Transcriptomic Profile Analysis of Brain Tissue in the Absence of Functional TRPM8 Calcium Channel.

Transient Receptor Potential Melastatin 8 (TRPM8) is a non-selective, Ca-permeable cation channel involved in thermoregulation and other physiological processes, such as basal tear secretion, cell differentiation, and insulin homeostasis. The activation and deactivation of TRPM8 occur through genetic modifications, channel interactions, and signaling cascades. Recent evidence suggests a significant role of TRPM8 in the hypothalamus and amygdala related to pain sensation and sexual behavior.

Intermittent methylphenidate during adolescent development produces locomotor hyperactivity and an enhanced response to cocaine compared to continuous treatment in rats.

The consequences of chronic methylphenidate (MPH) administration in adolescents for the treatment of attention-deficit/hyperactivity disorder (ADHD) remain to be fully understood. Studies in rats indicate that the pharmacokinetics of psychostimulant administration can powerfully influence the behavioral and neural consequences of chronic treatment. The purpose of the present study was to assess the effects of intermittent (0.

Locomotor activity and cocaine-seeking behavior during acquisition and reinstatement of operant self-administration behavior in rats.

Recent studies indicate that administration of dopamine D2-like receptor agonists reinstates drug-seeking behavior in rodents, whereas dopamine D1-like receptor agonists do not. These effects have been related to the ability of these agonists to facilitate the expression of sensitized locomotor activity. Presently, we describe experiments in which locomotor activity was assessed concomitantly with operant performance during acquisition, extinction and reinstatement.

Behavioral depression during cocaine withdrawal is associated with decreased spontaneous activity of ventral tegmental area dopamine neurons.

Withdrawal from an escalating-dose, bingelike regimen of cocaine administration in rats produced significantly depressed levels of locomotor activity during the nocturnal portion of the day-night cycle. This effect was observed during the first 48 hr of testing. Extracellular single-unit recordings of ventral tegmental area (VTA) dopamine (DA) neurons revealed no differences between saline- and cocaine-treated rats with respect to basal firing rates.

Behavioral sensitization to quinpirole is not associated with increased nucleus accumbens dopamine overflow.

This study assessed the relationship between extracellular nucleus accumbens (NAc) dopamine (DA) concentrations and sensitized locomotor activation following repeated administration of the DA D2-like receptor agonist quinpirole. Locomotor activity measures and nucleus accumbens microdialysis samples were collected concurrently in response to the first (acute) and tenth (repeated) quinpirole injection (0.5 mg/kg s.

Repeated ventral tegmental area amphetamine administration alters dopamine D1 receptor signaling in the nucleus accumbens.

Neuroadaptations of the mesoaccumbens dopamine (DA) system likely underlie the emergence of locomotor sensitization following the repeated intermittent systemic administration of amphetamine (AMPH). In the nucleus accumbens (NAc), such neuroadaptations include enhanced DA overflow in response to a subsequent AMPH challenge as well as increased sensitivity to the inhibitory effects of D1 DA receptor (D1R) activation and an altered profile of D1R-dependent induction of immediate early genes (IEGs). Previous results indicate that AMPH acts in the ventral tegmental area (VTA) to initiate those changes leading to sensitization of the locomotor activity and NAc DA overflow produced by systemic administration of this drug.