Mechanisms of Synaptic Plasticity and Recognition Memory in the Perirhinal Cortex

Valproic Acid Modifies Synaptic Structure and Accelerates Neurite Outgrowth Via the Glycogen Synthase Kinase‐3β Signaling Pathway in an Alzheimer's Disease Model

“…GSK‐3β also regulates CREB, which modulates plasticity and memory . CREB activation is regulated by phosphorylation at Ser133, which controls the induction of many genes, including BDNF .…”

Noradrenergic activation of the basolateral amygdala modulates the consolidation of object-in-context recognition memory

“…Furthermore, β-adrenoceptor blockade with propranolol during memory encoding was shown to diminish the enhancement of hippocampal activity for emotional items at retention testing, when propranolol was no longer active (Strange and Dolan, 2004). Several studies have indicated that object-in-context memory also relies heavily on the hippocampus (Mumby et al, 2002; Balderas et al, 2008), whereas recognition of a novel object itself requires neuronal plasticity in perirhinal and insular cortical regions (Ennaceur and Aggleton, 1997; Bermudez-Rattoni et al, 2005; Albasser et al, 2009; Roozendaal et al, 2010; Banks et al, 2014; Bermudez-Rattoni, 2014). Thus, in further agreement with the memory modulation theory, the present findings clearly suggest that the post-training manipulation of noradrenergic activity within the BLA likely altered memory for this task by changing plasticity in other brain regions and firmly establish that this memory was formed and expressed in the absence of explicit training or motivation, reflecting a naturally formed memory devoid of high levels of arousal.…”

“…These findings thus indicate that noradrenergic activation of the BLA is also able to modulate the consolidation of non-aversive or non-fearful memories and provide evidence that this neuromodulatory system ensures lasting memories of significant experiences with varying degrees of emotionality. Standard object recognition training and memory for an object itself has been shown to depend primarily on cortical areas (Ennaceur and Aggleton, 1997; Bermudez-Rattoni et al, 2005; Albasser et al, 2009; Roozendaal et al, 2010; Banks et al, 2014; Bermudez-Rattoni, 2014). However, recognition memory as an integrated whole is more complex and encompasses a number of additional components, such as an item's associations with its context, place, etc., and involves a network of interacting brain regions (Bussey et al, 1999, 2000; Wan et al, 1999).…”

GABAergic inhibition gates excitatory LTP in perirhinal cortex

“…A role for e‐LTD during learning is supported by the observations that PRh neurons can become less responsive to familiar visual stimuli (von Linstow Roloff et al, ; Zhu, Brown, & Aggleton, ). Although distinct cellular mechanisms have been identified for the induction of e‐LTP and e‐LTD (Banks, Warburton, Brown, & Bashir, ), we sought to determine whether synaptic inhibition could serve as a gate between these two forms of excitatory synaptic plasticity. Our results suggest that strong synaptic inhibition biased plasticity toward e‐LTD, whereas reduced inhibition permitted the induction of e‐LTP (Figure ).…”