Dual medial prefrontal cortex and hippocampus projecting neurons in the paraventricular nucleus of the thalamus

2021 ◽  
Author(s):  
Tatiana D. Viena ◽  
Gabriela E. Rasch ◽  
Timothy A. Allen

AbstractThe paraventricular nucleus (PVT) of the midline thalamus is a critical higher-order cortico-thalamo-cortical integration site that plays a critical role in various behaviors including reward seeking, cue saliency, and emotional memory. Anatomical studies have shown that PVT projects to both medial prefrontal cortex (mPFC) and hippocampus (HC). However, dual mPFC-HC projecting neurons which could serve a role in synchronizing mPFC and HC activity during PVT-dependent behaviors, have not been explored. Here we used a dual retrograde adenoassociated virus (AAV) tracing approach to characterize the location and proportion of different projection populations that send collaterals to mPFC and/or ventral hippocampus (vHC). Additionally, we examined the distribution of calcium binding proteins calretinin (CR) and calbindin (CB) with respect to these projection populations PVT. We found that PVT contains separate populations of cells that project to mPFC, vHC, and those that innervate both regions. Interestingly, dual mPFC-HC projecting cells expressed neither CR or CB. Topographically, mPFC- and vHC-projecting CB+ and CR+ cells clustered around dual projecting neurons in PVT. These results are consistent with the features of dual mPFC-vHC projecting cells in the nucleus reuniens (RE) and suggestive of a functional mPFC-PVT-vHC system that may support mPFC-vHC interactions in PVT-dependent behaviors.

2007 ◽  
Vol 71 (6) ◽  
pp. 601-609 ◽  
Author(s):  
Robert P. Vertes ◽  
Walter B. Hoover ◽  
Klara Szigeti-Buck ◽  
Csaba Leranth

2021 ◽  
Vol 44 (1) ◽  
Author(s):  
Masaki Isoda

As a frontal node in the primate social brain, the medial prefrontal cortex (MPFC) plays a critical role in coordinating one's own behavior with respect to that of others. Current literature demonstrates that single neurons in the MPFC encode behavior-related variables such as intentions, actions, and rewards, specifically for self and other, and that the MPFC comes into play when reflecting upon oneself and others. The social moderator account of MPFC function can explain maladaptive social cognition in people with autism spectrum disorder, which tips the balance in favor of self-centered perspectives rather than taking into consideration the perspective of others. Several strands of evidence suggest a hypothesis that the MPFC represents different other mental models, depending on the context at hand, to better predict others’ emotions and behaviors. This hypothesis also accounts for aberrant MPFC activity in autistic individuals while they are mentalizing others. Expected final online publication date for the Annual Review of Neuroscience, Volume 44 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2018 ◽  
Author(s):  
Karthik R. Ramanathan ◽  
Reed L. Ressler ◽  
Jingji Jin ◽  
Stephen Maren

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.


2020 ◽  
Vol 30 (6) ◽  
pp. 3608-3616 ◽  
Author(s):  
Leonore Bovy ◽  
Ruud M W J Berkers ◽  
Julia C M Pottkämper ◽  
Rathiga Varatheeswaran ◽  
Guillén Fernández ◽  
...  

Abstract Mood-congruent memory bias is a critical characteristic of depression, but the underlying neural mechanism is largely unknown. Negative memory schemas might enhance encoding and consolidation of negative experiences, thereby contributing to the genesis and perpetuation of depressive pathology. To investigate this relationship, we aimed to perturb medial prefrontal cortex (mPFC) processing, using neuronavigated transcranial magnetic stimulation (TMS) targeting the mPFC. Forty healthy volunteers first underwent a negative mood induction to activate negative schema processing after which they received either active inhibitory (N = 20) or control (N = 20) stimulation to the mPFC. Then, all participants performed the encoding of an emotional false memory task. Recall and recognition performance was tested the following morning. Polysomnographic data were recorded continuously during the night before and after encoding. We observed a significantly lower false recognition of negative critical lures following mPFC inhibition, but no differences in veridical memory. These findings were supported by reaction time data, showing a relative slower response to negative compared with positive critical lures. The current findings support previous causal evidence for a role of the mPFC in schema memory processing and further suggest a role of the mPFC in memory bias.


2020 ◽  
Author(s):  
Lailun Nahar ◽  
Caleb A. Grant ◽  
Cameron Hewett ◽  
Diego Cortes ◽  
Ashlie N. Reker ◽  
...  

