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E Arilla - One of the best experts on this subject based on the ideXlab platform.
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histamine h1 receptors modulate somatostatin receptors coupled to the inhibition of adenylyl cyclase in the rat Frontoparietal Cortex
Peptides, 1997Co-Authors: Lilian Puebla, Aurelio Ocana Fuentes, E ArillaAbstract:PUEBLA, L., A. OCANA AND E. ARILLA. Histamine H1-receptors modulate somatostatin receptors coupled to the inhibition of adenylyl cyclase in the rat Frontoparietal Cortex.Peptides 18(10) 1569 -1576, 1997.—Since exogenous histamine has been previously shown to increase the somatostatin (SS) receptor-effector system in the rat Frontoparietal Cortex and both histamine H 1-receptor agonists and SS modulate higher nervous activity and have anticonvulsive properties, it was of interest to determine the participation of the H1-histaminergic system in this response. The intracerebroventricular (i.c.v.) administration of the specific histamine H1-receptor agonist 2-pyridylethylamine (PEA) (10 mg) to rats 2 h before decapitation increased the number of SS receptors (599 6 40 vs 401 6 31 femtomoles/mg protein, p, 0.01) and decreased their apparent affinity for SS (0.41 6 0.03 vs 0.26 6 0.02 nM, p , 0.01) in rat Frontoparietal cortical membranes. No significant differences were seen for the basal and forskolin (FK)-stimulated adenylyl cyclase (AC) activities in the Frontoparietal Cortex of PEA-treated rats when compared to the control group. In the PEA group, however, the capacity of SS (10 24 M) to inhibit basal and FK (10 25 M)-stimulated AC activity in Frontoparietal cortical membranes was significantly higher than in the control group (34 6 1% vs 20 6 2%, p , 0.001). The ability of low concentrations of the stable GTP analogue 59-guanylylimidodiphosphate (Gpp(NH)p) to inhibit FK-stimulated AC activity in Frontoparietal cortical membranes was similar in the PEA-treated and control animals. These results suggest that the increased SS-mediated inhibition of AC activity in the Frontoparietal Cortex of PEA-treated rats may be due to the increase of the number of SS receptors induced by PEA. Pretreatment with the H1-receptor antagonist mepyramine (30 mg/kg, intraperitoneally (IP) prevented the PEA-induced changes in SS binding and SS-mediated inhibition of AC activity. Mepyramine (30 mg/kg, IP) alone had no observable effect on the somatostatinergic system. The in vitro addition of PEA or mepyramine to Frontoparietal cortical membranes obtained from untreated rats did not affect the SS binding parameters. Altogether, these results suggest that the H 1-histaminergic system modulates the somatostatinergic system in the rat Frontoparietal Cortex. © 1997 Elsevier Science Inc.
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effect of somatostatin on the mass accumulation of inositol 1 4 5 trisphosphate in rat hypothalamus striatum Frontoparietal Cortex and hippocampus
Neuroscience Letters, 1995Co-Authors: G Munozacedo, Rosa Maria Izquierdoclaros, J A Sanchezalonso, N Del Hoyo, M A Perezalbarsanz, E ArillaAbstract:Abstract Somatostatin-14 (SS) significantly increased inositol-1,4,5-triphosphate (IP 3 ) accumulation in rat hypothalamic, striatal, Frontoparietal cortical and hippocampal slices. However, this stimulation of IP 3 accumulation by SS was highest in the Frontoparietal Cortex and hippocampus. The effect was already significant with 0.01 μM in the Frontoparietal Cortex ( P P 3 accumulation in all brain areas studied. This effect was maximal at 15 s of incubation and decreased subsequently. At 60 s incubation, levels were still elevated in Frontoparietal Cortex and hippocampus but had returned to basal values in hypothalamus and striatum. Somatostatin-28 (SS-28) and the SS analogues, d -Trp 8 - d -Cys 14 and SMS 201–995, also significantly stimulated IP 3 accumulation although the effect of SMS 201–995 was greater than that of SS in the striatum in comparison with controls ( P P 3 , which may initiate intracellular processes responsible for some biological SS effects.
