Facilitation of taste memory acquisition by experiencing previous novel taste is protein-synthesis dependent

Merhav, Maayan; Rosenblum, Kobi

doi:10.1101/lm.986008

Cited by 58 publications

(57 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Local microinjection of protein synthesis inhibitor into the gustatory cortex before or just after acquisition attenuated long-but not short-term taste memory (Rosenblum et al 1993;Houpt and Berlin 1998;Merhav and Rosenblum 2008). This indicates that protein synthesis inhibitors did not affect normal neuronal function in the cortex but attenuates specifically memory consolidation.…”

Section: Discussionmentioning

confidence: 92%

“…We found that eEF2K ki mice showed the same natural aversion to quinine (98.4 + 0.7%, n ¼ 8) as the WT (95. In order to test the hypothesis that taste memory per se, i.e., incidental taste memory, is impaired in the ki mice, we examined the reduction in neophobia by using saccharin as a novel taste (Merhav and Rosenblum 2008). No differences in aversion index were found during four consecutive days following the first taste exposure (Fig.…”

Section: Generating Eef2k Ki Micementioning

confidence: 99%

See 1 more Smart Citation

Impaired associative taste learning and abnormal brain activation in kinase-defective eEF2K mice

Gildish¹,

Manor²,

David³

et al. 2012

Learn. Mem.

Self Cite

View full text Add to dashboard Cite

Memory consolidation is defined temporally based on pharmacological interventions such as inhibitors of mRNA translation (molecular consolidation) or post-acquisition deactivation of specific brain regions (systems level consolidation). However, the relationship between molecular and systems consolidation are poorly understood. Molecular consolidation mechanisms involved in translation initiation and elongation have previously been studied in the cortex using taste-learning paradigms. For example, the levels of phosphorylation of eukaryotic elongation factor 2 (eEF2) were found to be correlated with taste learning in the gustatory cortex (GC), minutes following learning. In order to isolate the role of the eEF2 phosphorylation state at Thr-56 in both molecular and system consolidation, we analyzed cortical-dependent taste learning in eEF2K (the only known kinase for eEF2) ki mice, which exhibit reduced levels of eEF2 phosphorylation but normal levels of eEF2 and eEF2K. These mice exhibit clear attenuation of cortical-dependent associative, but not of incidental, taste learning. In order to gain a better understanding of the underlying mechanisms, we compared brain activity as measured by MEMRI (manganese-enhanced magnetic resonance imaging) between eEF2K ki mice and WT mice during conditioned taste aversion (CTA) learning and observed clear differences between the two but saw no differences under basal conditions. Our results demonstrate that adequate levels of phosphorylation of eEF2 are essential for cortical-dependent associative learning and suggest that malfunction of memory processing at the systems level underlies this associative memory impairment.

show abstract

Section: Discussionmentioning

confidence: 92%

Section: Generating Eef2k Ki Micementioning

confidence: 99%

Impaired associative taste learning and abnormal brain activation in kinase-defective eEF2K mice

Gildish¹,

Manor²,

David³

et al. 2012

Learn. Mem.

Self Cite

View full text Add to dashboard Cite

show abstract

“…2A). Like in other studies with other newborn or adult mammals (Davis and Squire 1984;Gruest et al 2004;Desgranges et al 2008;Languille et al 2008;Merhav and Rosenblum 2008) our present and previous results support the fact that the blocking effect of AN in newborn rabbits is a real amnesia and not an aversive effect (Coureaud et al 2009a. Thus, the amnesia of odorant A did not appear disruptive to the memory of odorant B. Reciprocally, 15 pups exposed to A+B, conditioned to odorant A, and reactivated with odorant B before injection of AN or saline (n ¼ 10 and 5, respectively) all responded to odorant A (x 2 , 0.1, P .…”

mentioning

confidence: 75%

Sensory preconditioning in newborn rabbits: from common to distinct odor memories

Coureaud

Tourat

2013

Learn. Mem.

