Intrahippocampal insulin improves memory in a passive-avoidance task in male wistar rats

Babri, Shirin; Badie, Hamid Gholamipour; Khamenei, Saeed; Seyedlar, Mehdi Ordikhani

doi:10.1016/j.bandc.2007.01.002

Cited by 60 publications

(45 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our recent findings in rodents that IGF2, injected into the hippocampus or systemically, can significantly and persistently enhance the retention of hippocampal-dependent memories (Chen et al 2011;Stern et al 2014) led us to investigate and compare the role of IGF2, IGF1, or insulin injected intracerebrally in either the hippocampus or amygdala on hippocampal-and amygdaladependent tasks. Here we report that whereas a single injection of IGF1 has no effects on any of the memories investigated, regardless of the brain region in which it was injected into, insulin leads, as also suggested by previous studies (Park et al 2000;Babri et al 2007), to memory enhancement when injected into the hippocampus. However, we found the effect of insulin to be transient.…”

Section: Discussionsupporting

confidence: 87%

“…In agreement with previous reports (Park et al 2000;Babri et al 2007), we found that a two-way ANOVA followed by a Bonferroni post hoc test revealed a significant effect of insulin, compared with vehicle, in enhancing IA memory at a test given 24 h after IA training (significant treatment effect: F (1,24) ¼ 5.73, P ¼ 0.02; no test effect: F (1,24) ¼ 0.82, P ¼ 0.37; no interaction effect: F (1,24) ¼ 2.56, P ¼ 0.12; post hoc: Veh vs. insulin [Test 1]: P , 0.05). However, when memory was retested 7 d after training, the effect did not persist, indicating that insulin-mediated memory enhancement is transient ( Fig.…”

Section: Insulin Injected Into the Hippocampus Transiently Enhances Hsupporting

confidence: 94%

“…Studies in rodents showed that an intracerebroventricular injection of insulin immediately after inhibitory avoidance (IA) training leads to memory enhancement 24 h after training (Park et al 2000;Babri et al 2007) and that intracerebroventricular or hippocampal injection of insulin enhances spatial working memory and water maze memory (Moosavi et al 2006;Haj-ali et al 2009;McNay et al 2010). To our knowledge, there is no report thus far on the role of IGF1 on memory retention and performance; however, beneficial effects of exercise and recovery from brain insult or neurodegeneration have been shown to involve IGF1, possibly acting through neurogenesis (Aberg et al 2000;Carro et al 2001).…”

mentioning

confidence: 99%

See 2 more Smart Citations

The effect of insulin and insulin-like growth factors on hippocampus- and amygdala-dependent long-term memory formation

2014

View full text Add to dashboard Cite

Recent work has reported that the insulin-like growth factor 2 (IGF2) promotes memory enhancement. Furthermore, impaired insulin or IGF1 functions have been suggested to play a role in the pathogenesis of neurodegeneration and cognitive impairments, hence implicating the insulin/IGF system as an important target for cognitive enhancement and/or the development of novel treatments against cognitive disorders. Here, we tested the effect of intracerebral injections of IGF1, IGF2, or insulin on memory consolidation and persistence in rats. We found that a bilateral injection of insulin into the dorsal hippocampus transiently enhances hippocampal-dependent memory and an injection of IGF1 has no effect. None of the three peptides injected into the amygdala affected memories critically engaging this region. Together with previous data on IGF2, these results indicate that IGF2 produces the most potent and persistent effect as a memory enhancer on hippocampal-dependent memories. We suggest that the memory-enhancing effects of insulin and IGF2 are likely mediated by distinct mechanisms.

show abstract

Section: Discussionsupporting

confidence: 87%

Section: Insulin Injected Into the Hippocampus Transiently Enhances Hsupporting

confidence: 94%

mentioning

confidence: 99%

See 1 more Smart Citation

The effect of insulin and insulin-like growth factors on hippocampus- and amygdala-dependent long-term memory formation

