scholarly journals Role of the thalamic nucleus reuniens in mediating interactions between the hippocampus and medial prefrontal cortex during spatial working memory

2015 ◽  
Vol 9 ◽  
Author(s):  
Amy L. Griffin
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Thalamic Nucleus ◽  
Spatial Working Memory ◽  
Nucleus Reuniens

scholarly journals Nucleus reuniens is required for encoding and retrieving precise, hippocampal-dependent contextual fear memories in rats

2018 ◽  
Author(s):  
Karthik R. Ramanathan ◽  
Reed L. Ressler ◽  
Jingji Jin ◽  
Stephen Maren
Keyword(s):  
Prefrontal Cortex ◽  
Spatial Memory ◽  
Fear Conditioning ◽  
Medial Prefrontal Cortex ◽  
Thalamic Nucleus ◽  
Nmda Receptor Antagonist ◽  
Pavlovian Fear Conditioning ◽  
Contextual Memory ◽  
Nucleus Reuniens ◽  
Contextual Fear

AbstractThe nucleus reuniens (RE) is a ventral midline thalamic nucleus that interconnects the medial prefrontal cortex (mPFC) and hippocampus (HPC). Considerable data indicate that HPC-mPFC circuits are involved in contextual and spatial memory; however, it is not clear whether the RE mediates the acquisition or retrieval of these memories. To examine this question, we inactivated the RE with muscimol before either the acquisition or retrieval of Pavlovian fear conditioning in rats; freezing served as the index of fear. We found that RE inactivation before conditioning impaired the acquisition of contextual freezing, whereas inactivation of the RE prior to retrieval testing increased the generalization of freezing to a novel context; inactivation of the RE did not affect either the acquisition or expression of auditory fear conditioning. Interestingly, contextual conditioning impairments were absent when retrieval testing was also conducted after RE inactivation. Contextual memories acquired under RE inactivation were hippocampal-independent, insofar as contextual freezing in rats conditioned under RE inactivation was insensitive to intra-hippocampal infusions of the NMDA receptor antagonist, D,L-amino-5-phosophonovaleric acid (APV). Together, these data reveal that the RE supports hippocampal-dependent encoding of precise contextual memories that allow discrimination of dangerous from safe contexts. When the RE is inactive, however, alternate neural systems acquire an impoverished contextual memory that is only expressed when the RE is offline.SIGNIFICANCE STATEMENTThe midline thalamic nucleus reuniens (RE) coordinates communication between the hippocampus and medial prefrontal cortex, brain areas critical for contextual and spatial memory. Here we show that temporary pharmacological inactivation of RE impairs the acquisition and precision of contextual fear memories after Pavlovian fear conditioning in rats. However, inactivating the RE prior to retrieval testing restored contextual memory in rats conditioned after RE inactivation. Critically, we show that imprecise contextual memories acquired under RE inactivation are learned independently of the hippocampus. These data reveal that the RE is required for hippocampal-dependent encoding of precise contextual memories to support the discrimination of safe and dangerous contexts.

scholarly journals Cerebellar Purkinje cell simple spike activity in awake mice represents phase differences between oscillations in medial prefrontal cortex and hippocampus

2017 ◽  
Author(s):  
Samuel S. McAfee ◽  
Yu Liu ◽  
Roy V. Sillitoe ◽  
Detlef H. Heck
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Spike Activity ◽  
Spatial Working Memory ◽  
Memory Task ◽  
Temporal Coordination ◽  
Frequency Bands ◽  
Simple Spike ◽  
Phase Differences

AbstractThe cerebellum has long been recognized for its role in tasks involving precise timing, particularly the temporal coordination of movements. Here we asked whether cerebellar might be involved in the temporal coordination of the phases of neuronal oscillations in the medial prefrontal cortex (mPFC) and dorsal hippocampus CA1 region (CA1). These two structures and the cerebellum are jointly involved in spatial working memory. The phases of oscillations in the mPFC and CA1 have been shown to reach a stable alignment (coherence) during the decision making process in a spatial working memory task. Here we report that PC simple spike activity in the cerebellar lobulus simplex in awake, head-fixed mice represents specific phase differences between oscillations in the mPFC and CA1. Most PCs represented phase differences in more than one the conventional frequency bands (delta, theta, beta and gamma). Between the 32 PCs analyzed here, phase differences in all frequency bands were represented. PCs representing phase differences in the theta and low gamma bands showed significant population preference for mPFC phase leading CA1 phase. These findings support the possibility of a cerebellar involvement in the temporal coordination of phase relationships between oscillations in the mPFC and CA1.

Tagging items in spatial working memory: A unit-recording study in the rat medial prefrontal cortex

2010 ◽  
Vol 209 (2) ◽  
pp. 267-273 ◽  
Author(s):  
Paul de Saint Blanquat ◽  
Vincent Hok ◽  
Alice Alvernhe ◽  
Etienne Save ◽  
Bruno Poucet
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Spatial Working Memory ◽  
Unit Recording

scholarly journals Blockade of IP3-mediated SK channel signaling in the rat medial prefrontal cortex improves spatial working memory

2008 ◽  
Vol 15 (3) ◽  
pp. 93-96 ◽  
Author(s):  
A. R. Brennan ◽  
B. Dolinsky ◽  
M.-A. T. Vu ◽  
M. Stanley ◽  
M. F. Yeckel ◽  
...  
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Spatial Working Memory ◽  
Sk Channel
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