Low-dose intranasal insulin improves cognitive function and suppresses the development of epilepsy.

Abstract

Intranasal insulin exerts neuroprotective effects in a variety of neurological diseases. Whether intranasal insulin affects epileptic activity and whether it has neuroprotective effects in epileptic diseases is however still unknown. In this study we show that low-dose intranasal insulin inhibited kainic acid (KA)- or pentylenetetrazole (PTZ)-induced acute seizures and reduced epileptic discharge activities in mice, potentially by alleviating the increase in seizure-induced glutamate in the hippocampus. Meanwhile, intranasal insulin increased GABA levels and the activities of hippocampal theta, which may affect the excitability of the hippocampus. In chronic KA-induced epilepsy, low-dose intranasal insulin reduces the frequency of spontaneous recurrent seizures and epileptic discharges, while it increases theta energy and thereby improves spatial memory. Larger doses of intranasal insulin increased the frequency of seizures but did not aggravate cognitive impairment, suggesting that the frequency of seizures may not be related to impaired cognitive function. Overall, our findings show that low-dose intranasal insulin inhibits epileptic events and improves cognitive impairment in epileptic mice, suggesting that learning and memory can be improved by intranasal insulin. However, larger doses might increase the risk of epileptic seizures.

• Authors: Shu Peng, Jin Yang, Yufeng Wang, Yang Fan, Feng Tang, Changyue Hou, Juming Yu, Xiaoming Wang, Guohui Jiang
• Journal: Brain research (Brain Res) Vol. 1726 Pg. 146474 (01 01 2020) ISSN: 1872-6240 [Electronic] Netherlands
• PMID: 31557476 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2019 Elsevier B.V. All rights reserved.

Chemical References

• Anticonvulsants
• Insulin
• Kainic Acid
• Pentylenetetrazole

Topics

• Administration, Intranasal
• Animals
• Anticonvulsants (administration & dosage)
• Brain (drug effects, physiopathology)
• Cognition (drug effects)
• Epilepsy (chemically induced, prevention & control, psychology)
• Insulin (administration & dosage)
• Kainic Acid (administration & dosage)
• Male
• Mice, Inbred C57BL
• Pentylenetetrazole (administration & dosage)
• Seizures (chemically induced, prevention & control, psychology)