2014

View full text Add to dashboard Cite

show abstract

“…The patency of the guide cannulas was maintained with dummy cannulas. The rats were allowed to recover from surgery for 7 d. VGF (4 g in 2 l) or saline was delivered manually by a Hamilton syringe connected to a 28 gauge internal cannula, which protruded slightly beyond the guide cannula, and the injection cannula was left in place for 1 min after delivery to allow for diffusion of the neuropeptide (Babri et al, 2007). VGF was infused daily for 7 d and the animals were weighed every day at the time of injection.…”

Section: Sds-page and Western Blot Analysismentioning

confidence: 99%

The Neuropeptide VGF Produces Antidepressant-Like Behavioral Effects and Enhances Proliferation in the Hippocampus

Krol²,

et al. 2007

View full text Add to dashboard Cite

Brain-derived neurotrophic factor (BDNF) is upregulated in the hippocampus by antidepressant treatments, and BDNF produces antidepressant-like effects in behavioral models of depression. In our previous work, we identified genes induced by BDNF and defined their specific roles in hippocampal neuronal development and plasticity. To identify genes downstream of BDNF that may play roles in psychiatric disorders, we examined a subset of BDNF-induced genes also regulated by 5-HT (serotonin), which includes the neuropeptide VGF (nonacronymic). To explore the function of VGF in depression, we first investigated the expression of the neuropeptide in animal models of depression. VGF was downregulated in the hippocampus after both the learned helplessness and forced swim test (FST) paradigms. Conversely, VGF infusion in the hippocampus of mice subjected to FST reduced the time spent immobile for up to 6 d, thus demonstrating a novel role for VGF as an antidepressant-like agent. Recent evidence indicates that chronic treatment of rodents with antidepressants increases neurogenesis in the adult dentate gyrus and that neurogenesis is required for the behavioral effects of antidepressants. Our studies using

show abstract

“…Babri et al (1) showed that intra-hippocampal injections of insulin enhance memory. This supports that insulin plays an important role in memory formation.…”

Section: Discussionmentioning

confidence: 99%

Intranasal insulin treatment improves memory and learning in a rat amyloid-beta model of Alzheimer’s disease

Farzampour¹,

Majdi²,

Sadigh-Eteghad³

2016

Physiology International

View full text Add to dashboard Cite

Recently, insulin has been used as a pro-cognitive agent for the potential treatment of Alzheimer's disease (AD), because of its ability to cross the brain-blood barrier (BBB) by a saturable transport system. This study has been designed to evaluate the effects of intranasal insulin regimen, as a bypass system of BBB, on spatial memory in amyloid-beta (Aβ) model of AD in rat. Unilateral infusion of Aβ 25-35 (10 nmol/2 μl/rat) into the lateral ventricular region of brain was used to produce a rat model of AD. After a 24-h recovery period, rats received insulin or vehicle via intraperitoneal or intranasal route (0.1, 0.2, and 0.3 IU) for 14 days. Memory function in rats was assessed by Morris water maze test, with 5 days of training and consequent probe test protocol. Different doses of intraperitoneal insulin did not have a significant effect on learning and memory in AD rats. However, intranasal insulin at doses of 0.2 and 0.3 IU improved the learning and memory in Aβ-received rats.In conclusion, intranasal insulin as a non-invasive strategy improves spatial learning and memory in AD model.

show abstract

Intrahippocampal insulin improves memory in a passive-avoidance task in male wistar rats

Cited by 60 publications

References 53 publications

The effect of insulin and insulin-like growth factors on hippocampus- and amygdala-dependent long-term memory formation

The effect of insulin and insulin-like growth factors on hippocampus- and amygdala-dependent long-term memory formation

The Neuropeptide VGF Produces Antidepressant-Like Behavioral Effects and Enhances Proliferation in the Hippocampus

Intranasal insulin treatment improves memory and learning in a rat amyloid-beta model of Alzheimer’s disease

Contact Info

Product

Resources

About