Adolescence is an important ontogenetic period that is characterized by behaviors such as enhanced novelty-seeking, impulsivity, and reward preference, which can give rise to an increased risk for substance use. While substance use rates in adolescence are generally on a decline, the current rates combined with emerging trends, such as increases in e-cigarette use, remain a significant public health concern. In this review, we focus on the neurobiological divergences associated with adolescent substance use, derived from a cross-sectional, retrospective, and longitudinal studies, and highlight how the use of these substances during adolescence may relate to behavioral and neuroimaging-based outcomes. Identifying and understanding the associations between adolescent substance use and changes in cognition, mental health, and future substance use risk may assist our understanding of the consequences of drug exposure during this critical window.

Two-bottle choice tests are a widely used paradigm in rodents to determine preference between two liquids, with utility for testing animal models of addiction, depression and anhedonia. The following paper describes a 3D-printed, Arduino controlled two-bottle choice test that automatically reads and records drinking behavior in rats to allow for detailed analysis of their drinking microstructure. While commercial products exist use lickometers to measure the microstructure of licking, this design uniquely incorporates hydrostatic depth sensors to allow for real-time volumetric measurements in addition to traditional beam break lick sensing, allowing for licking and drinking microstructure analysis. The goal of this design is to provide a user friendly, affordable apparatus that can study unique, complex behaviors without requiring the purchase of specialized scientific equipment or software. Its applications range from studying alcohol preference in animal models of addiction to sucrose preference in motivational deficits and reward evaluation. This design costs less than $180 CAD to build with decreased cost on each additional device. This design has been successfully tested for accuracy and validated using alcohol preference as an example. The apparatus showed consistency between drinking bouts and volume consumed and is shown to be accurate to ±0.086 ml of the actual volume. This design makes using the two-bottle choice paradigm more accurate, while also making its data more robust and informative while allowing for microstructure analysis of both licking behavior and volume consumed.

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Nicotine and alcohol-containing products are some of the most commonly used substances of abuse and are both leading causes of preventable death. These substances also have significant interactions that have additive and, in some cases, multiplicative effects on the health consequences of their use. Thus, to reduce these negative consequences, it is important to understand the abuse liability of nicotine and alcohol in combination, especially in the most relevant use cases among those who are most vulnerable. Specifically, as tobacco cigarette use is continually decreasing, vaping is quickly replacing cigarettes as the primary mode of nicotine use. This pattern is especially true in adolescent populations in which vaping has grown considerably. Particularly concerning is that adolescents are more vulnerable than adults to the negative consequences of substance use. It is therefore imperative to re-visit the literature as it relates to the rising state of co-use of vaping products with alcohol. Here, we review the clinical outcomes of nicotine and alcohol co-use as they relate to the abuse liability of each individually. Special attention is paid to adolescent findings, where available, as well as investigations that use non-tobacco nicotine products as these may more accurately reflect the more recent trends of co-use. Implications though nicotine alone has previously been considered a proxy for tobacco and tobacco cigarette use, combustible routes of administration have been decreasing. they are, instead, being replaced by e-cigarettes that do not involve other tobacco constituents and contain additional non-nicotine constituents of their own. unfortunately, the literature remains limited with regards to e-cigarettes and their interactions with other substances, especially their prevalent co-use with alcohol. this review attempts to discuss the current literature on nicotine and alcohol co-use in the context of the vaping epidemic, predominantly focusing on addiction-related outcomes and why e-cigarette use may be unique.