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exogenous histamine increases the somatostatin receptor effector system in the rat Frontoparietal Cortex
European Journal of Pharmacology, 1995Co-Authors: Lilian Puebla, E ArillaAbstract:The present study examined the effects of histamine on somatostatin-like immunoreactivity levels, binding of 125I-[Tyr11]somatostatin to its specific receptors, somatostatin inhibition of basal and forskolin-stimulated adenylyl cyclase activity and inhibitory guanine-nucleotide binding protein (Gi) function in the rat Frontoparietal Cortex. An intracerebroventricular (i.c.v.) dose of 10 micrograms or 1 microgram of histamine induced an increase in the number of specific 125I-[Tyr11]somatostatin receptors (590 +/- 22 vs 358 +/- 12 fmol/mg protein, P < 0.001 and 455 +/- 20 vs. 342 +/- 21 fmol/mg protein, P < 0.01, respectively) together with a decrease in their apparent affinity (0.76 +/- 0.04 vs 0.39 +/- 0.02 nM, P < 0.001 and 0.60 +/- 0.03 vs 0.39 +/- 0.05 nM, P < 0.01, respectively) in rat Frontoparietal Cortex membranes. This increase in tracer binding was not due to a direct effect of histamine on the somatostatin receptors since no change in binding was produced when histamine was added directly to the incubation medium. No significant differences were seen for either the basal or forskolin-stimulated adenylyl cyclase activity in Frontoparietal Cortex membranes of histamine-treated rats as compared with the control group. In rats treated with 10 micrograms of histamine, however, somatostatin caused a significantly greater inhibition of basal and forskolin-stimulated adenylyl cyclase activity as compared to the control group (33 +/- 4% vs 19 +/- 1% inhibition, P < 0.05 and 31 +/- 1% vs 21 +/- 3% inhibition, P < 0.05, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
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effect of phenylephrine and prazosin on the somatostatinergic system in the rat Frontoparietal Cortex
Peptides, 1995Co-Authors: Susana Lopezsanudo, E Rodriguezmartin, Angela Martinespinosa, E ArillaAbstract:Somatostatin (SS) and noradrenaline (NA) are distributed in the rat cerebral Cortex, and seizure activity is one of the aspects of behavior affected by both neurotransmitters. Due to the possible interaction between both neurotransmitter systems, we studied whether phenylphrine, an alpha 1-adrenoceptor agonist, and prazosin, an alpha 1-adrenoceptor antagonist, can modulate SS-like immunoreactivity (SS-LI) levels, binding of [125I][Tyr11]SS to its specific receptors, the ability of SS to inhibit adenylate cyclase (AC) activity, and the guanine nucleotide binding regulatory protein G, and G., in the Sprague-Dawley rat Frontoparietal Cortex. An IP dose of 2 or 4 mg/kg of phenylephrine injected 7 h before decapitation decreased the number of SS receptors and increased the apparent affinity in Frontoparietal Cortex membranes. An IP dose of 20 or 25 mg/kg of prazosin administered 8 h before decapitation increased the number of SS receptors and decreased their apparent affinity. The administration of prazosin before the phenylephrine injection prevented the phenylephrine-induced changes in SS binding. The addition of phenylephrine and/or prazosin 10(-5) M to the incubation medium changed neither the number nor the affinity of the SS receptors in the Frontoparietal Cortex membranes. Phenylephrine or prazosin affected neither SS-LI content nor the basal or forskolin (FK)-stimulated AC activities in the Frontoparietal Cortex. In addition, SS caused an equal inhibition of AC activity in Frontoparietal Cortex membranes of phenylephrine-and prazosintreated rats compared with the respective control group. Finally, phenylephrine and prazosin did not vary the pertussis toxin (PTX)-catalyzed ADP ribosylation of Gi- and/or Go-proteins. These results suggest that the above-mentioned changes are related to the phenylephrine activation of alpha 1-adrenoceptors or to the blocking of these receptors by prazosin. In addition, these data provide further support for a functional interrelationship between the alpha 1-adrenergic and somatostatinergic systems in the rat Frontoparietal Cortex.
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somatostatin receptors coupled to the inhibition of adenylyl cyclase in the rat Frontoparietal Cortex are modulated by α2 adrenoceptors
Molecular Brain Research, 1994Co-Authors: Susana Lopezsanudo, E ArillaAbstract:Abstract The administration of an α 2 -adrenoceptor agonist, clonidine, increased number of somatostatin (SS) receptors and the affinity constant in Frontoparietal Cortex membranes. In addition, in the clonidine group, the capacity of SS to inhibit basal and forskolin (FK)-stimulated adenylyl cyclase (AC) activity in the Frontoparietal Cortex was significantly higher than in the control group. Pretreatment with the α 2 -adrenoceptor antagonist yohimbine prevented the clonidine-induced changes in SS binding and SS-inhibited AC activity. Yohimbine alone had an opposite effect from clonidine. These experiments provide further evidence that the α 2 -adrenergic system modulates the rat Frontoparietal Cortex somatostatinergic system.
