Dorsal subcoeruleus nucleus (SubCD) involvement in context-associated fear memory consolidation.

The neurobiological mechanisms of emotional memory processing can be investigated using classical fear conditioning as a model system, and evidence from multiple lines of research suggests that sleep influences consolidation of emotional memory. In rodents, some of this evidence comes from a common finding that sleep deprivation from 0 to 6 h after fear conditioning training impairs processing of conditioned fear memory. Here, we show that during a 6-h session of sleep-wake (S-W) recording, immediately after a session of context-associated fear conditioning training, rats spent more time in wakefulness (W) and less time in slow-wave sleep (SWS) and rapid eye movement (REM) sleep.

A novel role for calcium/calmodulin kinase II within the brainstem pedunculopontine tegmentum for the regulation of wakefulness and rapid eye movement sleep.

Considerable evidence suggests that the brainstem pedunculopontine tegmentum (PPT) neurons are critically involved in the regulation of rapid eye movement (REM) sleep and wakefulness (W); however, the molecular mechanisms operating within the PPT to regulate these two behavioral states remain relatively unknown. Here we demonstrate that the levels of calcium/calmodulin kinase II (CaMKII) and phosphorylated CaMKII expression in the PPT decreased and increased with 'low W with high REM sleep' and 'high W/low REM sleep' periods, respectively. These state-specific expression changes were not observed in the cortex, or in the immediately adjacent medial pontine reticular formation.

Improvement of two-way active avoidance memory requires protein kinase a activation and brain-derived neurotrophic factor expression in the dorsal hippocampus.

Previous studies have shown that two-way active avoidance (TWAA) memory processing involves a functional interaction between the pontine wave (P wave) generator and the CA3 region of the dorsal hippocampus (DH-CA3). The present experiments examined whether the interaction between P wave generator activity and the DH-CA3 involves the intracellular protein kinase A (PKA) signaling system. In the first series of experiments, rats were subjected to a session of TWAA training followed immediately by bilateral microinjection of either the PKA activation inhibitor (KT-5720) or vehicle control into the DH-CA3 and tested for TWAA memory 24 h later.

Spontaneous REM sleep is modulated by the activation of the pedunculopontine tegmental GABAB receptors in the freely moving rat.

Considerable evidence suggests that the neurotransmitter gamma-aminobutyric acid (GABA)-ergic system and pedunculopontine tegmentum (PPT) in the brain stem are critically involved in the regulation of rapid-eye-movement (REM) sleep. GABA and its various receptors are normally present in the PPT cholinergic cell compartment. The aim of this study was to identify the role of GABA and its receptors in the regulation of REM sleep.

Effects of passive-avoidance training on sleep-wake state-specific activity in the basolateral and central nuclei of the amygdala.

This study examined the effects of intense emotional learning on the sleep-wake state-specific electroencephalographic (EEG) activities of the basolateral (BLA) and central (CeA) nuclei of the amygdala. Rats were trained on a passive-avoidance learning (PAL) protocol that was followed by 6 hr of undisturbed polygraphic recording and a PAL test. After PAL training, the total amount of REM sleep decreased: high-frequency EEG power decreased in the CeA during REM sleep and increased in the BLA during all sleep-wake stages.

Choline availability during embryonic development alters the localization of calretinin in developing and aging mouse hippocampus.

Choline availability in the diet during pregnancy alters fetal brain biochemistry with resulting behavioral changes that persist throughout the lifetime of the offspring. In the present study, the effects of dietary choline on the onset of GABAergic neuronal differentiation in developing fetal brain, as demarcated by the expression of calcium binding protein calretinin, are described. In these studies, timed-pregnant mice were fed choline supplemented, control or choline deficient AIN-76 diet from day 12-17 of pregnancy and the brains of their fetuses were studied on day 17 of gestation.

Single cell activity patterns of pedunculopontine tegmentum neurons across the sleep-wake cycle in the freely moving rats.

Microinjections of the excitatory amino acid, L-glutamate into the cholinergic cell compartment of the pedunculopontine tegmentum (PPT) of the rat induces both wakefulness and/or rapid eye movement (REM) sleep depending on the glutamate dosage. However, no studies have systematically recorded the electrical activity of these cells in the freely moving rat across the sleep-wake cycle. In this study, we have recorded the spontaneous activity patterns of single PPT cells (n = 70) in the freely moving rat across the sleep-wake cycle.