Cyclic AMP Mediates Serotonin-Induced Synaptic Enhancement of Lateral Giant Interneuron of the Crayfish

2005 ◽  
Vol 94 (4) ◽  
pp. 2644-2652 ◽  
Author(s):  
Makoto Araki ◽  
Toshiki Nagayama ◽  
Jordanna Sprayberry
Keyword(s):  
Biogenic Amines ◽  
Time Course ◽  
Neural Circuit ◽  
Escape Behavior ◽  
Direct Injection ◽  
Phosphodiesterase Inhibitor ◽  
Sensory Stimulation ◽  
Simultaneous Application ◽  
Camp Analogue ◽  
Repetitive Sensory Stimulation

The lateral giant (LG)-mediated escape behavior of the crayfish habituates readily on repetitive sensory stimulation. Recent studies suggested that the biogenic amines serotonin and octopamine modulate the time course of recovery and/or re-depression of the LG response after habituation. However, little is known of how serotonin and octopamine effect LG habituation and what second-messenger cascades they may activate. To investigate the effect of biogenic amines on LG habituation, serotonin and octopamine were superfused before presenting repetitive sensory stimulation. Serotonin and octopamine increased the number of stimuli needed to habituate the LG response. Their effects were mimicked by mixed application of a cAMP analogue [8-(4-chlorophenylthio)-cAMP (CPT-cAMP)] and a phosphodiesterase inhibitor [3-isobutyl-1-methylxanthine (IBMX)] but not by a cGMP analogue (8-bromoguanosine 3′,5′-cyclic monophosphate). Perfusion of the adenylate cyclase inhibitor (SQ22536) abolished the effect of serotonin but not that of octopamine. To investigate the site of action of each biogenic amines in the neural circuit meditating LG escape, the effect of drugs on directly and indirectly elicited postsynaptic potentials in LG was investigated. Serotonin, octopamine, and a mixture of CPT-cAMP and IBMX increased both the direct and indirect synaptic inputs. Simultaneous application of SQ22536 abolished the effect of serotonin on both inputs but did not block the effect of octopamine. Direct injection of the cAMP analogue (Sp-isomer of adenosine-3′,5′-cyclic monophosphorothioate) into LG increased both the direct and indirect inputs to LG. These results indicate that serotonin mediates an increase in cAMP levels in LG, but octopamine acts independently of cAMP and cGMP.

Protein secretion induced by isoproterenol or pentoxifylline in lacrimal gland: Ca2+ effects

1984 ◽  
Vol 246 (1) ◽  
pp. C37-C44 ◽  
Author(s):  
P. Mauduit ◽  
G. Herman ◽  
B. Rossignol
Keyword(s):  
Protein Secretion ◽  
Lacrimal Gland ◽  
Adrenergic Receptors ◽  
Time Course ◽  
Phosphodiesterase Inhibitor ◽  
Extracellular Calcium ◽  
Maximal Response ◽  
Beta Adrenergic Receptors ◽  
Beta Adrenergic ◽  
Camp Analogue

In exorbital lacrimal glands, pentoxifylline (a methylxanthine) induces labeled protein secretion in a dose-related manner: the half-maximal and maximal stimulations are at 4 and 10 mM, respectively. In the presence of papaverine (10(-5) M), a phosphodiesterase inhibitor, labeled protein discharge is strongly stimulated by isoproterenol, via beta-adrenergic receptors: the maximal response is at 10(-6) M. l-Propranolol specifically inhibits the secretory stimulation to isoproterenol in a dose-related manner: for 5 X 10(-6) M isoproterenol in the presence of 10(-5) M papaverine, the half-maximal and maximal inhibitions are at 3 X 10(-7) and 10(-5) M, respectively. The beta-adrenergic response is mimicked by the adenosine 3',5'-cyclic monophosphate (cAMP) analogue dibutyryl cAMP (DBcAMP) at a 10(-3) M concentration. The time course of labeled protein secretion induced by pentoxifylline, DBcAMP, and isoproterenol shows a latency. In the presence or absence of extracellular calcium, pentoxifylline and isoproterenol immediately increase the cAMP intracellular level. Extracellular calcium omission increases the observed latency and also affects the maximal rate of protein secretion. As opposed to the cholinergic agonist, pentoxifylline has only a slight but sustained effect on 45Ca efflux, whereas isoproterenol has none. These data suggest that labeled protein secretion, such as that of peroxidase, can also be stimulated in rat exorbital lacrimal gland, through beta-adrenergic receptors; in the stimulation evoked by a beta-adrenergic agonist, DBcAMP, or methylxanthine, calcium could play a key role.

