Search results for "camp"
showing 10 items of 1995 documents
Extended Flight Bouts Require Disinhibition from GABAergic Mushroom Body Neurons
2019
Summary Insect flight is a complex behavior that requires the integration of multiple sensory inputs with flight motor output. Although previous genetic studies identified central brain monoaminergic neurons that modulate Drosophila flight, neuro-modulatory circuits underlying sustained flight bouts remain unexplored. Certain classes of dopaminergic and octopaminergic neurons that project to the mushroom body, a higher integrating center in the insect brain, are known to modify neuronal output based on contextual cues and thereby organismal behavior. This study focuses on how monoaminergic modulation of mushroom body GABAergic output neurons (MBONs) regulates the duration of flight bouts. O…
Differential Impact of Ad Libitum or Intermittent High-Fat Diets on Bingeing Ethanol-Mediated Behaviors
2019
Background: Dietary factors have significant effects on the brain, modulating mood, anxiety, motivation and cognition. To date, no attention has been paid to the consequences that the combination of ethanol (EtOH) and a high-fat diet (HFD) have on learning and mood disorders during adolescence. The aim of the present work was to evaluate the biochemical and behavioral consequences of ethanol binge drinking and an HFD consumption in adolescent mice. Methods: Animals received either a standard diet or an HFD (ad libitum vs. binge pattern) in combination with ethanol binge drinking and were evaluated in anxiety and memory. The metabolic profile and gene expression of leptin receptors and clock…
Hyperammonemia alters the mismatch negativity in the auditory evoked potential by altering functional connectivity and neurotransmission
2020
Minimal hepatic encephalopathy (MHE) is a neuropsychiatric syndrome produced by central nervous system dysfunction subsequent to liver disease. Hyperammonemia and inflammation act synergistically to alter neurotransmission, leading to the cognitive and motor alterations in MHE, which are reproduced in rat models of chronic hyperammonemia. Patients with MHE show altered functional connectivity in different neural networks and a reduced response in the cognitive potential mismatch negativity (MMN), which correlates with attention deficits. The mechanisms by which MMN is altered in MHE remain unknown. The objectives of this work are as follows: To assess if rats with chronic hyperammonemia rep…
Anxiolytic effects of muscarinic acetylcholine receptors agonist oxotremorine in chronically stressed rats and related changes in BDNF and FGF2 level…
2017
Rationale: In depressive disorders, one of the mechanisms proposed for antidepressant drugs is the enhancement of synaptic plasticity in the hippocampus and cerebral cortex. Previously, we showed that the muscarinic acetylcholine receptor (mAChR) agonist oxotremorine (Oxo) increases neuronal plasticity in hippocampal neurons via FGFR1 transactivation. Objectives: Here, we aimed to explore (a) whether Oxo exerts anxiolytic effect in the rat model of anxiety-depression-like behavior induced by chronic restraint stress (CRS), and (b) if the anxiolytic effect of Oxo is associated with the modulation of neurotrophic factors, brain-derived neurotrophic factor (BDNF) and fibroblast growth factor-2…
Hemisphere-dependent endocannabinoid system activity in prefrontal cortex and hippocampus of the Flinders Sensitive Line rodent model of depression
2019
Altered endocannabinoid (eCB) signaling is suggested as an important contributor to the pathophysiology of depression. To further elucidate this, we conducted a study using a genetic rat model of depression, the Flinders Sensitive Line (FSL), and their controls, the Flinders Resistant Line (FRL) rats. Plasma, right and left prefrontal cortex, and hippocampus were isolated from FSL and FRL rats. We analyzed each region for the eCB anandamide (AEA) and 2-arachidonoylglycerol (2-AG) levels by liquid chromatography/multiple reaction monitoring (LC/MRM), mRNA and protein levels of the cannabinoid type 1 receptor (CB1R), fatty acid amide hydrolase (FAAH) and monoacyl glycerol lipase (MAGL) by rea…
Multimodal determinants of phase-locked dynamics across deep-superficial hippocampal sublayers during theta oscillations
2020
Theta oscillations play a major role in temporarily defining the hippocampal rate code by translating behavioral sequences into neuronal representations. However, mechanisms constraining phase timing and cell-type-specific phase preference are unknown. Here, we employ computational models tuned with evolutionary algorithms to evaluate phase preference of individual CA1 pyramidal cells recorded in mice and rats not engaged in any particular memory task. We applied unbiased and hypothesis-free approaches to identify effects of intrinsic and synaptic factors, as well as cell morphology, in determining phase preference. We found that perisomatic inhibition delivered by complementary populations…
2018
In mammalian species, including humans, the hippocampal dentate gyrus (DG) is a primary region of adult neurogenesis. Aberrant adult hippocampal neurogenesis is associated with neurological pathologies. Understanding the cellular mechanisms controlling adult hippocampal neurogenesis is expected to open new therapeutic strategies for mental disorders. Microglia is intimately associated with neural progenitor cells in the hippocampal DG and has been implicated, under varying experimental conditions, in the control of the proliferation, differentiation and survival of neural precursor cells. But the underlying mechanisms remain poorly defined. Using fluorescent in situ hybridization we show th…
Discovery and characterization of two novel CB1 receptor splice variants with modified N-termini in mouse
2017
Numerous studies have been carried out in the mouse model, investigating the role of the CB1 cannabinoid receptor. However, mouse CB1 (mCB1) receptor differs from human CB1 (hCB1) receptor in 13 amino acid residues. Two splice variants, hCB1a and hCB1b, diverging in their amino-termini, have been reported to be unique for hCB1 and, via different signaling properties, contribute to CB1 receptor physiology and pathophysiology. We hypothesized that splice variants also exist for the mCB1 receptor and have different signaling properties. On murine hippocampal cDNA, we identified two novel mCB1 receptor splice variants generated by splicing of introns with 117 bp and 186 bp in the N-terminal dom…
2018
Summary Directed transport of transmembrane proteins is generally believed to occur via intracellular transport vesicles. However, using single-particle tracking in rat hippocampal neurons with a pH-sensitive quantum dot probe that specifically reports surface movement of receptors, we have identified a subpopulation of neuronal EphB2 receptors that exhibit directed motion between synapses within the plasma membrane itself. This receptor movement occurs independently of the cytoskeleton but is dependent on cholesterol and is regulated by neuronal activity.
2016
During hippocampal sharp wave/ripple (SWR) events, previously occurring, sensory input-driven neuronal firing patterns are replayed. Such replay is thought to be important for plasticity-related processes and consolidation of memory traces. It has previously been shown that the electrical stimulation-induced disruption of SWR events interferes with learning in rodents in different experimental paradigms. On the other hand, the cognitive map theory posits that the plastic changes of the firing of hippocampal place cells constitute the electrophysiological counterpart of the spatial learning, observable at the behavioral level. Therefore, we tested whether intact SWR events occurring during t…