Ventral Tegmental Area Amylin Receptor Activation Differentially Modulates Mesolimbic Dopamine Signaling in Response to Fat versus Sugar.

Amylin, a pancreatic hormone that is cosecreted with insulin, has been highlighted as a potential treatment target for obesity. Amylin receptors are distributed widely throughout the brain and are coexpressed on mesolimbic dopamine neurons. Activation of amylin receptors is known to reduce food intake, but the neurochemical mechanisms behind this remain to be elucidated.

Distinct Effects of Methamphetamine Isomers on Limbic Norepinephrine and Dopamine Transmission in the Rat Brain.

Methamphetamine (METH) is a psychostimulant that primarily exerts its effects on the catecholamine (dopamine (DA) and norepinephrine (NE)) systems, which are implicated in drug addiction. METH exists as two distinct enantiomers, dextrorotatory (d) and levorotatory (l). In contrast to d-METH, the major component of illicit METH used to induce states of euphoria and alertness, l-METH is available without prescription as a nasal decongestant and has been highlighted as a potential agonist replacement therapy to treat stimulant use disorder.

Distinct limbic dopamine regulation across olfactory-tubercle subregions through integration of in vivo fast-scan cyclic voltammetry and optogenetics.

The olfactory tubercle (OT), an important component of the ventral striatum and limbic system, is involved in multi-sensory integration of reward-related information in the brain. However, its functional roles are often overshadowed by the neighboring nucleus accumbens. Increasing evidence has highlighted that dense dopamine (DA) innervation of the OT from the ventral tegmental area (VTA) is implicated in encoding reward, natural reinforcers, and motivated behaviors.

Distinct dose-dependent effects of methamphetamine on real-time dopamine transmission in the rat nucleus accumbens and behaviors.

Methamphetamine (METH) is a potent psychostimulant that exerts many of its physiological and psychomotor effects by increasing extracellular dopamine (DA) concentrations in limbic brain regions. While several studies have focused on how potent, neurotoxic doses of METH augment or attenuate DA transmission, the acute effects of lower and behaviorally activating doses of METH on modulating DA regulation (release and clearance) through DA D2 autoreceptors and transporters remain to be elucidated. In this study, we investigated how systemic administration of escalating, subneurotoxic doses of METH (0.

Chemogenetic activation of ventral tegmental area GABA neurons, but not mesoaccumbal GABA terminals, disrupts responding to reward-predictive cues.

Cues predicting rewards can gain motivational properties and initiate reward-seeking behaviors. Dopamine projections from the ventral tegmental area (VTA) to the nucleus accumbens (NAc) are critical in regulating cue-motivated responding. Although, approximately one third of mesoaccumbal projection neurons are GABAergic, it is unclear how this population influences motivational processes and cue processing.

Noradrenergic Modulation of Dopamine Transmission Evoked by Electrical Stimulation of the Locus Coeruleus in the Rat Brain.

Central norepinephrine (NE) and dopamine (DA) are involved in a variety of physiological functions and behaviors. Accumulating evidence suggests that NE neurons originating from the locus coeruleus (LC) innervate DA neurons of the ventral tegmental area (VTA) and influence VTA-DA neural activity. However, the underlying mechanisms of how LC-NE regulates DA transmission via VTA-DA neurons remain largely unexplored.

Heterogeneous extracellular dopamine regulation in the subregions of the olfactory tubercle.

Recent studies show that dense dopamine (DA) innervation from the ventral tegmental area to the olfactory tubercle (OT) may play an important role in processing multisensory information pertaining to arousal and reward, yet little is known about DA regulation in the OT. This is mainly due to the anatomical limitations of conventional methods of determining DA dynamics in small heterogeneous OT subregions located in the ventral most part of the brain. Additionally, there is increasing awareness that anteromedial and anterolateral subregions of the OT have distinct functional roles in natural and psychostimulant drug reinforcement as well as in regulating other types of behavioral responses, such as aversion.