Extraversion has two central characteristics:(1) interpersonal engagement, which consists of
affiliation (enjoying and valuing close interpersonal bonds, being warm and affectionate) …

Many of the brain's reward systems converge on the nucleus accumbens, a region richly
innervated by excitatory, inhibitory, and modulatory afferents representing the circuitry …

Repeated exposure to drugs of abuse enhances the motor-stimulant response to these
drugs, a phenomenon termed behavioral sensitization. Animals that are extinguished from …

primate research suggests that affiliation is a highly complex construct. studies of primate
affiliation demonstrate the need to distinguish between various affiliative behaviors, consider …

cAMP (3′, 5′ cyclic adenosine monophosphate) is a second messenger that in eukaryotic
cells induces physiological responses ranging from growth, differentiation, and gene …

Drug seeking and drug self-administration in both animals and humans can be triggered by
drugs of abuse themselves or by stressful events. Here, we demonstrate that in vivo …

How do drugs of abuse modify neural circuitry and thereby lead to addictive behaviour? As
for many forms of experience-dependent plasticity, modifications in glutamatergic synaptic …

Rationale and objectives: Repeated exposure to many drugs of abuse results in a
progressive and enduring enhancement in the motor stimulant effect elicited by a …

Repeated exposure to psychostimulants such as cocaine and amphetamine produces
behavioral sensitization, which is characterized by an augmented locomotor response to a …

Drug addiction results from adaptations in specific brain neurons caused by repeated
exposure to a drug of abuse. These adaptations combine to produce the complex behaviors …