Moving beyond standard procedures to assess spontaneous recognition memory

Ameen‐Ali, Kamar E.; Easton, Alexander; Eacott, Madeline J.

doi:10.1016/j.neubiorev.2015.03.013

Cited by 51 publications

(45 citation statements)

References 151 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, as we previously reported, calpain-1 activation is required for TBS-induced LTP formation and for certain forms of learning, including context-dependent fear conditioning and novel object location and recognition, which are known to be hippocampus-dependent (Vogel-Ciernia and Wood 2014; Ameen-Ali et al 2015;Izquierdo et al 2016). On the other hand, calpain-1 activation does not appear to be required for tone-dependent fear conditioning, which is generally considered to be amygdala-dependent (Maren et al 2001).…”

Section: Discussionsupporting

confidence: 53%

Deleting both PHLPP1 and CANP1 rescues impairments in long-term potentiation and learning in both single knockout mice

et al. 2016

View full text Add to dashboard Cite

Calpain-1 (CANP1) has been shown to play a critical role in synaptic plasticity and learning and memory, as its deletion in mice results in impairment in theta-burst stimulation-(TBS) induced LTP and various forms of learning and memory. Likewise, PHLPP1 (aka SCOP) has also been found to participate in learning and memory, as PHLPP1 overexpression impairs hippocampus-dependent learning. We previously showed that TBS-induced LTP was associated with calpain-1 mediated truncation of PHLPP1.To better understand the roles of these 2 genes in synaptic plasticity and learning and memory, we generated a double knockout (DKO) mouse by crossing the parent strains. Surprisingly, DKO mice exhibit normal TBS-induced LTP, and the learning impairments in fear conditioning and novel object or novel location recognition were absent in the DKO mice. Moreover, TBS-induced ERK activation in field CA1 of hippocampal slices, which is impaired in both single deletion mice, was restored in the DKO mice. These results further strengthen the roles of both CANP1 and PHLPP1 in synaptic plasticity and learning and memory, and illustrate the complexities of the interactions between multiple pathways participating in synaptic plasticity.While tremendous progress has been made regarding our understanding of the molecular/cellular mechanisms underlying learning and memory, many questions regarding the roles of various signaling pathways activated during learning remain unanswered Mehta 2015;Tonegawa et al. 2015;Smolen et al. 2016). In particular, while the calcium-dependent protease, calpain, has been proposed to participate in synaptic plasticity and learning and memory many years ago (Lynch and Baudry 1984), its precise contributions are still not clearly understood. This is in part due to the existence in the brain of two major calpain isoforms, calpain-1 (aka, m-calpain) and calpain-2 (aka, m-calpain), and the lack of tools to study their respective functions in synaptic plasticity. Our previous studies have shown that long-term potentiation (LTP) elicited by theta-burst stimulation (TBS), as well as learning of hippocampus-dependent tasks were impaired in calpain-1 knockout (CANP12/2) mice Liu et al. 2016). We also found that these impairments were related to the lack of calpain-1-mediated truncation of the PH domain and Leucine-rich repeat Protein Phosphatase 1 (PHLPP1, aka suprachiasmatic nucleus oscillatory protein (SCOP)) and the resulting stimulation of the extracellular signal-regulated kinase (ERK), which plays an important role in LTP induction and in learning and memory (Wang et al. 2014). On the other hand, calpain-2 activation was found to limit the extent of potentiation in hippocampal slices and learning of hippocampus-dependent tasks (Liu et al. 2016). It has previously been reported that PHLPP1 overexpression impairs learning and memory (Shimizu et al. 2007), suggesting that PHLPP1 could also participate in synaptic plasticity (Shimizu et al. 2010).To further evaluate the role of the calpain-1-mediated truncation of PHLPP1 i...

show abstract

Section: Discussionsupporting

confidence: 53%

Deleting both PHLPP1 and CANP1 rescues impairments in long-term potentiation and learning in both single knockout mice

et al. 2016

View full text Add to dashboard Cite

show abstract

“…With the growing use of the several close variants of the spontaneous recognition memory task in rodents (Ameen-Ali et al, 2015), our results may have important prospective implications for the development of a preclinical cross-species procedure to assess specific memory functions. However, more comprehensive studies in marmosets are warranted, given that in rodents, for example, not all types of spontaneous recognition memories are affected by central cholinergic activity.…”

