LC-NE = locus coeruleus neroepiniphrine
The locus coeruleus is responsible for mediating many of the sympathetic effects during stress. The locus coeruleus is activated by stress, and will respond by increasing norepinephrine secretion, which in turn will alter cognitive function (through the prefrontal cortex), increase motivation (through nucleus accumbens), activate the hypothalamic-pituitary-adrenal axis, and increase the sympathetic discharge/inhibit parasympathetic tone (through the brainstem). Specific to the activation of the hypothalamo-pituitary adrenal axis, norepinephrine will stimulate the secretion of corticotropin-releasing factor] from the hypothalamus, which induces adrenocorticotropic hormone release from the anterior pituitary and subsequent cortisol synthesis in the adrenal glands. Norepinephrine released from locus coeruleus will feedback to inhibit its production, and corticotropin-releasing hormone will feedback to inhibit its production, while positively feeding to the locus coeruleus to increase norepinephrine production.[1]
The LC's role in cognitive function in relation to stress is complex and multi-modal. Norepinephrine released from the LC can act on α2 receptors to increase working memory, or an excess of NE may decrease working memory by binding to the lower-affinity α1 receptors.[2]
LC-NE and ACC may modulate aroused attention in a novel environment and new social environment[3].
There is a strong corrolation between CL firing and wakefulness levels. LC neural activity is highest during wakefulness, progressively lower during non-rapid eye movement (REM) sleep, and nearly absent during REM sleep[4]
References
- ↑ Benarroch EE. The locus ceruleus norepinephrine system: functional organization and potential clinical significance. Neurology. 2009 Nov 17;73(20):1699-704.
- ↑ Ramos BP, Arnsten AF. Adrenergic pharmacology and cognition: focus on the prefrontal cortex. Pharmacol Ther 2007; 113: 523-536.
- ↑ Heinrich S Gompf, Christine Mathai, Patrick M Fuller, David A Wood, Nigel P Pedersen, Clifford B Saper, and Jun Lu, 2011, Locus coeruleus (LC) and anterior cingulate cortex sustain wakefulness in a novel environment, Neurosci. Oct 27, 2010; 30(43): 14543–14551.
- ↑ Aston-Jones G, Bloom FE (1981) Activity of norepinephrine-containing locus coeruleus neurons in behaving rats anticipates fluctuations in the sleep-waking cycle. J Neurosci 1:876–886.