scholarly journals Ex vivo dissection of optogenetically activated mPFC and hippocampal inputs to neurons in the basolateral amygdala: implications for fear and emotional memory

Author(s):  
Cora Hübner ◽  
Daniel Bosch ◽  
Andrea Gall ◽  
Andreas Lüthi ◽  
Ingrid Ehrlich
2021 ◽  
Author(s):  
Kay Tye ◽  
Gillian Matthews ◽  
Mackenzie Lemieux ◽  
Elizabeth Brewer ◽  
Raymundo Miranda ◽  
...  

Abstract Affiliative social connections facilitate well-being and survival in numerous species. Engaging in social interactions requires positive and negative motivational drive, elicited through coordinated activity across neural circuits. However, the identity, interconnectivity, and functional encoding of social information within these circuits remains poorly understood. Here, we focused on downstream projections of dorsal raphe nucleus (DRN) dopamine neurons (DRNDAT), which we previously implicated in ‘negative drive’-induced social motivation. We show that three prominent DRNDAT projections – to the bed nucleus of the stria terminalis (BNST), central amygdala (CeA), and posterior basolateral amygdala (BLP) – play separable roles in behavior, despite substantial collateralization. Photoactivation of the DRNDAT-CeA projection promoted social behavior and photoactivation of the DRNDAT-BNST projection promoted exploratory behavior, while the DRNDAT-BLP projection supported place avoidance, suggesting a negative affective state. Downstream regions showed diverse, region-specific, receptor expression, poising DRNDAT neurons to act through dopamine, neuropeptide, and glutamate transmission. Furthermore, we show ex vivo that the effect of DRNDAT photostimulation on downstream neuron excitability was predicted by baseline cell properties, suggesting cell-type-specific modulation. Collectively, these data indicate that DRNDAT neurons may bias behavior via precise modulation of cellular activity in broadly-distributed target structures.


Neuroscience ◽  
2012 ◽  
Vol 206 ◽  
pp. 7-16 ◽  
Author(s):  
A. Hetzel ◽  
G.E. Meredith ◽  
D.J. Rademacher ◽  
J.A. Rosenkranz

2019 ◽  
Author(s):  
Wataru Ito ◽  
Brendon Fusco ◽  
Alexei Morozov

AbstractNatural brain adaptations often involve changes in synaptic strength. The artificial manipulations can help investigate the role of synaptic strength in a specific brain circuit not only in various physiological phenomena like correlated neuronal firing and oscillations but also in behaviors. High and low-frequency stimulation at presynaptic sites has been used widely to induce long-term potentiation (LTP) and depression (LTD), respectively. This approach is effective in many brain areas, but not in the basolateral amygdala (BLA), because the robust local GABAergic tone inside the BLA restricts synaptic plasticity. Here, we identified the subclass of GABAergic neurons that gate LTP in the BLA afferents from the dorsomedial prefrontal cortex (dmPFC). Chemogenetic suppression of somatostatin-positive interneurons (Sst-INs) enabled the ex vivo LTP by high-frequency stimulation of the afferent, but the suppression of parvalbumin-positive interneurons (PV-INs) did not. Moreover, optogenetic suppression of Sst-INs with Arch also enabled LTP of the dmPFC-BLA synapses both ex vivo and in vivo. These findings reveal that Sst-INs but not PV-INs gate LTP in the dmPFC-BLA pathway and provide a method for artificial synaptic facilitation in BLA.


2021 ◽  
Author(s):  
Céline Nicolas ◽  
Anes Ju ◽  
Yifan Wu ◽  
Hazim Eldirdiri ◽  
Sebastien Delcasso ◽  
...  

Abstract The response of the insular cortex (IC) and amygdala to stimuli of positive and negative valence were found to be altered in patients with anxiety disorders. However, the coding properties of neurons controlling anxiety and valence remain unknown. Combining photometry recordings and chemogenetics in mice, we uncover the anxiogenic control of projection neurons in the anterior IC (aIC), independently of their projection target. Using viral tracing and ex vivo electrophysiology, we characterize the monosynaptic aIC to the basolateral amygdala (BLA) connection, and employed projection-specific optogenetics, to reveal anxiogenic properties of aIC-BLA neurons in anxiety-related behaviors. Finally, using photometry recordings, we identified that aIC-BLA neurons are active in anxiogenic spaces, and in response to aversive stimuli. Together, these findings show that negative valence, as well as anxiety-related information and behaviors, are encoded by aICBLA glutamatergic neurons, providing a starting point to understand how alterations of this pathway contribute to psychiatric disorders.


