Intensifying Substance Use Trends among Youth: A Narrative Review of Recent Trends and Implications.

Purpose Of Review: Substance use among adolescents and young adults remains a critical public health concern, with patterns shifting dramatically in recent years. This narrative review examines trends in substance use behaviors during and following the COVID-19 pandemic.

Recent Findings: Epidemiologic evidence shows declines in the proportion of youth who are using most substances but intensified consumption patterns with rising levels of disorder among adolescents who use substances.

α-adrenergic heteroreceptors are required for stress-induced reinstatement of cocaine conditioned place preference.

The α-adrenergic receptor (α-AR) agonist guanfacine has been investigated as a potential treatment for substance use disorders. While decreasing stress-induced reinstatement of cocaine seeking in animal models and stress-induced craving in human studies, guanfacine has not been reported to decrease relapse rates. Although guanfacine engages α-AR autoreceptors, it also activates excitatory G-coupled heteroreceptors in the bed nucleus of the stria terminalis (BNST), a key brain region in driving stress-induced relapse.

mGlu and mGlu Negative Allosteric Modulators Divergently Enhance Thalamocortical Transmission and Exert Rapid Antidepressant-like Effects.

Non-selective antagonists of metabotropic glutamate receptor subtypes 2 (mGlu) and 3 (mGlu) exert rapid antidepressant-like effects by enhancing prefrontal cortex (PFC) glutamate transmission; however, the receptor subtype contributions and underlying mechanisms remain unclear. Here, we leveraged newly developed negative allosteric modulators (NAMs), transgenic mice, and viral-assisted optogenetics to test the hypothesis that selective inhibition of mGlu or mGlu potentiates PFC excitatory transmission and confers antidepressant efficacy in preclinical models. We found that systemic treatment with an mGlu or mGlu NAM rapidly activated biophysically unique PFC pyramidal cell ensembles.

Disabling the Gβγ-SNARE interaction disrupts GPCR-mediated presynaptic inhibition, leading to physiological and behavioral phenotypes.

G protein-coupled receptors (GPCRs) that couple to G proteins modulate neurotransmission presynaptically by inhibiting exocytosis. Release of Gβγ subunits from activated G proteins decreases the activity of voltage-gated Ca channels (VGCCs), decreasing excitability. A less understood Gβγ-mediated mechanism downstream of Ca entry is the binding of Gβγ to SNARE complexes, which facilitate the fusion of vesicles with the cell plasma membrane in exocytosis.

Dorsal BNST α-Adrenergic Receptors Produce HCN-Dependent Excitatory Actions That Initiate Anxiogenic Behaviors.

Stress is a precipitating agent in neuropsychiatric disease and initiates relapse to drug-seeking behavior in addicted patients. Targeting the stress system in protracted abstinence from drugs of abuse with anxiolytics may be an effective treatment modality for substance use disorders. α-adrenergic receptors (α-ARs) in extended amygdala structures play key roles in dampening stress responses.

Synaptic Plasticity in the Bed Nucleus of the Stria Terminalis: Underlying Mechanisms and Potential Ramifications for Reinstatement of Drug- and Alcohol-Seeking Behaviors.

The bed nucleus of the stria terminalis (BNST) is a component of the extended amygdala that shows significant changes in activity and plasticity through chronic exposure to drugs and stress. The region is critical for stress- and cue-induced reinstatement of drug-seeking behaviors and is thus a candidate region for the plastic changes that occur in abstinence that prime addicted patients for reinstatement behaviors. Here, we discuss the various forms of long-term potentiation (LTP) and long-term depression (LTD) in the rodent BNST and highlight the way that these changes in excitatory transmission interact with exposure to alcohol and other drugs of abuse, as well as other stressors.

New roles for icosahedral clusters in intermetallic phases: micelle-like segregation of Ca-Cd and Cu-Cd interactions in Ca10Cd27Cu2.

Despite significant progress in the structural characterization of the quasicrystalline state, the chemical origins of long- and short-range icosahedral order remain mysterious and a subject of debate. In this Article, we present the crystal structure of a new complex intermetallic phase, Ca10Cd27Cu2 (mC234.24), whose geometrical features offer clues to the driving forces underlying the icosahedral clusters that occur in Bergman-type quasicrystals.