Somatostatinergic systems: an update on brain functions in normal and pathological aging

Martel, Guillaume; Dutar, P.; Epelbaum, Jacques; Viollet, Cécile

doi:10.3389/fendo.2012.00154

Cited by 74 publications

(73 citation statements)

References 196 publications

(240 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It includes Martinotti cells, which form axonal arbors on the tuft dendrites of neighbouring pyramidal cells. They are involved in the regulation of a wide range of processes (Martel et al, 2012). Neurons of both classes are widely distributed throughout all regions of mammalian cortex, and together they comprise a substantial proportion of all inhibitory interneurons (Martel et al, 2012;Rudy et al, 2011).…”

Section: Modulation That Suppresses Responses To Rf Inputmentioning

confidence: 99%

On the functions, mechanisms, and malfunctions of intracortical contextual modulation

Phillips

Clark

Silverstein

2015

Neuroscience & Biobehavioral Reviews

View full text Add to dashboard Cite

A broad neuron-centric conception of contextual modulation is reviewed and re-assessed in the light of recent neurobiological studies of amplification, suppression, and synchronization. Behavioural and computational studies of perceptual and higher cognitive functions that depend on these processes are outlined, and evidence that those functions and their neuronal mechanisms are impaired in schizophrenia is summarized. Finally, we compare and assess the long-term biological functions of contextual modulation at the level of computational theory as formalized by the theories of coherent infomax and free energy reduction. We conclude that those theories, together with the many empirical findings reviewed, show how contextual modulation at the neuronal level enables the cortex to flexibly adapt the use of its knowledge to current circumstances by amplifying and grouping relevant activities and by suppressing irrelevant activities.

show abstract

Section: Modulation That Suppresses Responses To Rf Inputmentioning

confidence: 99%

On the functions, mechanisms, and malfunctions of intracortical contextual modulation

Phillips

Clark

Silverstein

2015

Neuroscience & Biobehavioral Reviews

View full text Add to dashboard Cite

show abstract

“…The lowering of intracellular cAMP and Ca 2C concentrations is the most relevant mechanism for the inhibition of hormone secretion from endocrine cells, whereas the activation of PTP and MAPKs is postulated to play a role in the antiproliferative effect on tumor cells (Olias et al 2004). At the level of the CNS, SS is known to be a neuromodulator of many processes including sleep, sensory and motor activities, and cognitive functions (Martel et al 2012). Hypothalamic SS1 plays a key role in the control of pituitary hormone release.…”

Section: Ss-ergic Systemsmentioning

confidence: 99%

“…It is mostly found in non-glutamatergic cells where it generally co-localizes with g-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the brain (Martel et al 2012). SS1 functions as a neuromodulator that mainly acts at the presynaptic level.…”

Section: Uts2r5mentioning

confidence: 99%

MOLECULAR EVOLUTION OF GPCRS: Somatostatin/urotensin II receptors

Tostivint¹,

Daza²,

Bergqvist³

et al. 2014

Journal of Molecular Endocrinology

View full text Add to dashboard Cite

Somatostatin (SS) and urotensin II (UII) are members of two families of structurally related neuropeptides present in all vertebrates. They exert a large array of biological activities that are mediated by two families of G-protein-coupled receptors called SSTR and UTS2R respectively. It is proposed that the two families of peptides as well as those of their receptors probably derive from a single ancestral ligand-receptor pair. This pair had already been duplicated before the emergence of vertebrates to generate one SS peptide with two receptors and one UII peptide with one receptor. Thereafter, each family expanded in the three whole-genome duplications (1R, 2R, and 3R) that occurred during the evolution of vertebrates, whereupon some local duplications and gene losses occurred. Following the 2R event, the vertebrate ancestor is deduced to have possessed three SS (SS1, SS2, and SS5) and six SSTR (SSTR1-6) genes, on the one hand, and four UII (UII, URP, URP1, and URP2) and five UTS2R (UTS2R1-5) genes, on the other hand. In the teleost lineage, all these have been preserved with the exception of SSTR4. Moreover, several additional genes have been gained through the 3R event, such as SS4 and a second copy of the UII, SSTR2, SSTR3, and SSTR5 genes, and through local duplications, such as SS3. In mammals, all the genes of the SSTR family have been preserved, with the exception of SSTR6. In contrast, for the other families, extensive gene losses occurred, as only the SS1, SS2, UII, and URP genes and one UTS2R gene are still present.

show abstract

“…These age-related reductions can have functional consequences in the old brain because these neuropeptides are widely expressed in CNS and have important roles in the regulation of emotions, cognitive functions, and feeding behavior (Wettstein et al 1995;Thorsell et al 2006;Martel et al 2012). Interestingly, this old-onset caloric restriction model was capable to maintain the total number of NPY-IR and SS-IR neurons in the dentate hilus and hippocampus proper, showing that moderate caloric restriction was able to prevent the reduction of their levels, generally associated with the aging process.…”

Section: Discussionmentioning

confidence: 99%

Old-onset caloric restriction effects on neuropeptide Y- and somatostatin-containing neurons and on cholinergic varicosities in the rat hippocampal formation

Cardoso

Silva

Magano

et al. 2014

AGE

View full text Add to dashboard Cite

Caloric restriction is able to delay age-related neurodegenerative diseases and cognitive impairment. In this study, we analyzed the effects of old-onset caloric restriction that started at 18 months of age, in the number of neuropeptide Y (NPY)-and somatostatin (SS)-containing neurons of the hippocampal formation. Knowing that these neuropeptidergic systems seem to be dependent of the cholinergic system, we also analyzed the number of cholinergic varicosities. Animals with 6 months of age (adult controls) and with 18 months of age were used. The animals aged 18 months were randomly assigned to controls or to caloric-restricted groups. Adult and old control rats were maintained in the ad libitum regimen during 6 months. Caloric-restricted rats were fed, during 6 months, with 60 % of the amount of food consumed by controls. We found that aging induced a reduction of the total number of NPY-and SS-positive neurons in the hippocampal formation accompanied by a decrease of the cholinergic varicosities. Conversely, the 24-month-oldonset caloric-restricted animals maintained the number of those peptidergic neurons and the density of the cholinergic varicosities similar to the 12-month control rats. These results suggest that the aging-associated reduction of these neuropeptide-expressing neurons is not due to neuronal loss and may be dependent of the cholinergic system. More importantly, caloric restriction has beneficial effects in the NPY-and SS-expressing neurons and in the cholinergic system, even when applied in old age.

show abstract

Somatostatinergic systems: an update on brain functions in normal and pathological aging

Cited by 74 publications

References 196 publications

On the functions, mechanisms, and malfunctions of intracortical contextual modulation

On the functions, mechanisms, and malfunctions of intracortical contextual modulation

MOLECULAR EVOLUTION OF GPCRS: Somatostatin/urotensin II receptors

Old-onset caloric restriction effects on neuropeptide Y- and somatostatin-containing neurons and on cholinergic varicosities in the rat hippocampal formation

Contact Info

Product

Resources

About