Jon H Kaas - One of the best experts on this subject based on the ideXlab platform.
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microstimulation and architectonics of Frontoparietal Cortex in common marmosets callithrix jacchus
The Journal of Comparative Neurology, 2008Co-Authors: Mark J Burish, Iwona Stepniewska, Jon H KaasAbstract:We investigated the organization of Frontoparietal Cortex in the common marmoset (Callithrix jacchus) by using intracortical microstimulation and an architectonic analysis. Primary motor Cortex (M1) was identified as an area that evoked visible movements at low levels of electric current and had a full body representation of the contralateral musculature. Primary motor Cortex represented the contralateral body from hindlimb to face in a mediolateral sequence, with individual movements such as jaw and wrist represented in multiple nearby locations. Primary motor Cortex was coextensive with an agranular area of Cortex marked by a distinct layer V of large pyramidal cells that gradually decreased in size toward the rostral portion of the area and was more homogenous in appearance than other New World primates. In addition to M1, stimulation also evoked movements from several other areas of Frontoparietal Cortex. Caudal to primary motor Cortex, area 3a was identified as a thin strip of Cortex where movements could be evoked at thresholds similar to those in M1. Rostral to primary motor Cortex, supplementary motor Cortex and premotor areas responded to higher stimulation currents and had smaller layer V pyramidal cells. Other areas evoking movements included primary somatosensory Cortex (area 3b), two lateral somatosensory areas (areas PV and S2), and a caudal somatosensory area. Our results suggest that Frontoparietal Cortex in marmosets is organized in a similar fashion to that of other New World primates. J. Comp. Neurol. 507:1151–1168, 2008. © 2008 Wiley-Liss, Inc.
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the organization of Frontoparietal Cortex in the tree shrew tupaia belangeri ii connectional evidence for a frontal posterior parietal network
The Journal of Comparative Neurology, 2007Co-Authors: Michael S Remple, Iwona Stepniewska, Jamie L Reed, David C Lyon, Jon H KaasAbstract:Tree shrews are small squirrel-like mammals that are the closest living relative to primates available for detailed neurobiological study. In a recent study (Remple et al. [2006] J. Comp. Neurol. 497:133-154), we provided anatomical and electrophysiological evidence that the Frontoparietal Cortex of tree shrews has two motor fields (M1 and M2) and five somatosensory fields (3a, 3b, S2, somatosensory caudal area [SC], and parietal ventral area [PV]). In the present study, we injected anatomical tracers into M1, M2, 3a, 3b, SC, and posterior parietal Cortex to establish the ipsilateral cortical connections of these areas. The results provide evidence for a number of new cortical areas including medial motor and somatosensory areas (MMA and MSA), three posterior parietal areas (PPd, PPv, and PPc), and an area ventral to temporal inferior Cortex (TIV). Ml receives topographic projections from M2, MMA, 3a, and PPv, and nontopographic connections from the temporal anterior and dorsal areas (TA and TD), PPc, TIV, and MSA. The connections of M2 are similar to those of M1, except that M2 receives denser projections from TIV, PPc, and dorsal frontal Cortex and sparser input from M1. Areas 3a, 3b, and SC receive dense topographic projections from each other, S2, and PV and sparser connections from PPd and PPv. Area 3a receives additional input from posterior parietal and temporal regions and from M1 and MMA. Overall, the Frontoparietal connections of tree shrew Cortex are most similar to those of prosimian primates and quite different from those of more distant relatives such as rats.