scholarly journals Involvement of cyclic AMP in multiple, excitatory actions of biogenic amines on the cardiac ganglion of the horseshoe crab Limulus polyphemus

1990 ◽  
Vol 152 (1) ◽  
pp. 313-331
Author(s):  
J. R. Groome ◽  
W. H. Watson
Keyword(s):  
Cyclic Amp ◽  
Biogenic Amines ◽  
Time Course ◽  
Phosphodiesterase Inhibitor ◽  
Nucleotide Metabolism ◽  
Muscle Fibres ◽  
Cardiac Ganglion ◽  
Biochemical Effect ◽  
Pharmacological Agents ◽  
Dose Dependent

Cyclic AMP appears to be involved in several excitatory actions of amines on neurones of the Limulus cardiac ganglion. Amines selectively increase levels of cardiac ganglion cyclic AMP with a magnitude and time course similar to that observed for amine-induced excitation of cardiac ganglion burst rate. With respect to either the physiological or biochemical effect, the apparent order of potency is octopamine greater than epinephrine approximately dopamine greater than norepinephrine. Elevation of cardiac ganglion cyclic AMP levels by octopamine or dopamine is dose-dependent and is potentiated by the phosphodiesterase inhibitor 3-isobutyl 1-methylxanthine (IBMX). Several pharmacological agents which influence cyclic nucleotide metabolism, including forskolin, IBMX and 8-substituted cyclic AMP analogues, have amine-like effects on the Limulus cardiac ganglion. These effects include increased burst rate of the isolated cardiac ganglion and decreased burst duration, interburst interval and number of spikes per burst in follower neurones. Forskolin and IBMX increase levels of cardiac ganglion cyclic AMP, and IBMX also increases cyclic GMP levels in this tissue. Amines, forskolin and IBMX have direct effects on follower neurones pharmacologically isolated from pacemaker cell input. Octopamine, forskolin and IBMX depolarize follower neurones, while dopamine hyperpolarizes these cells. Amines, forskolin and IBMX elicit burst-like potentials in follower neurones, and increase the size of evoked, unitary junction potentials recorded in cardiac muscle fibres. These pharmacological and biochemical data suggest that multiple, excitatory effects of biogenic amines on the Limulus cardiac ganglion are mediated by simultaneous increases in cyclic AMP at several loci within this neural network.

Response of the Norepinephrine System to Antidepressant Drugs

CNS Spectrums ◽  
2001 ◽  
Vol 6 (8) ◽  
pp. 679-688 ◽  
Author(s):  
Steven T. Szabo ◽  
Pierre Blier
Keyword(s):  
Biogenic Amines ◽  
Affective Disorders ◽  
Time Course ◽  
Antidepressant Drugs ◽  
Mechanisms Of Action ◽  
Locus Ceruleus ◽  
Therapeutic Action ◽  
Sensory Afferents ◽  
Cortical Areas ◽  
Norepinephrine System

ABSTRACTEnvironmental stimuli and drugs affect the norepinephrine (NE) system and may be linked to the manifestation and treatment of anxiety and affective disorders. The activity of locus ceruleus NE neurons in the brainstem can alter the function offorebrain structures associated with several psychiatric disorders. In particular, NE neurons send and receive projections from sensory afferents, limbic areas, and cortical areas implicated in higher-order brain malfunctions and the symptomatology of anxiety and affective disorders. In turn, anxiolytic and antidepressant drugs are able to offset perturbations of NE activity and forebrain structures with a time course congruent with their therapeutic action. All antide-pressants, even the agents selective for other biogenic amines or peptides, act on the NE system. In the present review, the effects of antidepressants on NE neurons are summarized and applied to the treatment of neuropsychiatric disorders, with emphasis placed on mechanisms of action.

