Arousal norepinephrine

Harley, CW (1987) A role for norepinephrine in arousal, emotion and learning limbic modulation by norepinephrine and the Kety hypothesis. Prog. Neuro-Psychopharmacol. Biol. Psychiat. 11 419-458. 

Although this drug is categorized as a local anesthetic, I have chosen to put it in with the hallucinogens because of the psychotomimetic effects that it produces. Cocaine is not a phenylethyl-amine, but it produces central nervous system arousal or stimulant effects which closely resemble those of the amphetamines, the methylenedioxyamphetamines in particular. This is due to the inhibition by cocaine of re-uptake of the norepinephrine released by the adrenergic nerve terminals, leading to an enhanced adrenergic stimulation of norepinephrine receptors. The increased... 

Norepinephrine (also called noradrenaline)—Controls emotional arousal and increases attention. 

But the fact that we experience anxiety—often of panic proportions in our REM sleep dreams when the locus coeruleus is shut down completely—means two things that arousal—at least in the waking sense of the term—and anxiety are completely dissociable and that the brain-mind is capable of generating anxiety without the help of the locus coeruleus In fact, REM sleep dream anxiety cannot depend upon norepinephrine, or serotonin, or histamine either, which leaves dopamine and acetylcholine as the only two neuromodulatory candidates for... 

Although arousal is usually considered to be a state of increased dopamine and norepinephrine and inattentiveness is considered to reflect deficiencies in these neurotransmitters in these pathways, this is only somewhat true even in persons without a cognitive disorder. Thus, more of these neurotransmitters will enhance attention, but only to a certain extent. Too much of a good thing, like dopamine or norepinephrine, will actually lead to deterioration in cognitive performance. Thus, hyperarousal is more likely to be associated with inability to concentrate than with heightened attention span. 

The norepinephrine neurons living in your locus coeruleus project throughout your brain. This broad access allows them to influence your level of arousal and thus almost every aspect of your thinking and behavior. Consistent with this role, it has recently been discovered that schizophrenic patients who display a chronic state of hyperarousal have significantly more norepinephrine neurons in their brains. 

By now you have a sense of the interwoven roles of dopamine, norepinephrine, and acetylcholine in the control of movement, reward, mood, arousal, and learning and attention. By considering how various drugs manipulate these neurotransmitter systems within the brain, scientists have discovered some consistent patterns that allow us to make predictions about what to expect when specific types of drugs are taken. The same holds true for the neurotransmitter system mentioned several times in this chapter serotonin. What are the consequences of its manipulation in the brain Read on. 

EDS is usually treated using amphetamine-like CNS stimulants or modaflnil, a novel wake-promoting compound unrelated to amphetamines. The most commonly used amphetamine-like compounds aremethamphetamine, D-amphetamine, methylpheni-date, pemoline, and mazindol. The most important pharmacological property of these compounds is to release catecholamines, i.e., dopamine and norepinephrine. Amphetamine-like compounds also share the property of blocking the reuptake and the degradation of these monoamines (monoamine oxidase inhibition at high doses). All these properties presynaptically enhance dopamine transmission, which are likely to contribute to the EEG arousal effects of amphetamines. 

This effect is not surprising Amphetamines are potent psychomotor stimulants. Whether sniffed, swallowed, snorted, or injected, they induce feelings of power, strength, exhilaration, self-assertion, focus, and enhanced motivation. Amphetamine intake causes a release of the excitatory neurotransmitters dopamine and noradrenaline (norepinephrine) in the central nervous system (CNS). The release of dopamine typically induces a sense of aroused euphoria that may last several hours unlike cocaine, amphetamine is not readily broken down by the body. After taking amphetamines, feelings are intensified, the need to sleep or eat is diminished, and the user may feel as though he or she can take on the world. ... 

Methamphetamine (MAP) is a psychostimulant that induces enhanced arousal and euphoria acutely, and psychosis and addiction chronically. MAP enters the terminals/neuron via the monoamine transporters (dopamine transporter DAT, serotonin transporter SERT, or norepinephrine transporter NET), displaces... 

When animals are exposed to inescapable shock, they exhibit consistent behavioral reactions—initially hypervigilance or arousal and ultimately a profound state of withdrawal and "depression." In addition, such animals eventually show a significant depletion of norepinephrine, likely accompanied by changes in NE receptor sensitivity in parts of the brain. Alterations of receptor sensitivity may leave the animals in a state of chronic hyperarousal. In essence, their nervous systems may be permanently altered such that traumatized animals and people alike are relatively unable to dampen or inhibit excessive emotional arousal. Antidepressants that affect norepinephrine appear to alter receptor sensitivity, both in humans and animals. Serotonergic antidepressants may also indirectly inhibit hypersensitive NE cells (Nagy et al. 1993), and thus can play a role in treating hyperarousal in PTSD patients. 

Effective treatments modulate dopamine (DA) and norepinephrine (NE) to improve executive functioning and regulate arousal for improved performance. The chnical response associated with stimulants is not paradoxical, and is not diagnostic for ADHD because stimulants can increase attention, decrease motor activity, and improve learning tasks in those with subclinical ADHD or in individuals with such problems from other sources (e.g., fatigue). ... 

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