Optogenetic manipulations

Basal ganglia (BG) circuits are crucial for motor initiation and suppression. Dopamine loss in these circuits triggers Parkinson's disease (PD) and debilitating motor impairments such as akinesia and bradykinesia. Levodopa treatments alleviates PD symptoms, but often leads to abnormal involuntary movements known as levodopa-induced dyskinesias (LIDs). Understanding the neuronal mechanism of LIDs is essential for developing novel therapeutic strategies. Recent studies suggest that LIDs result from abnormal striatal activity, yet how this activity affects downstream BG circuits to generate LIDs

To behave optimally, animals build models of the world based on structural regularities to allow accurate prediction of the value of actions. Although powerful, the computational expense of updating these models limits their usefulness in ever-changing environments. Theoretical models have suggested that a way around these limitations is to separate the representation of structure from the associated value, allowing values to be rapidly updated when necessary. However, it is still unclear how this is implemented in the brain. To address this, we developed an odour-based task that requires mice

The COVID-19 pandemic impacted social life by forcing “social distancing”. This measure has not only severely disrupted daily social interactions but has also led to an increase in mental health problems. As a result, understanding the neurobiological mechanisms underlying pathogen threat-induced social avoidance (PTSA) has become increasingly important. Studies in rodents have proved valuable in the investigation of PTSA. Mice, for instance, innately avoid sick conspecifics, although little is known about the specific behavioral and circuit mechanisms underlying this response. We hypothesized

Hyperactivity is a persistent symptom of anorexia nervosa (AN) that often precedes occurrence of the disease, and constitutes a major barrier to recovery. Alteration of mesolimbic dopamine transmission has been hypothesized as a critical factor for the development and maintenance of AN and hyperactivity. However, the nature of dopamine dysfunction in AN, and the underlying mechanisms remain unclear. We therefore aimed at i) characterizing the impact of the activity-based anorexia (ABA) model on ventral tegmental area dopamine (VTADA) neurons and ii) determining whether restoring activity of VT

The termination of a meal is controlled by dedicated neural circuits in the caudal brainstem. A key challenge is to understand how these circuits transform the sensory signals generated during feeding into dynamic control of behaviour. The caudal nucleus of the solitary tract (cNTS) is the first site in the brain where many meal-related signals are sensed and integrated, but how the cNTS processes ingestive feedback during behaviour is unknown. Here we describe how prolactin-releasing hormone (PRLH) and GCG neurons, two principal cNTS cell types that promote non-aversive satiety, are regulated

In emotion research, anxiety and fear have always been interconnected, sharing overlapping brain structures and neural circuitry. Recent investigations, however, have unveiled parallel long-range projection pathways originating from the ventral hippocampus, shedding light on their distinct roles in anxiety and fear. Specifically, vCA1 projections to the lateral hypothalamus and medial prefrontal cortex are associated with anxiety-related experiences, whereas vCA1 projections to the amygdala mediate context-dependent fear. However, the precise mechanisms coordinating these parallel vCA1 project

…oscillatory phase estimation and apply optogenetic manipulations at precise phases of hippocampal theta during high-density electrophysiological recordings in head-fixed mice while they navigate a virtual environment. The precise timing of single-unit spiking relative to network-wide oscillations (i.e., phase locking) has long been thought to maintain excitatory-inhibitory homeostasis and coordinate cognitive processes, but due to intense experimental demands, the causal influence of this phenomenon has never b

Summary: Dopamine has long been known to critically contribute to learning. The canonical view is that midbrain dopamine neurons broadcast errors in reward prediction. These learning signals are thought to cache the general value of an outcome to its predictor and to reinforce response policies that rely on past success, rather than forethought of specific outcomes. But, to ensure flexible behavior, we do not just learn the general value of predictive events. We also encode the relationships between these cues and the identifying features of their associated outcomes. Such stimulus-outcome mem

Inferring the mappings between actions and sensory feedback is a fundamental aspect of brain function. These mappings are described by two types of internal models – one that transforms motor signals into predictions of sensory feedback (forward model), and one that transforms sensory goals onto the motor commands necessary to achieve those goals (inverse model). One promising theoretical framework that provides computational ground for learning and maintaining these mappings, is that of predictive processing. The functional implementation of this algorithm in cortex implies two computational

Coping with threatening situations requires both identifying stimuli predicting danger and selecting adaptive behavioral responses in order to survive. The dorso medial prefrontal cortex (dmPFC) is a critical structure involved in the regulation of threat-related behaviour, yet it is still largely unclear how threat-predicting stimuli and defensive behaviours are associated within prefrontal networks in order to successfully drive adaptive responses. Over the past years, we used a combination we used a combination of extracellular recordings, neuronal decoding approaches, and state of the art

…neuronal decoding approaches, and optogenetic manipulations to sho

…neuronal decoding approaches, and optogenetic manipulations to sho