Publications by authors named "Barrot M"

Depression is associated with dysregulated circadian rhythms, but the role of intrinsic clocks in mood-controlling brain regions remains poorly understood. We found increased circadian negative loop and decreased positive clock regulators expression in the medial prefrontal cortex (mPFC) of a mouse model of depression, and a subsequent clock countermodulation by the rapid antidepressant ketamine. Selective Bmal1KO in CaMK2a excitatory neurons revealed that the functional mPFC clock is an essential factor for the development of a depression-like phenotype and ketamine effects.

View Article and Find Full Text PDF
Article Synopsis
  • - Researchers studied the connection between chronic pain and depression in mice, finding that a specific neuronal pathway linking the basolateral amygdala and anterior cingulate cortex is crucial for developing depression related to chronic pain.
  • - Activation of this pathway in healthy mice not experiencing pain can still induce depressive-like behaviors and disrupt gene activity similar to what's seen in human depression, particularly affecting myelination-related genes.
  • - The study highlights the importance of the amygdalo-cingulate pathway in the link between pain and depression, identifying Sema4a as a key factor in emotional issues and signaling irregular myelination processes that affect mood stability.
View Article and Find Full Text PDF

The voltage-gated sodium channel Nav1.7 is encoded by gene and plays a critical role in pain sensitivity. Several gain-of-function (GOF) mutations have been found in patients with small fiber neuropathy (SFN) having chronic pain, including the R185H mutation.

View Article and Find Full Text PDF
Article Synopsis
  • Food intake is essential for survival but excessive consumption of fat and sugar can lead to obesity, a growing health concern.
  • The enjoyment derived from eating, especially from high-fat and high-sugar foods, activates pleasure centers in the brain, particularly the striatal complex and mesolimbic dopamine system.
  • This review explores how feeding affects various receptors and neurotransmitters in the brain, focusing on how these neurochemical systems influence the intake of palatable foods.
View Article and Find Full Text PDF
Article Synopsis
  • The study examines the role of the tail of the ventral tegmental area (tVTA) in processing reward prediction errors and how it responds to different stimuli, particularly focusing on food restriction and food-predicting cues.
  • Researchers found that while food-restricting rats didn't trigger the expected genetic response (c-Fos) in the tVTA, exposure to cues predicting food did stimulate this response, even without feeding.
  • The findings suggest that the tVTA primarily responds to reward cues rather than the aversive state of food restriction itself, highlighting its importance in understanding reward prediction mechanisms in the brain.
View Article and Find Full Text PDF

Neuropathic pain arises as a consequence of a lesion or disease affecting the somatosensory nervous system. It is accompanied by neuronal and non-neuronal alterations, including alterations in intracellular second messenger pathways. Cellular levels of 3',5'-cyclic adenosine monophosphate (cAMP) and 3',5'-cyclic guanosine monophosphate (cGMP) are regulated by phosphodiesterase (PDE) enzymes.

View Article and Find Full Text PDF

Background And Objective: Neuropathic pain arises as a direct consequence of a lesion or disease affecting the somatosensory system. A number of preclinical studies have provided evidence for the involvement of cytokines, predominantly secreted by a variety of immune cells and by glial cells from the nervous system, in neuropathic pain conditions. Clinical trials and the use of anti-cytokine drugs in different neuropathic aetiologies support the relevance of cytokines as treatment targets.

View Article and Find Full Text PDF

Central dopamine signaling regulates reward-related aspects of feeding behavior, and during diet-induced obesity dopamine receptor signaling is altered. Yet, the influence of dopamine signaling on the consumption of specific dietary components remains to be elucidated. We have previously shown that 6-hydroxydopamine-mediated lesions of dopamine neuron terminals in the lateral shell of the nucleus accumbens promotes fat intake in rats fed a multi-component free-choice high-fat high-sugar (fcHFHS) diet.

View Article and Find Full Text PDF

Dopamine influences food intake behavior. Reciprocally, food intake, especially of palatable dietary items, can modulate dopamine-related brain circuitries. Among these reciprocal impacts, it has been observed that an increased intake of dietary fat results in blunted dopamine signaling and, to compensate this lowered dopamine function, caloric intake may subsequently increase.

View Article and Find Full Text PDF

Tricyclic antidepressants that inhibit serotonin and noradrenaline reuptake, such as amitriptyline, are among the first-line treatments for neuropathic pain, which is caused by a lesion or disease affecting the somatosensory nervous system. These treatments are, however, partially efficient to alleviate neuropathic pain symptoms, and better treatments are still highly required. Interactions between neurons and glial cells participate in neuropathic pain processes, and importantly, connexins-transmembrane proteins involved in cell-cell communication-contribute to these interactions.

View Article and Find Full Text PDF

The adrenergic system, because of its reported implication in pain mechanisms, may be a potential target for chronic pain treatment. We previously demonstrated that β-adrenoceptors (β-ARs) are essential for neuropathic pain treatment by antidepressant drugs, and we showed that agonists of β-ARs, that is, β-mimetics, had an antiallodynic effect per se following chronic administration. To further explore the downstream mechanism of this action, we studied here the role of the opioid system.