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organization of Frontoparietal Cortex in the tree shrew tupaia belangeri i architecture microelectrode maps and corticospinal connections
The Journal of Comparative Neurology, 2006Co-Authors: Michael S Remple, Iwona Stepniewska, Jamie L Reed, Jon H KaasAbstract:Despite extensive investigation of the motor Cortex of primates, little is known about the organization of motor Cortex in tree shrews, one of their closest living relatives. We investigated the organization of Frontoparietal Cortex in Belanger's tree shrews (Tupaia belangeri) by using intracortical microstimulation (ICMS), corticospinal tracing, and detailed histological analysis. The results provide evidence for the subdivision of tree shrew Frontoparietal Cortex into seven distinct areas (five are newly identified), including two motor fields (M1 and M2) and five somatosensory fields (3a, 3b, S2, PV, and SC). The types of movements evoked in M1 and M2 were similar, but M2 required higher currents to elicit movements and had few connections to the cervical spinal cord and distinctive cyto- and immunoarchitecture. The borders between M1 and the anterior somatosensory regions (3a and 3b) were identified primarily from histological analysis, because thresholds were similar between these regions, and differences in corticospinal neuron distribution were subtle. The caudal (SC) and lateral (S2 and PV) somatosensory fields were identified based on differences in architecture and distribution of corticospinal neurons. Myelin-dense modules were identified in lateral Cortex, in the expected location of the oral, forelimb, and hindlimb representations of S2, and possibly PV. Evidence for a complex primate-like array of motor fields is lacking in tree shrews, but their motor Cortex shares a number of basic features with that of primates, which are not found in more distantly related species, such as rats.
Lilian Puebla - One of the best experts on this subject based on the ideXlab platform.
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modulation of somatostatin receptors somatostatin content and gi proteins by substance p in the rat Frontoparietal Cortex and hippocampus
Journal of Neurochemistry, 2002Co-Authors: Lilian Puebla, Eduardo ArillaferreiroAbstract:Substance P (SP) and somatostatin (SRIF) are widely spread throughout the CNS where they play a role as neurotransmitters and/or neuromodulators. A colocalization of both neuropeptides has been demonstrated in several rat brain areas and SP receptors have been detected in rat cortical and hippocampal somatostatinergic cells. The present study was thus undertaken to determine whether SP could modulate SRIF signaling pathways in the rat Frontoparietal Cortex and hippocampus. A single intraperitoneal injection of SP (50, 250 or 500 µg/kg) induced an increase in the density of SRIF receptors in membranes from the rat Frontoparietal Cortex at 24 h of its administration, with no change in the hippocampus. The functionality of the SRIF receptors was next investigated. Western blot analysis of Gi proteins demonstrated a significant decrease in Giα1 levels in Frontoparietal cortical membranes from rats treated acutely (24 h) with 250 µg/kg of SP, which correlated with a decrease in functional Gi activity, as assessed by use of the non-hydrolyzable GTP analog 5′-guanylylimidodiphosphate. SRIF-mediated inhibition of basal or forskolin-stimulated adenylyl cyclase activity was also significantly lower in the Frontoparietal Cortex of the SP-treated group, with no alterations in the catalytic subunit of the enzyme. SRIF-like immunoreactivity content was increased in the Frontoparietal Cortex after acute (24 h) SP administration (250 or 500 µg/kg) as well as in the hippocampus in response to 7 days of SP (250 µg/kg) administration. All these SP-mediated effects were prevented by pretreatment with the NK1 receptor antagonist RP-67580. Although the physiologic significance of these results are unknown, the increase in SRIF receptor density together with the desensitization of the SRIF inhibitory signaling pathway might be a mechanism to potentiate the stimulatory pathway of SRIF, inducing a preferential coupling of the receptors to PLC.
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Involvement of presynaptic histamine H3 receptors in the modulation of somatostatin binding and its effects on adenylyl cyclase activity in the rat Frontoparietal Cortex.
Journal of neurochemistry, 2002Co-Authors: Lilian Puebla, Eduardo ArillaAbstract:Thioperamide (2 mg/kg, i.p.), a histamine H 3 -receptor antagonist, increased the number of somatostatin (SS) receptors, with no change in the affinity constant, in the rat Frontoparietal Cortex. This effect was prevented by treatment with (R)-α-methylhistamine (3.2 mg/kg, i.p.), a histamine H 3 -receptor agonist. Thioperamide also induced an increase in SS binding in rats pretreated with mepyramine, a histamine H 1 -receptor antagonist, or cimetidine, a histamine H 2 -receptor antagonist. Pretreatment with mepyramine plus cimetidine administered simultaneously antagonized the thioperamide effect on SS binding. The increase in the number of SS receptors was accompanied by a greater SS-mediated inhibition of basal and forskolin-stimulated adenylyl cyclase (AC) activity in Frontoparietal cortical membranes in the thioperamide group. Furthermore, the functional activity of the guanine nucleotide-binding inhibitory protein (G i protein) was not altered by thioperamide or (R)-α-methylhistamine administration in Frontoparietal cortical membranes. In rats treated with mepyramine plus thioperamide or cimetidine plus thioperamide, the increase in the number of SS receptors was also accompanied by an increased SS inhibition of AC activity. Thioperamide induced a significant increase in SS-like immunoreactivity content in the Frontoparietal Cortex. Altogether, these results suggest that Frontoparietal cortical histamine may play, at least in part, a role in the regulation of the somatostatinergic system.