2021 ◽  
Author(s):  
Kasra Manoocheri ◽  
Adam G Carter

Connections from the basolateral amygdala (BLA) to medial prefrontal cortex (PFC) regulate memory and emotion and become disrupted in neuropsychiatric disorders. We hypothesized that the diverse roles attributed to interactions between the BLA and PFC reflect multiple circuits nested within a wider network. To assess these circuits, we first used anatomy to show that the rostral BLA (rBLA) and caudal BLA (cBLA) differentially project to prelimbic (PL) and infralimbic (IL) subregions of the PFC, respectively. We then combined in vivo silicon probe recordings and optogenetics to show that rBLA primarily engages PL, whereas cBLA mainly influences IL. Using ex vivo whole-cell recordings and optogenetics, we then assessed which neuronal subtypes are targeted, showing that rBLA preferentially drives layer 2 (L2) cortico-amygdalar (CA) neurons in PL, whereas cBLA drives layer 5 (L5) pyramidal tract (PT) cells in IL. Lastly, we used soma-tagged optogenetics to explore the local circuits linking superficial and deep layers of PL, showing how rBLA can also impact L5 PT cells. Together, our findings delineate how subregions of the BLA target distinct networks within the PFC to have different influence on prefrontal output.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Joyonna Carrie Gamble-George ◽  
Rita Baldi ◽  
Lindsay Halladay ◽  
Adrina Kocharian ◽  
Nolan Hartley ◽  
...  

Mood and anxiety disorders are the most prevalent psychiatric conditions and are exacerbated by stress. Recent studies have suggested cyclooxygenase-2 (COX-2) inhibition could represent a novel treatment approach or augmentation strategy for affective disorders including anxiety disorders and major depression. We show that traditional COX-2 inhibitors and a newly developed substrate-selective COX-2 inhibitor (SSCI) reduce a variety of stress-induced behavioral pathologies in mice. We found that these behavioral effects were associated with a dampening of neuronal excitability in the basolateral amygdala (BLA) ex vivo and in vivo, and were mediated by small-conductance calcium-activated potassium (SK) channel and CB1 cannabinoid receptor activation. Taken together, these data provide further support for the potential utility of SSCIs, as well as traditional COX-2 inhibitors, as novel treatment approaches for stress-related psychiatric disorders.


2021 ◽  
Author(s):  
Ting Xu ◽  
Xinqi Zhou ◽  
Guojuan Jiao ◽  
Yixu Zeng ◽  
Weihua Zhao ◽  
...  

Exaggerated arousal and dysregulated emotion-memory interactions are key pathological dysregulations that accompany the development of post-traumatic stress disorder (PTSD). Current treatments for PTSD are of moderate efficacy and preventing the dysregulations already during exposure to threatening events may attenuate the development of PTSD-symptomatology. The present proof-of-concept study examined the potential of a single dose of the angiotensin II type 1 receptor (AT1R) antagonist losartan (LT) to attenuate the mnemonic advantage of threatening stimuli and the underlying neural mechanism. In a preregistered double-blind, between-subject, placebo-controlled pharmaco-fMRI study we combined an emotional subsequent memory paradigm with LT (n=29) or placebo treatment (n=30) and a surprise memory test after 24h washout. LT generally improved memory performance and abolished emotional memory enhancement for negative yet not positive material while emotional experience during encoding remained intact. LT further suppressed the hippocampus activity during encoding of subsequently remembered negative stimuli and abolished the positive association between higher activity in this region and subsequent better memory for negative material observed under placebo. On the network level LT reduced coupling between the hippocampus and the basolateral amygdala during successful encoding of negative stimuli. Overall, our findings suggest that LT has the potential to selectively attenuate memory formation for negative yet not positive information by decreasing hippocampus activity and its functional coupling strength with the left amygdala. These findings suggest a promising potential of LT to prevent preferential encoding and remembering of negative events, a mechanism that could prevent the emotion-memory dysregulations underlying the development of PTSD-symptomatology.


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