Changes in protein kinase C (PKC) activity, isozyme translocation, and GAP-43 phosphorylation in the rat hippocampal formation after a single-trial contextual fear conditioning paradigm

Hippocampus ◽  
2002 ◽  
Vol 12 (4) ◽  
pp. 457-464 ◽  
Author(s):  
Elizabeth Young ◽  
Teresa Cesena ◽  
Karina F. Meiri ◽  
Nora I. Perrone-Bizzozero
2000 ◽  
Vol 20 (16) ◽  
pp. 5906-5914 ◽  
Author(s):  
Edwin J. Weeber ◽  
Coleen M. Atkins ◽  
Joel C. Selcher ◽  
Andrew W. Varga ◽  
Banafsheh Mirnikjoo ◽  
...  

2013 ◽  
Vol 6 (273) ◽  
pp. ec94-ec94 ◽  
Author(s):  
Nancy R. Gough

The cellular model of memory is a synaptic plasticity event called long-term potentiation (LTP). LTP can be divided into two phases: The early phase (E-LTP) lasts less than 2 hours and does not require new protein synthesis, and the late phase (L-LTP) can last many hours and requires new protein synthesis. Translation of mRNAs is regulated through various mechanisms, one of which is the binding of poly(A)-binding protein (PABP) to the poly(A) tail of the target mRNA. PAIP2A and PAIP2B (PAIP-interacting protein 2A and 2B) inhibit translation by interfering with PABP function. Khoutorsky et al. found that degradation of PAIP2A, which is the form that is abundant in the brain, linked synaptic activity to enhanced translation and contributed to learning and memory in mice. Hippocampal slices from Paip2a–/– mice showed L-LTP in response to a stimulus that only triggered E-LTP in slices from wild-type mice and showed impaired L-LTP in response to a stimulus that triggered L-LTP in slices from wild-type mice. Consistent with these electrophysiological studies, behavorial memory tests indicated that Paip2a–/– mice showed faster learning in spatial long-term memory tests in response to weak training but showed impaired learning in response to a long-term contextual fear conditioning test that used a strong training paradigm. Experiments with cultured neurons and hippocampal slices showed an activity-dependent decrease in the abundance of PAIP2A that could be prevented by pharmacological inhibition of the calcium-dependent proteases calpains. The calpain-dependent reduction in PAIP2A was also detected in mice subjected to the contextual fear conditioning paradigm, and infusion of calpain inhibitors impaired long-term contextual fear memory. Increased production of calcium-calmodulin kinase IIα (CaMKIIα) occurs in response to synaptic activity and is necessary for learning. The abundance of CaMKIIα in the hippocampus was increased in Paip2a–/– mice trained in a contextual fear conditioning paradigm compared with untrained mice or wild-type trained mice. This increase in CaMKIIα resulted from increased translation because CaMKIIα mRNA was shifted to heavy polysome fractions in the brains of Paip2a–/– trained mice and the association of PABP with this mRNA was greatest in the Paip2a–/– trained mice. Thus, activity-dependent degradation of a translation inhibitor contributes to the enhanced translation needed for learning and memory.A. Khoutorsky, A, Yanagiya, C. G. Gkogkas, M. R. Fabian, M. Prager-Khoutorsky, R. Cao, K. Gamache, F. Bouthiette, A. Parsyan, R. E. Sorge, J. S. Mogil, K. Nader, J.-C. Lacaille, N. Sonenberg, Control of synaptic plasticity and memory via suppression of poly(A)-binding protein. Neuron78, 298–311 (2013). [Online Journal]


2009 ◽  
Vol 123 (5) ◽  
pp. 1148-1152 ◽  
Author(s):  
M. A. Burman ◽  
N. J. Murawski ◽  
F. L. Schiffino ◽  
J. B. Rosen ◽  
M. E. Stanton

2016 ◽  
Author(s):  
Justin W. Kenney ◽  
Ian C. Scott ◽  
Sheena A. Josselyn ◽  
Paul W. Frankland

AbstractZebrafish are a genetically tractable vertebrate that hold considerable promise for elucidating the molecular basis of behavior. Although numerous recent advances have been made in the ability to precisely manipulate the zebrafish genome, much less is known about many aspects learning and memory in adult fish. Here, we develop a contextual fear conditioning paradigm using an electric shock as the aversive stimulus. We find that contextual fear conditioning is modulated by shock intensity, prevented by inhibition of (N-methyl-D-aspartate) NMDA receptors, lasts at least 14 days, and exhibits extinction. Furthermore, fish of various background strains (AB, Tu, and TL) are able to acquire fear conditioning, but differ in fear extinction rates. Taken together, we find that contextual fear conditioning in zebrafish shares many similarities with the widely used contextual fear conditioning paradigm in rodents. Combined with the amenability of genetic manipulation in zebrafish, we anticipate that our paradigm will prove to be a useful complementary system in which to examine the molecular basis of vertebrate learning and memory.


2016 ◽  
Author(s):  
Nathen J. Murawski ◽  
Arun Asok

AbstractThe precise contribution of visual information to contextual fear-learning and discrimination has remained elusive. To better understand this contribution, we coupled the context pre-exposure facilitation effect (CPFE) fear conditioning paradigm with presentations of distinct visual scenes displayed on 4 LCD screens surrounding a conditioning chamber. Adult male Long-Evans rats received non-reinforced context pre-exposure on Day 1, an immediate 1.5 mA foot shock on Day 2, and a non-reinforced context test on Day 3. Rats were pre-exposed to either digital Context (dCtx) A, dCtx B, a distinct Context C, or no context on Day 1. Context A and B were identical except for the visual image displayed on the LCD monitors. Immediate shock and retention testing occurred in dCtx A. Rats pre-exposed dCtx A showed the CPFE with significantly higher levels of freezing compared to learning controls. Rats pre-exposed to Context B failed to show the CPFE, with freezing that did not differ significantly from any group. The results suggest that 1) visual information contributes to contextual fear learning in rats and that 2) visual components of the context can be parametrically controlled via LCD screens. Our approach offers a simple modification to contextual fear conditioning whereby the visual features of a context can be precisely controlled to better understand how rodents discriminate and generalize fear across environments.


2017 ◽  
Vol 171 ◽  
pp. 175-180 ◽  
Author(s):  
Ana Paula A. Bueno ◽  
Joselisa Péres Queiroz de Paiva ◽  
Moisés dos Santos Corrêa ◽  
Paula Ayako Tiba ◽  
Raquel Vecchio Fornari

Sign in / Sign up

Export Citation Format

Share Document