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histamine h1 receptors modulate somatostatin receptors coupled to the inhibition of adenylyl cyclase in the rat Frontoparietal Cortex
Peptides, 1997Co-Authors: Lilian Puebla, Aurelio Ocana Fuentes, E ArillaAbstract:PUEBLA, L., A. OCANA AND E. ARILLA. Histamine H1-receptors modulate somatostatin receptors coupled to the inhibition of adenylyl cyclase in the rat Frontoparietal Cortex.Peptides 18(10) 1569 -1576, 1997.—Since exogenous histamine has been previously shown to increase the somatostatin (SS) receptor-effector system in the rat Frontoparietal Cortex and both histamine H 1-receptor agonists and SS modulate higher nervous activity and have anticonvulsive properties, it was of interest to determine the participation of the H1-histaminergic system in this response. The intracerebroventricular (i.c.v.) administration of the specific histamine H1-receptor agonist 2-pyridylethylamine (PEA) (10 mg) to rats 2 h before decapitation increased the number of SS receptors (599 6 40 vs 401 6 31 femtomoles/mg protein, p, 0.01) and decreased their apparent affinity for SS (0.41 6 0.03 vs 0.26 6 0.02 nM, p , 0.01) in rat Frontoparietal cortical membranes. No significant differences were seen for the basal and forskolin (FK)-stimulated adenylyl cyclase (AC) activities in the Frontoparietal Cortex of PEA-treated rats when compared to the control group. In the PEA group, however, the capacity of SS (10 24 M) to inhibit basal and FK (10 25 M)-stimulated AC activity in Frontoparietal cortical membranes was significantly higher than in the control group (34 6 1% vs 20 6 2%, p , 0.001). The ability of low concentrations of the stable GTP analogue 59-guanylylimidodiphosphate (Gpp(NH)p) to inhibit FK-stimulated AC activity in Frontoparietal cortical membranes was similar in the PEA-treated and control animals. These results suggest that the increased SS-mediated inhibition of AC activity in the Frontoparietal Cortex of PEA-treated rats may be due to the increase of the number of SS receptors induced by PEA. Pretreatment with the H1-receptor antagonist mepyramine (30 mg/kg, intraperitoneally (IP) prevented the PEA-induced changes in SS binding and SS-mediated inhibition of AC activity. Mepyramine (30 mg/kg, IP) alone had no observable effect on the somatostatinergic system. The in vitro addition of PEA or mepyramine to Frontoparietal cortical membranes obtained from untreated rats did not affect the SS binding parameters. Altogether, these results suggest that the H 1-histaminergic system modulates the somatostatinergic system in the rat Frontoparietal Cortex. © 1997 Elsevier Science Inc.
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PII S0196-9781(97)00224-6 Histamine H1-Receptors Modulate Somatostatin Receptors Coupled to the Inhibition of Adenylyl Cyclase in the Rat Frontoparietal Cortex
1997Co-Authors: Lilian Puebla, Aurelio Ocan, A Fuentes, Eduardo ArillaAbstract:adenylyl cyclase in the rat Frontoparietal Cortex. Peptides 18(10) 1569–1576, 1997.—Since exogenous histamine has been previously shown to increase the somatostatin (SS) receptor-effector system in the rat Frontoparietal Cortex and both histamine H1-receptor agonists and SS modulate higher nervous activity and have anticonvulsive properties, it was of interest to determine the participation of the H1-histaminergic system in this response. The intracerebroventricular (i.c.v.) administration of the specific histamine H1-receptor agonist 2-pyridylethylamine (PEA) (10 mg) to rats 2 h before decapitation increased the number of SS receptors (599 6 40 vs 401 6 31 femtomoles/mg protein, p, 0.01) and decreased their apparent affinity for SS (0.41 6 0.03 vs 0.26 6 0.02 nM, p, 0.01) in rat Frontoparietal cortical membranes. No significant differences were seen for the basal and forskolin (FK)-stimulated adenylyl cyclase (AC) activities in the Frontoparietal Cortex of PEA-treated rats when compared to the control group. In the PEA group, however, the capacity of SS (1024 M) to inhibit basal and FK (1025 M)-stimulated AC activity in Frontoparietal cortical membranes was significantly higher than in the control group (34 6 1 % vs 20 6 2%, p, 0.001). The ability of low concentrations of the stable GTP analogue 59-guanylylimidodiphosphate [Gpp(NH)p] to inhibit FK-stimulated AC activity in Frontoparietal cortical membranes was similar in the PEA-treated and control animals. These results suggest that the increased SS-mediated inhibition of AC activity in the Frontoparietal Cortex of PEA-treated rats may be due to the increase of the number of SS receptors induced by PEA. Pretreatment with the H1-receptor antagonist mepyramine (30 mg/kg, intraperitoneally (IP) prevented the PEA-induced changes in SS binding and SS-mediated inhibitio