View Article and Find Full Text PDF

Neuropathic pain is a challenging condition for which current therapies often remain unsatisfactory. Chronic administration of β2 adrenergic agonists, including formoterol currently used to treat asthma and chronic obstructive pulmonary disease, alleviates mechanical allodynia in the sciatic nerve cuff model of neuropathic pain. The limited clinical data currently available also suggest that formoterol would be a suitable candidate for drug repurposing.

View Article and Find Full Text PDF

Parkinson's disease is a neurodegenerative disorder partly caused by the loss of the dopamine neurons of the nigrostriatal pathway. It is accompanied by motor as well as non-motor symptoms, including pain and depression. The tail of the ventral tegmental area (tVTA) or rostromedial tegmental nucleus (RMTg) is a GABAergic mesopontine structure that acts as a major inhibitory brake for the substantia nigra pars compacta (SNc) dopamine cells, thus controlling their neuronal activity and related motor functions.

View Article and Find Full Text PDF
Article Synopsis
  • Mood disorders like depression and anxiety often occur in patients with chronic pain, leading researchers to create rodent models to study these relationships.
  • The review focuses on three main types of chronic pain—neuropathic, inflammatory, and fibromyalgia—and discusses the corresponding animal models used for research.
  • It emphasizes the need for more standardized results in studying pain-related mood disorders while summarizing recent advancements in behavioral testing methods to evaluate anxiety and depressive-like symptoms.
View Article and Find Full Text PDF

Neuropathic pain is a chronic pain caused by a lesion or disease affecting the somatosensory nervous system. To date, no specific treatment has been developed to cure this pain. Antidepressants and anticonvulsant drugs are used, but they do not demonstrate universal efficacy, and they often cause detrimental adverse effects.

View Article and Find Full Text PDF

Parkinson's disease is a neurodegenerative disease leading to the loss of midbrain dopamine neurons. It is well known and characterized by motor symptoms that are secondary to the loss of dopamine innervation, but it is also accompanied by a range of various non-motor symptoms, including pain and psychiatric disorders such as anxiety and depression. These non-motor symptoms usually appear at early stages of the disease, sometimes even before the first motor symptoms, and have a dramatic impact on the quality of life of the patients.

View Article and Find Full Text PDF

In addition to treating depression, antidepressant drugs are also a first-line treatment for neuropathic pain, which is pain secondary to lesion or pathology of the nervous system. Despite the widespread use of these drugs, the mechanism underlying their therapeutic action in this pain context remains partly elusive. The present study combined data collected in male and female mice from a model of neuropathic pain and data from the clinical setting to understand how antidepressant drugs act.

View Article and Find Full Text PDF

Peripheral delta opioid (DOP) receptors are essential for the antiallodynic effect of the tricyclic antidepressant nortriptyline. However, the population of DOP-expressing cells affected in neuropathic conditions or underlying the antiallodynic activity of antidepressants remains unknown. Using a mouse line in which DOP receptors were selectively ablated in cells expressing Nav1.

View Article and Find Full Text PDF

Pain associates both sensory and emotional aversive components, and often leads to anxiety and depression when it becomes chronic. Here, we characterized, in a mouse model, the long-term development of these sensory and aversive components as well as anxiodepressive-like consequences of neuropathic pain and determined their electrophysiological impact on the anterior cingulate cortex (ACC, cortical areas 24a/24b). We show that these symptoms of neuropathic pain evolve and recover in different time courses following nerve injury in male mice.

View Article and Find Full Text PDF

4-phenylpyridin-2-yl-guanidine (5b): a new inhibitor of the overproduction of pro-inflammatory cytokines (TNFα and Il1β) was identified from a high-throughput screening of a chemical library on human peripheral blood mononuclear cells (PBMCs) after LPS stimulation. Derivatives, homologues and rigid mimetics of 5b were designed and synthesized, and their cytotoxicity and ability to inhibit TNFα overproduction were evaluated. Among them, compound 5b and its mimetic 12 (2-aminodihydroquinazoline) showed similar inhibitory activities, and were evaluated in vivo in models of lung inflammation and neuropathic pain in mice.

View Article and Find Full Text PDF
Article Synopsis
  • Background: Surgeries leading to nerve injury can cause chronic pain; there’s increasing interest in preemptive treatments to prevent this pain.
  • Methods: In a study with male mice, researchers induced neuropathic pain and assessed the effectiveness of various drugs, comparing early treatment during surgery with treatment starting weeks later.
  • Results: Ketamine worked best right after surgery, and while early anticonvulsants weren't effective immediately, they helped prevent long-term pain; certain antidepressants also reduced pain when treatment began later.
View Article and Find Full Text PDF

The anterior cingulate cortex (ACC), constituted by areas 25, 32, 24a and 24b in rodents, plays a major role in cognition, emotion and pain. In a previous study, we described the afferents of areas 24a and 24b and those of areas 24a' and 24b' of midcingulate cortex (MCC) in mice and highlighted some density differences among cingulate inputs (Fillinger et al., Brain Struct Funct 222:1509-1532, 2017).

View Article and Find Full Text PDF

Background: Depression is frequently associated with chronic pain or chronic stress. Among cortical areas, the anterior cingulate cortex (ACC, areas 24a and 24b) appears to be important for mood disorders and constitutes a neuroanatomical substrate for investigating the underlying molecular mechanisms. The current work aimed at identifying ACC molecular factors subserving depression.

View Article and Find Full Text PDF