2005 ◽  
Vol 17 (5) ◽  
pp. 832-846 ◽  
Author(s):  
David M. Schnyer ◽  
Lindsay Nicholls ◽  
Mieke Verfaellie

Making judgments about the retrievability of information is a critical part of the metamemory processes engaged during remembering. A recent study of patients with frontal lesions suggests that ventral medial prefrontal cortex (VMPC) plays a critical role in such judgments [Schnyer, D. M., Verfaellie, M., Alexander, M. P., Lafleche, G., Nicholls, L., & Kaszniak, A. W. A role for right medial prefrontal cortex in accurate feeling of knowing judgments: Evidence from patients with lesions to frontal cortex. Neuropsychologia, 42, 957–966, 2004]. The observed impairment was thought to reflect an inability to determine the accessibility of memory contents. To further examine the neuroanatomical basis of content accessibility assessment, we used fMRI in an episodic feeling-of-knowing (FOK) paradigm. Participants were asked to make trial-by-trial predictions about the retrievability of the final word that completed studied sentences and then to select the correct completion from among alternatives. Results indicated that the VMPC is engaged during accurate FOK judgments and its activation is modulated by retrieval rating. Structural equations modeling supported the notion that VMPC, as part of a broader left hemisphere network involved in memory retrieval, monitors the output of the retrieval process. More generally, VMPC may participate in metacognitive processes that allow for the comparison of available data against an internal model.


2020 ◽  
Author(s):  
Nicholas Yeh ◽  
Jessica D. Payne ◽  
Sara Y. Kim ◽  
Elizabeth A. Kensinger ◽  
Joshua D. Koen ◽  
...  

AbstractPrevious research points to an association between retrieval-related activity in the medial prefrontal cortex (mPFC) and preservation of emotional information compared to co-occurring neutral information following sleep. Although the role of the mPFC in emotional memory likely begins at encoding, little research has examined how mPFC activity during encoding interacts with consolidation processes to enhance emotional memory. This issue was addressed in the present study using transcranial magnetic stimulation in conjunction with an emotional memory paradigm. Healthy males and females encoded negative and neutral scenes while undergoing concurrent TMS with an intermittent theta burst stimulation (iTBS) protocol. Participants received stimulation to either the mPFC or an active control site (motor cortex) during the encoding phase. Recognition memory for scene components (objects and backgrounds) was assessed after a short (30 minutes) and a long delay (24-hours including a night of sleep) to obtain measures of specific and gist-based memory processes. The results demonstrated that, relative to control stimulation, iTBS to the mPFC enhanced gist, but not specific, memory for negative objects on the long delay test. mPFC stimulation had no discernable effect on gist memory for objects on the short delay test nor on the background images at either test. These results suggest that mPFC activity occurring during encoding interacts with consolidation processes to selectively preserve the gist of negatively salient information.Significance StatementUnderstanding how emotional information is remembered over long delays is critical to understanding memory in the real world. The present study uses transcranial magnetic stimulation (TMS) to investigate the interplay between mPFC activity that occurs during memory encoding and its subsequent interactions with post-encoding consolidation processes. Excitatory TMS delivered to the mPFC during encoding enhanced gist-based memory for negatively valenced pictures on a test following a 24-hr delay, with no such effect on a test occurring shortly after the encoding phase. These results are consistent with the hypothesis that emotional aspects of memories are differentially subjected to consolidation processes, and that the mPFC might contribute to this “tag-and-capture” mechanism during the initial formation of such memories.


2021 ◽  
Vol 15 ◽  
Author(s):  
Sara Mejía-Chávez ◽  
Arturo Venebra-Muñoz ◽  
Fabio García-García ◽  
Aleph Alejandro Corona-Morales ◽  
Arturo Enrique Orozco-Vargas

Maternal separation has been shown to disrupt proper brain development and maturation, having profound consequences on the neuroendocrine systems in charge of the stress response, and has been shown to induce behavioral and cognitive abnormalities. At the behavioral level, maternal separation has been shown to increase offensive play-fighting in juvenile individuals and reduce social interest in adulthood. Since most of the studies that have evaluated the consequences of maternal separation on social behavior have focused on behavioral analysis, there is a need for a further understanding of the neuronal mechanisms underlying the changes in social behavior induced by maternal separation. Therefore, the aim of the present research was to assess the long-term effects of maternal separation on social interaction behavior and to assess the activity of several brain regions involved in the processing of social cues and reward upon social novelty exposure, using c-Fos immunohistochemistry as a marker of neuronal activity. Male Wistar rats were subjected to 4 h maternal separation during the neonatal period, 9:00 h–13:00 h from postnatal day 1 to 21, and exposed to social novelty during adulthood. After social novelty exposure, brains were fixed and coronal sections of the medial amygdala, lateral septum (LS), paraventricular nucleus of the hypothalamus, nucleus accumbens, and medial prefrontal cortex were obtained for c-Fos immunohistochemistry. Maternally separated rats spent less time investigating the novel peer, suggesting that maternal separation reduces social approach motivation. Furthermore, maternal separation reduced the number of c-Fos positive cells of the medial amygdala, paraventricular nucleus of the hypothalamus, LS, nucleus accumbens, and medial prefrontal cortex upon social novelty exposure. These findings suggest that maternal separation can reduce the plastic capacity of several brain nuclei, which constitute a physiological basis for the emergence of behavioral disorders presented later in life reported to be linked to early life adversity.


Sign in / Sign up

Export Citation Format

Share Document