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Effect of Dimaprit and Cimetidine on the Somatostatinergic System in the Rat Frontoparietal Cortex
Neuropsychopharmacology, 1996Co-Authors: Lilian Puebla, Eduardo ArillaAbstract:A recent study carried out by this laboratory demonstrated that exogenous histamine increases the somatostatin (SS) receptor/effector system in the rat Frontoparietal Cortex (Puebla and Arilla, 1995). In the present study we examined the participation of the H_2-histaminergic system in this modulation by use of the H_2-receptor agonist and antagonist dimaprit and cimetidine, respectively. Dimaprit administration [20 μg/rat, intracerebroventricularly (ICV)] to rats 2 hours before decapitation increased the number of SS receptors in the Frontoparietal Cortex without changing the affinity constant. Pretreatment with cimetidine (20 μg/rat, ICV) prevented the dimaprit-induced changes in SS binding in the Frontoparietal Cortex, whereas cimetidine alone (20 μg/rat, ICV) had no observable effect on this parameter. The in vitro addition of dimaprit or cimetidine to Frontoparietal Cortex membranes from untreated rats did not markedly affect the SS binding characteristics. Somatostatin caused a significantly higher inhibition of basal and forskolin (FK)-stimulated adenylyl cyclase (AC) activity in Frontoparietal Cortex membranes from dimaprit-treated rats than in controls, an effect that was prevented by pretreatment with cimetidine. No significant differences, however, were detected for the basal or FK-stimulated AC enzyme activity in the control, dimaprit-, and/or cimetidine-treated groups, which suggests no impairment of the AC catalytic subunit. In addition, the functional activity of the guanine nucleotide-binding inhibitory protein G_i, as measured by the capacity of the stable GTP analogue 5′-guanylylimidodiphosphate [Gpp(NH)p] to inhibit FK-stimulated AC activity, was not altered by dimaprit. Thus, the increased SS-mediated inhibition of AC activity observed in the dimaprit-treated rats may be caused by the increase in the number of SS receptors. Neither dimaprit nor cimetidine affected somatostatinlike immunoreactivity (SSLI) content. The present results, together with the fact that SS and histamine have been shown to influence locomotor activity and nociception in a similar manner, suggest that some of the neurotransmitter effects of SS may be modulated by histamine via H_2-histaminergic receptors.
Eduardo Arillaferreiro - One of the best experts on this subject based on the ideXlab platform.
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differential effects of ethanol ingestion on somatostatin content somatostatin receptors and adenylyl cyclase activity in the Frontoparietal Cortex of virgin and parturient rats
Life Sciences, 2005Co-Authors: Vicente Barrios, Maria Del Carmen Boyanoadanez, L Pueblajimenez, Manuel Sanz, Leandro Sorianoguillen, Eduardo ArillaferreiroAbstract:Chronic ethanol ingestion decreases the number of somatostatin (SRIF) receptors in the rat Frontoparietal Cortex and female sex hormones modulate the effects of ethanol in the brain. Therefore, we investigated the differential effects of ethanol consumption on the SRIFergic system in the Frontoparietal Cortex of virgin and parturient rats given ethanol in their drinking water before and during gestation. In parturient rats, ethanol consumption decreased the density of SRIF receptors (25%, pb0.01 vs control parturient group) whereas the SRIF-like immunoreactivity (SRIF-LI) content was increased (140%, pb0.01). In virgin rats, ethanol ingestion decreased the density of SRIF receptors (42%, pb0.01) more than in alcoholic parturient rats. SRIF-LI levels were unaffected. The inhibitory effect of SRIF on basal and forskolin-stimulated adenylyl cyclase was significantly lower in alcoholic virgin rats as compared to alcoholic parturient rats. No differences in the levels of the G inhibitory (Gi) a1 and Gia2 proteins were observed among the experimental groups. These results suggest that gestation may confer partial resistance to the ethanol-induced effect on the SRIFergic system.
