Dopamine D2 receptors in WFS1-neurons regulate food-seeking and avoidance behaviors.

The selection and optimization of appropriate adaptive responses depends on interoceptive and exteroceptive stimuli as well as on the animal's ability to switch from one behavioral strategy to another. Although growing evidence indicate that dopamine D2R-mediated signaling events ensure the selection of the appropriate strategy for each specific situation, the underlying neural circuits through which they mediate these effects are poorly characterized. Here, we investigated the role of D2R signaling in a mesolimbic neuronal subpopulation expressing the Wolfram syndrome 1 (Wfs1) gene.

Psychostimulant Drugs Activate Cell-type Specific and Topographic cFos Expression in the Lumbar Spinal Cord.

Psychostimulant drugs, such as cocaine, d-amphetamine and methylphenidate, alter a wide range of behaviors including locomotor activity and somatosensory perception. These altered behaviors are accompanied by the activation of specific neuronal populations within reward-, emotion- and locomotion-related circuits. However, whether such regulation occurs at the level of the spinal cord, a key node for neural circuits integrating and coordinating sensory and motor functions has never been addressed.

Cerebellar dopamine D2 receptors regulate social behaviors.

The cerebellum, a primary brain structure involved in the control of sensorimotor tasks, also contributes to higher cognitive functions including reward, emotion and social interaction. Although the regulation of these behaviors has been largely ascribed to the monoaminergic system in limbic regions, the contribution of cerebellar dopamine signaling in the modulation of these functions remains largely unknown. By combining cell-type-specific transcriptomics, histological analyses, three-dimensional imaging and patch-clamp recordings, we demonstrate that cerebellar dopamine D2 receptors (D2Rs) in mice are preferentially expressed in Purkinje cells (PCs) and regulate synaptic efficacy onto PCs.

Outcome of caudal superficial epigastric axial pattern flaps in dogs and cats: 70 cases (2007-2020).

Objectives: To describe the outcome and complications associated with the use of caudal superficial epigastric axial pattern flaps in dogs and cats.

Material And Methods: Multicentre retrospective review and descriptive study of clinical records of dogs and cats having undergone caudal superficial epigastric axial pattern flaps between 2007 and 2020. Data retrieved included signalment, aetiology of surgical defect, tumour type, presence/absence of clean surgical margins, presence/absence of post-operative wound infection, use of peri- and post-operative antibiotics, duration of anaesthesia, duration of surgery, presence and duration of hypothermia, presence and duration of hypotension, presence/absence of post-operative surgical drain and length of caudal superficial epigastric axial pattern flap.

Regulation of GluA1 phosphorylation by d-amphetamine and methylphenidate in the cerebellum.

Prescription stimulants, such as d-amphetamine or methylphenidate are used to treat suffering from attention-deficit hyperactivity disorder (ADHD). They potently release dopamine (DA) and norepinephrine (NE) and cause phosphorylation of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit GluA1 in the striatum. Whether other brain regions are also affected remains elusive.

Cartography of hevin-expressing cells in the adult brain reveals prominent expression in astrocytes and parvalbumin neurons.

Hevin, also known as SPARC-like 1, is a member of the secreted protein acidic and rich in cysteine family of matricellular proteins, which has been implicated in neuronal migration and synaptogenesis during development. Unlike previously characterized matricellular proteins, hevin remains strongly expressed in the adult brain in both astrocytes and neurons, but its precise pattern of expression is unknown. The present study provides the first systematic description of hevin mRNA distribution in the adult mouse brain.

Ribosomal Protein S6 Phosphorylation Is Involved in Novelty-Induced Locomotion, Synaptic Plasticity and mRNA Translation.

The phosphorylation of the ribosomal protein S6 (rpS6) is widely used to track neuronal activity. Although it is generally assumed that rpS6 phosphorylation has a stimulatory effect on global protein synthesis in neurons, its exact biological function remains unknown. By using a phospho-deficient rpS6 knockin mouse model, we directly tested the role of phospho-rpS6 in mRNA translation, plasticity and behavior.

Repeated Exposure to D-Amphetamine Decreases Global Protein Synthesis and Regulates the Translation of a Subset of mRNAs in the Striatum.

Repeated psychostimulant exposure induces persistent gene expression modifications that contribute to enduring changes in striatal GABAergic spiny projecting neurons (SPNs). However, it remains unclear whether changes in the control of mRNA translation are required for the establishment of these durable modifications. Here we report that repeated exposure to D-amphetamine decreases global striatal mRNA translation.

Anatomical and molecular characterization of dopamine D1 receptor-expressing neurons of the mouse CA1 dorsal hippocampus.

In the hippocampus, a functional role of dopamine D1 receptors (D1R) in synaptic plasticity and memory processes has been suggested by electrophysiological and pharmacological studies. However, comprehension of their function remains elusive due to the lack of knowledge on the precise localization of D1R expression among the diversity of interneuron populations. Using BAC transgenic mice expressing enhanced green fluorescent protein under the control of D1R promoter, we examined the molecular identity of D1R-containing neurons within the CA1 subfield of the dorsal hippocampus.

Peripheral and central CB1 cannabinoid receptors control stress-induced impairment of memory consolidation.

Stressful events can generate emotional memories linked to the traumatic incident, but they also can impair the formation of nonemotional memories. Although the impact of stress on emotional memories is well studied, much less is known about the influence of the emotional state on the formation of nonemotional memories. We used the novel object-recognition task as a model of nonemotional memory in mice to investigate the underlying mechanism of the deleterious effect of stress on memory consolidation.

Microglial activation underlies cerebellar deficits produced by repeated cannabis exposure.

Chronic cannabis exposure can lead to cerebellar dysfunction in humans, but the neurobiological mechanisms involved remain incompletely understood. Here, we found that in mice, subchronic administration of the psychoactive component of cannabis, delta9-tetrahydrocannabinol (THC), activated cerebellar microglia and increased the expression of neuroinflammatory markers, including IL-1β. This neuroinflammatory phenotype correlated with deficits in cerebellar conditioned learning and fine motor coordination.

Operant behavior to obtain palatable food modifies neuronal plasticity in the brain reward circuit.

Palatability enhances food intake by hedonic mechanisms that prevail over caloric necessities. Different studies have demonstrated the role of endogenous cannabinoids in the mesocorticolimbic system in controlling food hedonic value and consumption. We hypothesize that the endogenous cannabinoid system could also be involved in the development of food-induced behavioral alterations, such as food-seeking and binge-eating, by a mechanism that requires neuroplastic changes in the brain reward pathway.

Operant behavior to obtain palatable food modifies ERK activity in the brain reward circuit.

Food palatability produces behavioral modifications that resemble those induced by drugs of abuse. Palatability-induced behavioral changes require both, the activation of the endogenous cannabinoid system, and changes in structural plasticity in neurons of the brain reward pathway. The ERK intracellular pathway is activated by CB1 receptors (CB1-R) and plays a crucial role in neuroplasticity.