Reversible effects of phenothiazines on frog gastric stimulation

1984 ◽  
Vol 247 (4) ◽  
pp. G366-G376
Author(s):  
N. Raphael ◽  
E. B. Ekblad ◽  
T. E. Machen
Keyword(s):  
Adenylate Cyclase ◽  
Time Course ◽  
Phosphodiesterase Inhibitor ◽  
Secretory Activity ◽  
Gastric Stimulation ◽  
Camp Content ◽  
Oxyntic Cell ◽  
Camp Generation ◽  
Stimulus Secretion Coupling

The calmodulin inhibitors trifluoperazine (TFP), chlorpromazine (CPZ), and promethazine (PZ) were tested for effects on stimulus-secretion coupling in in vitro bullfrog gastric mucosa. When added to histamine-stimulated tissues, the drugs caused H+ secretion to decrease and transepithelial resistance to increase over a 2-h time course. The potency sequence was TFP (IC50 = 40 microM) greater than CPZ (IC50 = 72 microM) congruent to PZ (IC50 = 72 microM). Anesthetics and other phenothiazines with weak anticalmodulin activity had no effect on secretory parameters. In the presence of histamine, further addition of isobutylmethylxanthine (IBMX, a phosphodiesterase inhibitor) plus dibutyryl cAMP (DBcAMP), IBMX alone, or forskolin (a specific activator of adenylate cyclase) to phenothiazine-inhibited tissues caused full resumption of secretory activity. If TFP (50 microM) was added before stimulation with histamine, the normal increases in tissue cAMP content (which occurs primarily in oxyntic cells), oxyntic cell apical membrane elaboration (morphometric analysis of electron micrographs), and H+ secretion were all blocked. Subsequent addition of IBMX or IBMX plus DBcAMP completely reversed the TFP effect. These results indicate that the histamine-sensitive adenylate cyclase may be the site of TFP inhibition and Ca2+-calmodulin regulation; since these drugs inhibited stimulation by DBcAMP plus IBMX, they may also be exerting additional effects distal to cAMP generation.

scholarly journals To stimulate or not to stimulate? A rapid systematic review of repetitive sensory stimulation for the upper-limb following stroke

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rachel C. Stockley ◽  
Kerry Hanna ◽  
Louise Connell
Keyword(s):  
Systematic Review ◽  
Upper Limb ◽  
Meta Analysis ◽  
Hand Function ◽  
Research Priorities ◽  
Sensory Stimulation ◽  
Treatment Session ◽  
Current Evidence ◽  
Serious Adverse Events ◽  
Repetitive Sensory Stimulation

Abstract Background Repetitive sensory stimulation (RSS) is a therapeutic approach which involves repeated electrical stimulation of the skin’s surface to improve function. This rapid systematic review aimed to describe the current evidence for repetitive sensory stimulation (RSS) in rehabilitation of the upper-limb for people who have had a stroke. Main text Methods: Relevant studies were identified in a systematic search of electronic databases and hand-searching in February 2020. The findings of included studies were synthesized to describe: the safety of RSS, in whom and when after stroke it has been used, the doses used and its effectiveness. Results Eight studies were included. No serious adverse events were reported. The majority of studies used RSS in participants with mild or moderate impairments and in the chronic stage after stroke. Four studies used RSS in a single treatment session, reporting significant improvements in strength and hand function. Findings from longitudinal studies showed few significant differences between control and experimental groups. Meta-analysis was not possible due to the heterogeneity of included studies. Conclusions This review suggests that there is insufficient evidence to support the use of RSS for the upper-limb after stroke in clinical practice. However, this review highlights several clear research priorities including establishing the mechanism and in whom RSS may work, its safety and optimal treatment parameters to improve function of the upper-limb after stroke.

Dexamethasone and 8-bromo-cyclic AMP depress the incorporation of [3H]thymidine into mouse condylar cartilage by different pathways

1986 ◽  
Vol 109 (2) ◽  
pp. 209-213 ◽  
Author(s):  
Z. Kraiem ◽  
G. Maor ◽  
M. Silbermann
Keyword(s):  
Cyclic Amp ◽  
Thymidine Incorporation ◽  
Phosphodiesterase Inhibitor ◽  
Inhibitory Effect ◽  
Significant Inhibition ◽  
Condylar Cartilage ◽  
Camp Analogue ◽  
Dose Dependent Fashion ◽  
Cartilage Cells ◽  
Dose Dependent