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modulation of somatostatin receptors somatostatin content and gi proteins by substance p in the rat Frontoparietal Cortex and hippocampus
Journal of Neurochemistry, 2002Co-Authors: Lilian Puebla, Eduardo ArillaferreiroAbstract:Substance P (SP) and somatostatin (SRIF) are widely spread throughout the CNS where they play a role as neurotransmitters and/or neuromodulators. A colocalization of both neuropeptides has been demonstrated in several rat brain areas and SP receptors have been detected in rat cortical and hippocampal somatostatinergic cells. The present study was thus undertaken to determine whether SP could modulate SRIF signaling pathways in the rat Frontoparietal Cortex and hippocampus. A single intraperitoneal injection of SP (50, 250 or 500 µg/kg) induced an increase in the density of SRIF receptors in membranes from the rat Frontoparietal Cortex at 24 h of its administration, with no change in the hippocampus. The functionality of the SRIF receptors was next investigated. Western blot analysis of Gi proteins demonstrated a significant decrease in Giα1 levels in Frontoparietal cortical membranes from rats treated acutely (24 h) with 250 µg/kg of SP, which correlated with a decrease in functional Gi activity, as assessed by use of the non-hydrolyzable GTP analog 5′-guanylylimidodiphosphate. SRIF-mediated inhibition of basal or forskolin-stimulated adenylyl cyclase activity was also significantly lower in the Frontoparietal Cortex of the SP-treated group, with no alterations in the catalytic subunit of the enzyme. SRIF-like immunoreactivity content was increased in the Frontoparietal Cortex after acute (24 h) SP administration (250 or 500 µg/kg) as well as in the hippocampus in response to 7 days of SP (250 µg/kg) administration. All these SP-mediated effects were prevented by pretreatment with the NK1 receptor antagonist RP-67580. Although the physiologic significance of these results are unknown, the increase in SRIF receptor density together with the desensitization of the SRIF inhibitory signaling pathway might be a mechanism to potentiate the stimulatory pathway of SRIF, inducing a preferential coupling of the receptors to PLC.
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effects of subchronic and chronic melatonin treatment on somatostatin binding and its effects on adenylyl cyclase activity in the rat Frontoparietal Cortex
Journal of Pineal Research, 2002Co-Authors: Rosa Maria Izquierdoclaros, Maria Del Carmen Boyanoadanez, Eduardo ArillaferreiroAbstract:Melatonin and somatostatin are known to exert similar effects on locomotor activity. We have previously demonstrated that acute melatonin treatment regulates somatostatin receptor function in the rat Frontoparietal Cortex. However, the effects of subchronic and chronic melatonin treatment on the somatostatin receptor-G protein-adenylyl cyclase system in the rat Frontoparietal Cortex are unknown. Melatonin was administered subcutaneously at a daily dose of 25 microg/kg for 4 days, 1 wk or 2 wk. Twenty-four hours after the last injection, the animals were sacrificed. Melatonin did not alter the somatostatin-like immunoreactivity content in the Frontoparietal Cortex from control and melatonin-treated rats during any of the previously indicated periods. Four days of melatonin administration induced both an increase in the number of [(125)I]-Tyr11-somatostatin receptors and a decrease in the affinity of somatostatin for its receptors in Frontoparietal cortical membranes. The increased number of somatostatin receptors in the melatonin-treated rats was associated with an increased capacity of somatostatin to inhibit basal and forskolin-stimulated adenylyl cyclase activity. Melatonin administration for 4 days induced a higher adenylyl cyclase activity both under basal conditions and after direct stimulation of the enzyme with forskolin. No significant differences were observed in the function of Gi proteins in the 4-day melatonin-treated rats. Western blot analyses showed that the 4-day melatonin treatment reduced Gialpha(2) levels, without altering the amount of Gialpha(1). These melatonin-induced changes reverted to control values after 7 or 14 days of treatment. Altogether, the present findings suggest that subchronic melatonin treatment modulates the somatostatin receptor/effector system in the rat Frontoparietal Cortex.
