Arousal and drug abuse

Abstract

The reticular activating system (RAS) is not an amorphous region but distinct nuclei with specific membrane properties that dictate their firing during waking and sleep. The locus coeruleus and raphe nucleus fire during waking and slow wave sleep, with the pedunculopontine nucleus (PPN) firing during both waking and REM sleep, the states manifesting arousal-related EEG activity. Two important discoveries in the PPN in the last 10 years are, 1) that some PPN cells are electrically coupled, and 2) every PPN cell manifests high threshold calcium channels that allow them to oscillate at beta/gamma band frequencies. The role of arousal in drug abuse is considered here in terms of the effects of drugs of abuse on these two mechanisms. Drug abuse and the perception of withdrawal/relapse are mediated by neurobiological processes that occur only when we are awake, not when we are asleep. These relationships focus on the potential role of arousal, more specifically of RAS electrical coupling and gamma band activity, in the addictive process as well as the relapse to drug use.

Prepronociceptin-Expressing Neurons in the Extended Amygdala Encode and Promote Rapid Arousal Responses to Motivationally Salient Stimuli

“…Dysfunctional arousal responses are a core component of many neuropsychiatric disorders. For example, patients with anxiety disorders often show hyperarousal responses to negatively salient stimuli, and patients suffering from depression show hypoarousal responses to positively salient stimuli ( Craske et al, 2009 ; Lang and McTeague, 2009 ; Patriquin et al, 2019 ; Schmidt et al, 2017 ; Urbano et al, 2017 ; Wilhelm and Roth, 2001 ). Elucidating the neural circuit elements that orchestrate changes in physiological arousal is, thus, essential for understanding maladaptive motivational states ( Marton and Sohal, 2016 ; Sparta et al, 2013 ; Touriño et al, 2013 ).…”

Prepronociceptin expressing neurons in the extended amygdala encode and promote rapid arousal responses to motivationally salient stimuli

“…Dysfunctional arousal responses are a core component of many neuropsychiatric disorders. For example, patients with anxiety disorders often show hyperarousal responses to negatively salient stimuli, and patients suffering from depression show hypoarousal responses to positively salient stimuli (Craske et al, 2009;Lang and McTeague, 2009;Patriquin et al, 2019;Schmidt et al, 2017;Urbano et al, 2017;Wilhelm and Roth, 2001). Elucidating the neural circuit elements that orchestrate changes in physiological arousal are thus essential for understanding maladaptive motivational states (Marton and Sohal, 2016;Sparta et al, 2013;Touriño et al, 2013).…”

Drugs of Abuse and Addiction - Overview and Current Status

“…Long-term drug abuse impairs brain functioning accordingly. Drug of abuse mend signaling of intracellular messengers, and more important, the neurotransmitter systems [6,77]. The abused user normally feels depressed, lifeless, flat and less pleasurable than before they take and abuse drugs.…”

“…Bodybuilders and some athletes normally get addicted anabolic steroids to enhance athletic performance and add to their muscle mass. The most commonly abused groups of drugs are those that act on the CNS to cause intense feelings of euphoria or alter perception [1,6].…”