ABSTRACT We examined whether cyclic AMP (cAMP) affects the incorporation of [3H]thymidine into cartilage cells and, if so, whether this action could be related to the inhibitory effect of glucocorticoid hormones on the growth of ossifying cartilage. Incorporation of [3H]thymidine into trichloroacetic acid-precipitable material by mouse cartilage was measured concomitantly with the concentration of cAMP. Dexamethasone (1 μmol/l) significantly (P < 0·05) depressed the incorporation of [3H]thymidine. The cAMP analogue 8-bromo-cAMP (0·01–1 mmol/l) also depressed the incorporation of the radionucleotide in a dose-dependent fashion. When various concentrations of 8-bromo-cAMP were added with dexamethasone (1 μmol/l), no apparent changes took place compared with the effect of dexamethasone alone. The phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (0·2-1 mmol/l) elicited an inhibitory effect on [3H]thymidine incorporation and a stimulatory influence on cartilage cAMP concentrations. Dexamethasone, at doses (0·01–1 μmol/l) causing significant inhibition of [3H]thymidine incorporation, failed to increase cartilage levels of cAMP. It seems, therefore, that the depressive effect of dexamethasone on [3H]thymidine incorporation in condylar cartilage is not mediated through an increase of cAMP in the tissue. J. Endocr. (1986) 109, 209–213

scholarly journals Dynamics of visual perceptual processing in freely behaving mice

2020 ◽  
Author(s):  
Wen-Kai You ◽  
Shreesh P. Mysore
Keyword(s):  
Visual Perception ◽  
Time Course ◽  
Neural Circuit ◽  
Short Term Memory ◽  
Human Perception ◽  
Orientation Discrimination ◽  
Sensory Encoding ◽  
Stimulus Features ◽  
Two Stages ◽  
Speed Accuracy

ABSTRACTMice are being used increasing commonly to study visual behaviors, but the time-course of their perceptual dynamics is unclear. Here, using conditional accuracy analysis, a powerful method used to analyze human perception, and drift diffusion modeling, we investigated the dynamics and limits of mouse visual perception with a 2AFC orientation discrimination task. We found that it includes two stages – a short, sensory encoding stage lasting ∼300 ms, which involves the speed-accuracy tradeoff, and a longer visual short-term memory-dependent (VSTM) stage lasting ∼1700 ms. Manipulating stimulus features or adding a foil affected the sensory encoding stage, and manipulating stimulus duration altered the VSTM stage, of mouse perception. Additionally, mice discriminated targets as brief as 100 ms, and exhibited classic psychometric curves in a visual search task. Our results reveal surprising parallels between mouse and human visual perceptual processes, and provide a quantitative scaffold for exploring neural circuit mechanisms of visual perception.

scholarly journals Effects of simultaneous use of methyl jasmonate with other plant hormones on the level of anthocyanins and biogenic amines in seedlings of common buckwheat (Fagopyrum esculentum Moench)

2013 ◽  
Vol 66 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Marcin Horbowicz ◽  
Ryszard Kosson ◽  
Marian Saniewski ◽  
Joanna Mitrus ◽  
Danuta Koczkodaj
Keyword(s):  
Methyl Jasmonate ◽  
Biogenic Amines ◽  
Anthocyanin Synthesis ◽  
Anthocyanin Content ◽  
Common Buckwheat ◽  
High Accumulation ◽  
Simultaneous Application ◽  
Combined Use ◽  
Fagopyrum Esculentum Moench ◽  
The Impact

The aim of the study was to assess the impact of auxin (IAA), gibberellin (GA<sub>3</sub>) and cytokinin (kinetin), used solely and in combination with methyl jasmonate (MJ), on the accumulation of anthocyanins and biogenic amines in hypocotyls and cotyledons of common buckwheat (<em>Fagopyru</em><em>m esculentum </em>Moench) seedlings. The obtained results indicate that accumulation of anthocyanins in buckwheat seedlings was dependent on the concentration of the phytohormone applied and the tissue studied. The combined use of MJ and IAA, GA<sub>3</sub>  or kinetin partly reversed the effect of strong inhibition of anthocyanin synthesis by MJ. IAA used solely decreased the level of anthocyanins in de-etiolated buckwheat cotyledons. IAA also caused a reduction of putrescine content, both in hypocotyls and cotyledons of buckwheat seedlings. MJ used alone caused high accumulation of 2-phenylethylamine (PEA) in buckwheat cotyledons and hypocotyls. The simultaneous application of MJ and IAA, GA<sub>3</sub>  or kinetin also stimulated PEA synthesis in buckwheat tissues, however this effect was significantly lower compared to the use of MJ only. A reverse significant correlation between PEA and anthocyanin contents occurred in buckwheat hypocotyls, but not in cotyledons. It was suggested that the deficiency of L-phenylalanine, a substrate for synthesis of 2-phenylethylamine, may be partly responsible for the decline in anthocyanin content in buckwheat hypocotyls under the influence of MJ.

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