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acute modulation of somatostatin receptor function by melatonin in the rat Frontoparietal Cortex
Journal of Pineal Research, 2001Co-Authors: Rosa Maria Izquierdoclaros, Maria Del Carmen Boyanoadanez, Guadalupe Torrecillas, Manuel Rodriguezpuyol, Eduardo ArillaferreiroAbstract:Since melatonin (N-acetyl-5-methoxytryptamine) decreases locomotor activity and rearing and increases grooming behavior in a similar manner as somatostatin (SRIF), we examined if melatonin could induce these changes through somatostatinergic neurotransmission in the rat Frontoparietal Cortex. Male Wistar rats (200-250 g) received a single injection of melatonin (25 microg/kg per day) subcutaneously (s.c.) and were sacrificed 5 hr later. Melatonin treatment increased the number of 125I-Tyr11-SRIF receptors in Frontoparietal cortical membranes without any changes in the dissociation constant (Kd). The capacity of SRIF to inhibit basal and forskolin (FK)-stimulated adenylyl cyclase (AC) activity was increased in melatonin-treated rats as compared to the control animals. Melatonin administration also induced a lower AC activity, both under basal conditions and after stimulation of the enzyme via stimulatory guanine nucleotide-binding proteins (Gs), or directly with FK. Functional inhibitory guanine nucleotide-binding protein (Gi) activity was increased in Frontoparietal cortical membranes from melatonin-treated rats when compared to controls. Western blot analyzes showed that melatonin administration did not alter the amount of the Gialpha1, or Gialpha3 subunits, but reduced Gialpha2 levels in Frontoparietal cortical membranes. No significant changes in SRIF-like immunoreactivity content and SRIF mRNA levels were detected in this brain area after melatonin treatment. Administration of the melatonin receptor antagonist luzindole (10 mg/kg, s.c.) 30 min before melatonin injection did not change the melatonin-induced effects on the SRIF receptor effector system. In conclusion, the present results show that acute melatonin administration increases the activity of the SRIF receptor effector system and decreases Gialpha2 levels in the rat Frontoparietal Cortex. In addition, the coupling of Gs to AC is disturbed by melatonin.
Alfonso Caramazza - One of the best experts on this subject based on the ideXlab platform.
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distinct roles of temporal and Frontoparietal Cortex in representing actions across vision and language
Nature Communications, 2019Co-Authors: Moritz F Wurm, Alfonso CaramazzaAbstract:Both temporal and Frontoparietal brain areas are associated with the representation of knowledge about the world, in particular about actions. However, what these brain regions represent and precisely how they differ remains unknown. Here, we reveal distinct functional profiles of lateral temporal and Frontoparietal Cortex using fMRI-based MVPA. Frontoparietal areas encode representations of observed actions and corresponding written sentences in an overlapping way, but these representations do not generalize across stimulus type. By contrast, only left lateral posterior temporal Cortex (LPTC) encodes action representations that generalize across observed action scenes and written descriptions. The representational organization of stimulus-general action information in LPTC can be predicted from models that describe basic agent-patient relations (object- and person-directedness) and the general semantic similarity between actions. Our results suggest that LPTC encodes general, conceptual aspects of actions whereas Frontoparietal representations appear to be tied to specific stimulus types. Temporal and Frontoparietal brain areas both encode representations of actions, but whether they do so in different ways is unclear. Here, the authors show that only lateral posterior temporal Cortex (LPTC) encodes representations that generalize across directly observed action scenes and written descriptions.
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distinct profiles of temporal and Frontoparietal Cortex in representing actions across vision and language
bioRxiv, 2018Co-Authors: Moritz F Wurm, Alfonso CaramazzaAbstract:Abstract Both temporal and Frontoparietal brain areas are associated with the representation of knowledge about the world, in particular about actions. However, what these brain regions represent and precisely how they differ remains unknown. Here, we reveal fundamentally distinct functional profiles of lateral temporal and Frontoparietal Cortex: Using fMRI-based MVPA we found that Frontoparietal areas encode representations of observed actions and corresponding written sentences in an overlapping way, but these representations did not generalize across stimulus type. By contrast, only left lateral posterior temporal Cortex (LPTC) encoded action representations that generalize across observed action scenes and sentences. The representational organization of stimulus-general action information in LPTC could be predicted from models that describe basic agent-patient relations (object- and person-directedness) and the general semantic similarity between actions. The match between action videos and sentences in LPTC and its representational profile indicate that this region encodes general, conceptual aspects of actions whereas Frontoparietal representations appear to be tied to specific stimulus types.
