Topic: aversive stimuli

The dopaminergic system facilitates associative learning and motivation by signaling reward expectation and positive or negative valence in selected brain regions. Previous studies measuring somatic and axonal activity suggest a heterogeneous representation of reinforcement signaling by dopaminergic neurons, but it remains unclear how dopamine signals for expectation and valence interact in various brain regions. Here, we used an improved fluorescent dopamine sensor to record dopamine signals associated with reward predictions and valence in eight distinct striatal and non-striatal regions. We

Individual’s survival relies on choosing optimal coping behaviors facing threats. The lateral habenula (LHb) is a pivotal structure when facing aversive stimuli as well as environmental cues predicting them. While it’s clear that individual LHb neurons together with LHb circuits are engaged in those process, how non-neural cells respond in similar scenarios remains an open question. Hence, we propose to study the involvement of LHb astrocytes during the encoding of aversive stimuli. Using in vivo expression of the genetically encoded calcium biosensor Gcamp8s and photometry-based recordings, w

Aims: The identification of peripheral biomarkers of brain dysfunctions is essential to aid diagnosis and facilitate patient stratification. MicroRNAs are excellent candidate molecules to this purpose, as they can be expressed in the brain with regional and functional specificity, and they are highly stable in blood serum, unlike other RNA transcripts. Mir-34a is expressed with high specificity in a subpopulation of GABAergic neurons within the mouse Dorsal Raphe Nuclei (DRN), where it regulates GABAergic transmission in response to aversive stimuli. However, a direct connection between the br

REM sleep has been hypothesized to promote emotional resilience, but no neuronal circuitsmediating this have been identified. We find that in mice, somatostatin (Som) neurons in theentopeduncular nucleus (EPSom)/internal globus pallidus are predominantly active during REMsleep. This unique REM activity is necessary and sufficient for maintaining normal REM sleep.Inhibiting or exciting EPSom neurons reduced or increased REM sleep duration, respectively.Activation of the sole downstream target of EPSom neurons, Vglut2 cells in the lateral habenula(LHb), increased sleep via the ventral tegmental