View full text Add to dashboard Cite

This study evaluated whether olfactory preconditioning is functional in newborn rabbits and based on joined or independent memory of odorants. First, after exposure to odorants A+B, the conditioning of A led to high responsiveness to odorant B. Second, responsiveness to B persisted after amnesia of A. Third, preconditioning was also functional with two overlapping pairs of odorants (A+B and B+C) and amnesia of one odorant did not affect memory of the others. Thus, incidental pairing of odorants allows reinforcement of one odorant to implicitly reinforce the others, the bond then vanishes, and the memory of each element becomes independent.Although the mechanisms of first-order conditioning, based on simple association between conditioned and unconditioned stimuli (CS, US, respectively), are the focus of intense research, much less is known about higher-order conditioning in which a CS2 acquires significance by being paired with another CS (CS1) rather than a US. The CS2 is paired with CS1 before CS1+US association in sensory preconditioning, or after CS1+US association in second-order conditioning (e.g., Brogden 1939;Rescorla and Cunningham 1978;Rescorla 1980;Kehoe et al. 1981).The effectiveness of second-order conditioning has been shown recently in newborn rabbits. In this species, the mammary pheromone (MP) emitted by lactating females triggers orocephalic movements involved in neonatal localization and oral grasping of the nipples (Coureaud 2001;Schaal et al. 2003). It also promotes first-order conditioning acting as US; after a single and brief pairing with the MP, a novel odorant or mixture of odorants (CS1) becomes able to produce the conditioned grasping response 24-48 h later (Coureaud et al. , 2008Charra et al. 2013; for review, see Coureaud et al. 2010). Moreover, rabbit pups also learn to respond to CS2 when CS1+MP pairing is followed by CS1+CS2 pairing . In this second-order conditioning, amnesia of CS1 induced after recall of CS1 (by blockade of reconsolidation process) (see Coureaud et al. 2009a) leaves the CS2 memory intact . Thus, response to CS2 seems not to be based on the associative chain CS2 CS1 US/response but rather on a direct link CS2 US/response. This indicates in newborn rabbits that CS2 is independent of CS1 representation after second-order conditioning.Interestingly, behavioral differences were observed between second-order conditioning and sensory preconditioning in adult mammals. Extinction of CS1 eliminates CS2 in sensory preconditioning only (Rizley and Rescorla 1972), suggesting that this learning process is primarily mediated by associative chains (CS2 CS1 response). However, the organization of associative memory in sensory preconditioning could be different in newborns as ontogenetic differences have been reported in rodents and humans, with better abilities in such paradigms in younger organisms (for reviews, see Spear and Kucharski 1984; Rovee-Collier and Giles 2010). Until now, chemosensory preconditioning was demonstrated in newborn rats (Cheslock et al. 2003), but the...

show abstract

“…In contrast, the latent inhibition paradigm consists of pre-exposure of the animal to a novel taste, followed by CTA, which by reducing taste neophobia allows addressing taste aversion per se. Recent studies using these behavior paradigms have demonstrated that the involvement of new protein synthesis in CTA is time limited Yefet et al 2006;Merhav and Rosenblum 2008) mTOR and taste learning…”

Section: Translation Regulation In the Cortex: The Taste Casementioning

confidence: 99%

Consolidation and translation regulation: Figure 1.

et al. 2012

Self Cite

View full text Add to dashboard Cite

mRNA translation, or protein synthesis, is a major component of the transformation of the genetic code into any cellular activity. This complicated, multistep process is divided into three phases: initiation, elongation, and termination. Initiation is the step at which the ribosome is recruited to the mRNA, and is regarded as the major rate-limiting step in translation, while elongation consists of the elongation of the polypeptide chain; both steps are frequent targets for regulation, which is defined as a change in the rate of translation of an mRNA per unit time. In the normal brain, control of translation is a key mechanism for regulation of memory and synaptic plasticity consolidation, i.e., the off-line processing of acquired information. These regulation processes may differ between different brain structures or neuronal populations. Moreover, dysregulation of translation leads to pathological brain function such as memory impairment. Both normal and abnormal function of the translation machinery is believed to lead to translational up-regulation or down-regulation of a subset of mRNAs. However, the identification of these newly synthesized proteins and determination of the rates of protein synthesis or degradation taking place in different neuronal types and compartments at different time points in the brain demand new proteomic methods and system biology approaches. Here, we discuss in detail the relationship between translation regulation and memory or synaptic plasticity consolidation while focusing on a model of cortical-dependent taste learning task and hippocampal-dependent plasticity. In addition, we describe a novel systems biology perspective to better describe consolidation.

show abstract

Facilitation of taste memory acquisition by experiencing previous novel taste is protein-synthesis dependent

Cited by 58 publications

References 40 publications

Impaired associative taste learning and abnormal brain activation in kinase-defective eEF2K mice

Impaired associative taste learning and abnormal brain activation in kinase-defective eEF2K mice

Sensory preconditioning in newborn rabbits: from common to distinct odor memories

Consolidation and translation regulation: Figure 1.

Contact Info

Product

Resources

About