Effects of single and continuous administration of amyloid β-peptide (25–35) on adenylyl cyclase activity and the somatostatinergic system in the rat frontal and parietal cortex

Hervás-Aguilar, América; Puebla‐Jiménez, L.; Burgos‐Ramos, Emma; Aguado-Llera, David; Arilla‐Ferreiro, Eduardo

doi:10.1016/j.neuroscience.2005.02.017

Cited by 16 publications

(10 citation statements)

References 75 publications

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“…The equilibrium parameters of the Sst as well as the protein levels of sst1-4 in the hippocampus of control rats were similar to those previously reported by our group and other authors Hervás-Aguilar et al, 2005;Epelbaum et al, 1982;Srikant and Patel, 1981). In the present study, the depletion of hippocampal SS-LI levels in rats fed a VA-free diet was accompanied by an increase of SS binding concomitant with an increase in the protein levels of sst (1-4).…”

Section: Discussionsupporting

confidence: 92%

A vitamin A-free diet results in impairment of the rat hippocampal somatostatinergic system

2006

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Abstract-Previous studies have revealed the presence of retinoid specific receptors in the hippocampus and have demonstrated that vitamin A deficiency produces a severe deficit in spatial learning and memory which are linked to a proper hippocampal functioning. It is also well known that the tetradecapeptide somatostatin binds to specific receptors in the hippocampus and, when injected into this brain area, facilitates the acquisition of spatial tasks. In addition, depletion of somatostatin by cysteamine impairs acquisition of these tasks. Taken together, these studies support the idea that the hippocampal somatostatinergic system might be regulated by vitamin A. Hence, we evaluated the effects of vitamin A deprivation and subsequent administration of vitamin A on the rat hippocampal somatostatinergic system. Rats fed a vitamin A-free diet exhibited a significant reduction of somatostatin-like immunoreactivity content in the hippocampus whereas the somatostatin mRNA levels were unaltered. Vitamin A deficiency increased the somatostatin receptor density and its dissociation constant. Functional Gi activity as well as the capacity of somatostatin to inhibit basal and forskolin-stimulated adenylyl cyclase activity was decreased in vitamin A deficiency rats as compared with the control animals. All these parameters were fully restored when vitamin A was replaced in the diet. Furthermore, we found that the Gi␣ 1 , Gi␣ 2 and Gi␣ 3 protein levels were unaltered in hippocampal membranes from rats fed a vitamin A-free diet whereas subsequent vitamin A administration to these rats caused a significant increase in the levels of Gi␣1 and Gi␣2. Altogether, the present findings suggest that dietary vitamin A levels modulate the somatostatinergic system in the rat hippocampus.

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Section: Discussionsupporting

confidence: 92%

A vitamin A-free diet results in impairment of the rat hippocampal somatostatinergic system

2006

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“…One of the principal components of senile plaques is A␤, which is considered to be involved in the pathogenesis of AD (Hsiao et al, 1996;Selkoe, 2001). Our group has recently shown that chronic A␤ (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) infusion, an animal model of AD, decreases sst density and expression in the rat frontoparietal cortex (Hervás-Aguilar et al, 2005) and temporal cortex , an effect accompanied by decreased receptor functionality.…”

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confidence: 99%

“…In addition, Hunter et al (2004), using an experimental model of AD in mice, have documented that minocycline reduces the magnitude of cholinergic fiber loss in the hippocampus and attenuates cognitive impairment. To date, however, it is unknown whether minocycline can protect the SRIF receptor-effector system from alterations present in the AD brain and after chronic A␤ infusion Hervás-Aguilar et al, 2005). To address this issue, we examined the effects of minocycline on: 125 I-Tyr 11 -SRIF binding to SRIF receptors, sst1-sst4 protein expression, sst mRNA levels, phosphorylated and total cyclic AMP (cAMP) response element binding protein (CREB) content, basal and stimulated AC activity, SRIF-induced inhibition of AC activity and Gi␣1-Gi␣3 protein levels in the temporal cortex of control and A␤(25-35)-treated rats.…”

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confidence: 99%

Minocycline provides protection against β-amyloid(25-35)-induced alterations of the somatostatin signaling pathway in the rat temporal cortex

2008

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“…infusion of Aβ1-40 or Aβ25-35 for 14 days resulted in significant reductions in SLI content in the rat hippocampus, frontoparietal cortex and temporal cortex [117][118][119][120], which parallels the reduction seen in postmortem brains of patients with AD [105]. The treatment of such rats with IGF-1 [119] or estradiol [121] partially restored the SST parameters affected after Aβ infusion.…”

Section: Alzheimer's Diseasementioning

confidence: 64%

Somatostatin and Cognitive Function in Neurodegenerative Disorders

Tuboly¹,

Vécsei

2012

MRMC

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During the past 40 years, somatostatin (SST) has been a subject of intensive research.Apart from its substantial role in the neuroendocrine system, due to its dense localization in various areas in the brain, its functions as a neuromodulator have also been thoroughly investigated. Increasing evidence suggests that SST plays a crucial role in memory and cognition. Synthetic forms, biologically active peptide sequences, SST receptor agonists and SST depleting agents have been applied in animal models and in human studies of a number of neuropsychiatric disorders. The translation of experimental data into clinical use could provide novel therapies in neurodegenerative disorders involving cognitive dysfunctions. However in view of the controversial data reported concerning the different roles of the SST receptor subtypes, and the lack of SST analogues that are able to cross diffusion barriers and act selectively at these receptor subtypes, broader clinical use of SST analogues as cognitive enhancers is limited. This review covers the whole range of available experimental results relating to the behavioural effects of SST, and highlights the potential for further investigations.

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Effects of single and continuous administration of amyloid β-peptide (25–35) on adenylyl cyclase activity and the somatostatinergic system in the rat frontal and parietal cortex

Cited by 16 publications

References 75 publications

A vitamin A-free diet results in impairment of the rat hippocampal somatostatinergic system

A vitamin A-free diet results in impairment of the rat hippocampal somatostatinergic system

Minocycline provides protection against β-amyloid(25-35)-induced alterations of the somatostatin signaling pathway in the rat temporal cortex

Somatostatin and Cognitive Function in Neurodegenerative Disorders

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