Locus coeruleus activation accelerates perceptual learning

Locus coeruleus involvement in the learning of classically conditioned bradycardia.

Opioid agonists are known to inhibit the activity of locus coeruleus (LC) neurons. In this study, microinjections of the mu-opioid agonist [D-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin (DAMGO; 1.6 microM) bilaterally into the LC caused a significant impairment in the development of a heart-rate (HR) conditioned response (CR). The adverse effect of DAMGO on the HR CR could be reversed with naltrexone ...

Learning, the P3, and the locus coeruleus-norepinephrine system

Stress Accelerates Defensive Responses to Looming in Mice and Involves a Locus Coeruleus-Superior Colliculus Projection

Defensive responses to threatening stimuli are crucial to the survival of species. While expression of these responses is considered to be instinctive and unconditional, their magnitude may be affected by environmental and internal factors. The neural circuits underlying this modulation are still largely unknown. In mice, looming-evoked defensive responses are mediated by the superior colliculu...

Locus coeruleus reports changes in environmental contingencies.

The GANE (glutamate amplifies noradrenergic effects) model proposed by Mather et al. attempts to explain how norepinephrine enhances processing in highly activated brain regions. Careful perusal of the sparse data available from recording studies in animals reveals that noradrenergic neurons are excited mainly by any change in the environment - a salient, novel, or unexpected sensory stimulus o...

Locus Coeruleus and Dopamine-Dependent Memory Consolidation

Most everyday memories including many episodic-like memories that we may form automatically in the hippocampus (HPC) are forgotten, while some of them are retained for a long time by a memory stabilization process, called initial memory consolidation. Specifically, the retention of everyday memory is enhanced, in humans and animals, when something novel happens shortly before or after the time ...