Dopamine modulation of nucleus accumbens (NAc) circuitry is central to theories of reward seeking and reinforcement learning. Despite decades of effort, the acute dopamine actions on the NAc microcircuitry remain puzzling. Here, we dissect out the direct actions of dopamine on lateral inhibition between medium spiny neurons (MSNs) in mouse brain slices and find that they are pathway specific. Dopamine potently depresses GABAergic transmission from presynaptic dopamine D2 receptor-expressing MSNs (D2-MSNs), whereas it potentiates transmission from presynaptic dopamine D1 receptor-expressing MSNs (D1-MSNs) onto other D1-MSNs. To our surprise, presynaptic D2 receptors mediate only half of the depression induced by endogenous and exogenous dopamine. Presynaptic serotonin 5-HT1B receptors are responsible for a significant component of dopamine-induced synaptic depression. This study clarifies the mechanistic understanding of dopamine actions in the NAc by showing pathway-specific modulation of lateral inhibition and involvement of D2 and 5-HT1B receptors in dopamine depression of D2-MSN synapses.
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http://dx.doi.org/10.1016/j.celrep.2022.110795 | DOI Listing |
Eur J Neurol
January 2025
Department of Pharmacotherapy, University of Utah Health, Salt Lake City, Utah, USA.
Background: Reduction of intracellular Na accumulation through late Na current inhibition has been recognized as a target for cardiac Ca handling which underlies myocardial contractility and relaxation in heart failure (HF). Riluzole, an Na channel blocker with enhancement of Ca-activated K channel function, used for management of amyotrophic lateral sclerosis (ALS), is effective in suppressing Ca leak and therefore may improve cardiac function.
Objectives: The study aim was to investigate whether riluzole lowers HF incidence.
Navigating visually complex environments requires focusing on relevant information while filtering out (salient) distractions. The signal suppression hypothesis posits that salient stimuli generate an automatic saliency signal that captures attention unless overridden by learned suppression mechanisms. In support of this, ERP studies have demonstrated that salient stimuli that do not capture attention elicit a distractor positivity (PD), a putative neural index of suppression.
View Article and Find Full Text PDFNeuroscience
January 2025
Center for Neuroscience, Indian Institute of Science, Bengaluru 560012, India. Electronic address:
Pain and itch are unpleasant and distinct sensations that give rise to behaviors such as reflexive withdrawal and scratching in humans and mice. Interestingly, it has been observed that pain modulate itch through the neural circuits housed in the brain and spinal cord. However, we are yet to fully understand the identities of, and mechanisms by which specific neural circuits mediate pain-induced modulation of itch.
View Article and Find Full Text PDFFree Radic Biol Med
January 2025
Graduate School of Life and Medical Sciences, Doshisha University, 1-3 Miyakodani, Tatara, Kyotanabe, Kyoto 610-0394, Japan. Electronic address:
Enzymatically formed side-chain oxysterols function as signaling molecules regulating cholesterol homeostasis and act as intermediates in the biosynthesis of bile acids. In addition to these physiological functions, an imbalance in oxysterol homeostasis has been implicated in pathophysiology. Cholesterol 25-hydroxylase (CH25H) and its product 25-hydroxycholesterol (25-OHC), also formed by autoxidation, are associated with amyotrophic lateral sclerosis.
View Article and Find Full Text PDFCell Rep
January 2025
Department of Clinical Neurological Sciences, London Health Sciences Centre, Western University, London, ON, Canada; Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Western Institute for Neuroscience, Western University, London, ON, Canada.
Cortical neurons in brain slices display intrinsic spike frequency adaptation (I-SFA) to constant current inputs, while extracellular recordings show extrinsic SFA (E-SFA) during sustained visual stimulation. Inferring how I-SFA contributes to E-SFA during behavior is challenging due to the isolated nature of slice recordings. To address this, we recorded macaque lateral prefrontal cortex (LPFC) neurons in vivo during a visually guided saccade task and in vitro in brain slices.
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