1. The effect of varying the extracellular Ca2+ concentration on basal and acetylcholine (ACh)-induced release nitric oxide (NO) from rabbit aorta was investigated by use a superfusion bioassay system. 2. Changes between 0.5 2.0 mM in superfusing detector tissues or perfusing endothelium-denuded donor aortae had no tone these tissues. 3. Increasing endothelium-containing zero to 1.25 caused transient (24 +/- 9 min), concentration-dependent NO, which attenuated at higher concentrations...

Learning and adaptation during sources of threat safety are critical mechanisms for survival. The prelimbic (PL) infralimbic (IL) subregions the medial prefrontal cortex (mPFC) have been broadly implicated in processing safety. However, how these regions regulate naturalistic conditions involving thermal challenge still remains elusive. To examine this issue, we developed a novel paradigm which adult mice learned that particular zone was identified with visuospatial cues associated either...

Often, retrieval cues are not uniquely related to one specific memory, which could lead memory interference. Controlling interference is particularly important during episodic or when remembering events in a spatiotemporal context. Despite clear involvement of prefrontal cortex (PFC) human studies, information regarding the mechanisms and neurotransmitter systems PFC involved scarce. Although serotoninergic system has been linked functionality modulation, its role processing poorly...

The retrosplenial cortex (RSC) is involved in a range of cognitive functions. However, its precise involvement memory processing unknown. Pharmacological and behavioral experiments demonstrate that protein synthesis c-Fos expression the anterior part RSC (aRSC) are necessary late after training to maintain for many days fear-motivated memory. Long-lasting storage regulated by D1/D5 dopamine receptors aRSC depends on functional interplay between dorsal hippocampus aRSC. These results suggest...

Therapies based on the impairment of reconsolidation or enhancement extinction offer possibility decreasing persistent recollection distressing memories. However, direct interplay between and has rarely been considered. Previously, we reported that reactivation induces fear memory. Here, using a step-down inhibitory avoidance learning paradigm in rats, show intrahippocampus infusion function-blocking anti-BDNF antibody immediately 6 h after memory impairs extinction. Extinction increases pro...

ABSTRACT Object recognition memory (ORM) is a hippocampus‐dependent form of essential for distinguishing items and constructing episodic representations the past. Ca2+/calmodulin‐dependent protein kinase II (CaMKII) serine/threonine‐specific highly enriched in hippocampal formation, where it acts as memory‐relevant calcium effector. We found that, rats, training an ORM inducing learning task rapidly increased CaMKII autophosphorylation CA1 region dorsal hippocampus. Moreover, early...

Interleukin 1 alpha (IL-1 alpha), a powerful endogenous pyrogen released from monocytes and macrophages by bacterial endotoxin, stimulates corticotropin, prolactin, somatotropin release inhibits thyrotropin hypothalamic action. We injected recombinant human IL-1 into the third cerebral ventricle, to study its effect on pulsatile of follicle-stimulating hormone (FSH) luteinizing (LH) in conscious, freely moving, ovariectomized rats. Intraventricular injection 0.25 pmol caused an almost...

Medial prefrontal cortex (mPFC) is essential for initial memory processing and expression but its involvement in persistent storage has seldom been studied. Using the hippocampus dependent inhibitory avoidance learning task hippocampus-independent conditioned taste aversion paradigm together with specific dopamine receptor agonists antagonists we found that persistence not formation of long-tem aversive memories requires D1/D5 receptors activation mPFC immediately after training and,...

The Lateral Habenula (LHb) is a small brain structure that codifies negative motivational value and has been related to major depression. It shown recently LHb activation sufficient induce aversive associative learning; however the key question about whether required for an memory be formed not addressed. In this article we studied function of in formation using Inhibitory Avoidance task (IA). We found inactivation during IA training does disrupt when assessed 24 h after, but abolishes it 7...

Avoidance memory reactivation at recall triggers theta-gamma hippocampal phase amplitude coupling (hPAC) only when it elicits hippocampus-dependent reconsolidation. However, is not known whether there a causal relationship between these phenomena. We found that in adult male Wistar rats, silencing the medial septum during did affect avoidance expression or maintenance but abolished hPAC and amnesia caused by intrahippocampal administration of reconsolidation blockers, both which were...

Consolidation and reconsolidation are independent memory processes. stabilizes new memories, whereas restabilizes memories destabilized when reactivated during recall. However, the biological role of destabilization/reconsolidation cycle is still unknown. It has been hypothesized that links information with but some reports suggest old associated through consolidation mechanisms instead. Object-recognition (ORM) serves to judge familiarity items essential for remembering previous events. We...

Object recognition memory (ORM) allows identification of previously encountered items and is therefore crucial for remembering episodic information. In rodents, reactivation during recall in the presence a novel object destabilizes ORM initiates Zif268 protein synthesis-dependent reconsolidation process hippocampus that links this to reactivated trace. Hippocampal NMDA receptors (NMDARs) modulate expression synthesis regulate stability but their possible involvement...

Object recognition memory (ORM) confers the ability to discriminate familiarity of previously encountered items. Reconsolidation is process by which reactivated memories become labile and susceptible modifications. The hippocampus specifically engaged in reconsolidation integrate new information into original ORM through a mechanism involving activation brain-derived neurotrophic factor (BDNF) signaling induction LTP. It known that BDNF can control LTP maintenance protein kinase Mζ (PKMζ),...

Abstract Extinction memory destabilized by recall is restabilized through mTOR-dependent reconsolidation in the hippocampus, but upstream pathways controlling these processes remain unknown. Hippocampal NMDARs drive local protein synthesis via mTOR signaling and may control active maintenance. We found that adult male Wistar rats, intra dorsal-CA1 administration of non-subunit selective NMDAR antagonist AP5 or GluN2A subunit-containing TCN201 after step down inhibitory avoidance (SDIA)...

The effects of vasopressin on the cerebral circulation were studied in conscious goats and isolated human goat arteries. Infusion 1 to 12 mU into internal maxillary artery unanesthetized caused dose-dependent reductions blood flow, a decrease 36 +/- 4.7% (mean S.E.) occurring with highest dose. Cumulative application (10(-12) 10(-6) M) markedly constricted arteries vitro, effect being more prominent vessels. (1-Deaminopenicillamine, 4-valine)-8-D-arginine-vasopressin, competitive antagonist...

Abstract Object recognition memory (ORM) serves to distinguish familiar items from novel ones. Reconsolidation is the process by which active memories are updated. The hippocampus engaged in ORM reconsolidation through a mechanism involving induction of long-term potentiation (LTP). transcription factor Zif268 essential for hippocampal LTP maintenance and has been frequently associated with processes. However, its possible involvement not determined conclusively. Using antisense...