Section: Discussionmentioning

confidence: 95%

Scopolamine Induces Deficits in Spontaneous Object-Location Recognition and Fear-Learning in Marmoset Monkeys

et al. 2017

View full text Add to dashboard Cite

The non-selective muscarinic receptor antagonist scopolamine (SCP) induces memory deficits in both animals and humans. However, few studies have assessed the effects of amnesic agents on memory functions of marmosets – a small-bodied neotropical primate that is becoming increasingly used as a translational model for several neuropathologies. Here we assessed the effects of an acute SCP administration (0.03 mg/kg, sc) on the behavior of adult marmoset monkeys in two tasks. In the spontaneous object-location (SOL) recognition task, two identical neutral stimuli were explored on the sample trial, after which preferential exploration of the displaced versus the stationary object was analyzed on the test trial. In the fear-motivated behavior (FMB) procedure, the same subjects were submitted to an initial baseline trial, followed by an exposure period to a snake model and lastly a post-exposure trial. All trials and inter-trial intervals lasted 10 min for both tests. Results showed that on the SOL test trial, the saline group explored the displaced object significantly longer than its identical stationary counterpart, whereas SCP-treated marmosets explored both objects equivalently. In the FMB test, the saline group – but not the SCP-treated animals – spent significantly less time where the stimulus had been specifically encountered and more time being vigilant of their surroundings, compared to pre-exposure levels. Drug-related effects on general activity, overall exploration (SOL task) and behavioral response to the aversive stimulus (FMB task) were not observed. SCP thus impaired the marmosets’ short-term ability to detect changes associated with the spatial location of ethologically irrelevant (SOL task) and relevant stimuli (FMB task). Similar results have been reported in other animal species. Marmosets may thus help reduce the translational gap between pre-clinical studies and memory-associated human pathologies.

show abstract

“…In handling the animal there is likely to be some stress invoked (even very small amounts) and whilst memory is expected through exploration of novelty, there is evidence that stress produces a preference for familiar objects (neophobia) in animals (Ennaceur, 2010), meaning there is significant behavioural noise added as a result of the handling procedures. In recent years we have adopted a new approach to spontaneous recognition memory tasks (Ameen-Ali, Ameen-Ali, Easton, & Eacott, 2015;Robertson et al, 2015) which overcome some of these practical limitations. In the new procedure, testing on the spontaneous recognition task occurs within an arena with a start/holding box attached to it to which the animal can return themselves at the end of a stage through a return door.…”

Section: Introductionmentioning

confidence: 99%

Cholinergic input to the hippocampus is not required for a model of episodic memory in the rat, even with multiple consecutive events

Seel

Eacott

Langston

et al. 2018

Behavioural Brain Research

Self Cite

View full text Add to dashboard Cite

Previous work has shown that depletion of the cholinergic input to the hippocampus produces no impairment in an episodic (what-where-which) memory task in rats. However, in contrast a where-which task was significantly impaired. Models of acetylcholine function related to pattern separation were used to explain this result. Recent development of spontaneous recognition tasks to assess multiple trials consecutively in the same testing session allow an opportunity to assess whether an increase in interference produces an impairment in the episodic memory task using the same cholinergic lesion. By increasing the number of trials happening consecutively the proactive interference between events being remembered increases, with the prediction that a reduction in pattern separation as a result of reduced acetylcholine in the hippocampus would now produce an impairment in this task. We show that a continual trials approach to the episodic memory task has no impact on the effects of cholinergic depletion of the hippocampus, with effects mirroring those from using just one trial a day approaches to these tasks. We suggest that pattern separation models of acetylcholine function can still explain our findings, but with an apparent emphasis on context-specific locations rather than all types of memory.

show abstract

Moving beyond standard procedures to assess spontaneous recognition memory

Cited by 51 publications

References 151 publications

Deleting both PHLPP1 and CANP1 rescues impairments in long-term potentiation and learning in both single knockout mice

Deleting both PHLPP1 and CANP1 rescues impairments in long-term potentiation and learning in both single knockout mice

Scopolamine Induces Deficits in Spontaneous Object-Location Recognition and Fear-Learning in Marmoset Monkeys

Cholinergic input to the hippocampus is not required for a model of episodic memory in the rat, even with multiple consecutive events

Contact Info

Product

Resources

About