LS and vice versa. Mothers’ LS was positively influenced by both their own satisfaction with family life and the fathers’ satisfaction with family life and vice versa. Children’s LS was also positively influenced by their own satisfaction with food-related and family life. Both parents’ LS was influenced by eating habits, food-related parenting practices and sociodemographic characteristics, but in different ways. Therefore, different interventions should be implemented to improve each family member’s life satisfaction.

     

Economic optimization by compromise programming: The joint production model

In a basic microeconomic model (joint production and consumer's utility curves) three key optima appear: the best technological mix, the maximum profit point and the consumer's utility optimum. Compromise analysis can help to clarify their connections. This paper and other recent research attempt to specify the conditions which guarantee that these three optima coincide. Thus compromise programming becomes a valuable surrogate of economic optimization.