Independence of first- and second-order memories in newborn rabbits.

WOS:000291649400006International audienceThe mammary pheromone promotes the acquisition of novel odorants (CS1) in newborn rabbits. Here, experiments pinpoint that CS1 becomes able to support neonatal learning of other odorants (CS2). We therefore evaluated whether these first- and second-order memories remained dependent after reactivation. Amnesia induced after CS2 recall selectively blocked this memory, when recall and amnesia of CS1 left the souvenir of CS2 safe; this finding partially differed from results obtained in adult mammals. Thus, in this model of neonatal appetitive odor learning, second-order memory seems to depend on first-order memory for its formation but not for its maintenance

Consolidation, rappel, réactivation

Summary Facts concerning experimental amnesia are reviewed within the framework of the consolidation hypothesis versus the retrieval hypothesis. Recent experiments with reactivation treatment are also presented. From these two categories of data it appears that : 1) Most memory deficits can be interpreted as a retrieval failure ; 2) Engram sensitivity is not an exclusive property of the consolidation period. This suggests a similarity between mnesic processes involved just after acquisition, during reactivation and for restitution.Résumé Après un retour sur l'hypothèse de la consolidation et sur ses implications, nous présentons les arguments qui amènent à l'hypothèse du rappel. Puis nous passons en reçue les expériences récentes concernant la réactivation. Des faits expérimentaux exposés, il ressort : 1) Que la plupart des perturbations mnésiques peuvent être interprétées par un défaut du rappel ; 2) Que la phase de labilité de la trace mnésique n'est pas une propriété exclusive de la période de consolidation. Ceci nous amène à nous interroger sur la similitude qui peut exister entre les processus mnésiques prenant place après l'acquisition, à l'occasion d'une réactivation, ou au moment de la restitution.Hars Bernard. Consolidation, rappel, réactivation. In: L'année psychologique. 1980 vol. 80, n°1. pp. 237-265

Dynamique de la mémoire au cours du développement post-natal, étude chez le raton

LE KREMLIN-B.- PARIS 11-BU Méd (940432101) / SudocSudocFranceF

Pheromone-induced olfactory memory in newborn rabbits: Involvement of consolidation and reconsolidation processes

International audienceMammary pheromone (MP)-induced odor memory is a new model of appetitive memory functioning early in a mammal, the newborn rabbit. Some properties of this associative memory are analyzed by the use of anisomycin as an amnesic agent. Long-term memory (LTM) was impaired by anisomycin delivered immediately, but not 4 h after either acquisition or reactivation. Thus, the results suggest that this form of neonatal memory requires both consolidation and reconsolidation. By extending these notions to appetitive memory, the results reveal that consolidation and reconsolidation processes are characteristics of associative memories of positive events not only in the adult, but also in the newborn

The temporal dynamics of consolidation and reconsolidation decrease during postnatal development

The temporal dynamics of consolidation and reconsolidation of taste/odor aversion memory are evaluated during rat pup growth at postnatal days 3, 10, and 18. This is assessed through the temporal gradients of efficacy of a protein synthesis inhibitor (anisomycin) in inducing amnesia after either acquisition (consolidation) or reactivation (reconsolidation). The results show a progressive reduction with age of the delay during which the inhibitor is able to induce amnesia. Control experiments rule out a reduction of anisomycin efficacy due to blood brain barrier growth or decrease in protein synthesis inhibition. Thus, these results present the first evidence that the protein synthesis-dependent phase of memory stabilization requires less time with age. This decrease occurs in parallel for consolidation and reconsolidation. Such changes in the dynamics of memory processing could contribute to the cognitive improvement associated with development

A pheromone to behave, a pheromone to learn: the rabbit mammary pheromone.

International audienceBirth is part of a continuum and is a major developmental change. Newborns need to adapt rapidly to the environment in terms of physiology and behaviour, and ability to locate the maternal source of milk is vital. Mechanisms have evolved resulting in the emission of olfactory cues by the mother and the processing of these cues by the young. Here, we focus on some sensory, cognitive and behavioural strategies developed by the European rabbit (Oryctolagus cuniculus) that optimize the early development of offspring. In this species, chemosensory communication between the mother and young plays a critical role in eliciting adaptive neonatal responses. In particular, lactating females release a molecule, the mammary pheromone, which has several functional impacts. It triggers orocephalic responses involved in the quick localization of nipples and sucking. Moreover, this unconditioned signal promotes rapid appetitive learning of novel odorants, acting as a potent organizer of neonatal cognition. The mammary-pheromone-induced odour memory requires consolidation/reconsolidation processes to be maintained in the long term. Finally, as this mode of conditioning also promotes learning of mixtures of odorants, it supports investigations related to the capacity of neonatal olfaction to extract biological value from the complex environment