+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Ventral hippocampal alpha4beta2 nicotinic receptors and chronic nicotine effects on memory

Ventral hippocampal alpha4beta2 nicotinic receptors and chronic nicotine effects on memory

Neuropharmacology 39(13): 2770-2778

Chronic nicotine administration has been repeatedly shown to facilitate working memory function in rats on the radial-arm maze. The critical neural mechanisms for this effect are still being discovered. The nicotinic nature of the chronic nicotine induced memory improvement is supported by the finding that it is blocked by chronic mecamylamine co-infusion. The hippocampus also appears to be critically important. Hippocampal ibotenic acid lesions block the effect. Within the hippocampus, we have found that the alpha4beta2 nicotinic receptor subtype is involved in memory functioning. Acute ventral hippocampal infusions of the alpha4beta2 nicotinic antagonist dihydro-beta-erythroidine (DHbetaE) significantly decreased working memory performance in the radial-arm maze. The aim of the current study was to determine the importance of alpha4beta2 receptors within the ventral hippocampus for the memory enhancing effects of chronic nicotine treatment. Adult female Sprague-Dawley rats were trained on the 8-arm radial maze and were cannulated bilaterally in the ventral hippocampus. Osmotic minipumps administering chronic nicotine at a rate of 5 mg per kg per day were also implanted in the nicotine treatment rats. Control rats received saline-only minipumps. For a period of 4 weeks after surgery, each rat received bilateral hippocampal infusions of 0, 2, 6 and 18 microg per side of DHbetaE and tested for memory performance on the radial-arm maze. Radial-arm maze choice accuracy was impaired by acute hippocampal DHbetaE infusion in a dose-related fashion. This acute hippocampal DHbetaE-induced choice accuracy impairment was eliminated by chronic systemic nicotine infusion. Chronic nicotine in combination with acute vehicle hippocampal infusion was not seen to alter choice accuracy. Response latency was not found to be altered by acute hippocampal DHbetaE in the absence of chronic nicotine administration, but it did attenuate the response latency reduction induced by chronic nicotine infusion. Wet dog shakes were not found to be affected by hippocampal DHbetaE when given without chronic nicotine. Wet dog shakes were significantly increased by chronic nicotine infusion. Intra-hippocampal DHbetaE significantly potentiated this effect. The results from the current study reinforce the hypothesis that ventral hippocampal alpha4beta2 nicotinic receptors are important for memory function. These receptors may also have a role to play in the development of other aspects of behavior associated with chronic nicotine treatment.

Please choose payment method:

(PDF emailed within 1 workday: $29.90)

Accession: 011638414

Download citation: RISBibTeXText

PMID: 11044746

Related references

Chronic inhibition of Rho kinase blunts the process of left ventricular hypertrophy leading to cardiac contractile dysfunction in hypertension-induced heart failure. Journal of Molecular and Cellular Cardiology 35(1): 59-70, 2003

Ventral hernias. A big "minor" problem. Ugeskrift for Laeger 160(7): 983, 1998

Comparative effects of chick ADF and chick cofilin on actin filament turnover. Molecular Biology of the Cell 10(Suppl. ): 157a, 1999

Nicotine promotes proliferation and cfos induction in bone cells-The effects of smoking on skeletal repair and remodeling. Journal of Bone and Mineral Research 14(Suppl. 1): S477, 1999

Dorsal hand coverage with free serratus fascia flap. Journal of Reconstructive Microsurgery 19(8): 555-559, 2003

Virally mediated expression of a dominant negative TrkB receptor in the amygdala impairs fear conditioning. Society for Neuroscience Abstract Viewer and Itinerary Planner : Abstract No 292 23, 2003

Nicotine effects and the endogenous opioid system. Journal of Pharmacological Sciences 125(2): 117-124, 2014

Chronic nicotine restores normal Aβ levels and prevents short-term memory and E-LTP impairment in Aβ rat model of Alzheimer's disease. Neurobiology of Aging 32(5): 834-844, 2011

Upregulation of superoxide dismutase and nitric oxide synthase mediates the apoptosis-suppressive effects of shear stress on endothelial cells. Arteriosclerosis Thrombosis and Vascular Biology 19(3): 656-664, 1999

Changes in confocal indocyanine green angiography through two years after photodynamic therapy with verteporfin. Ophthalmology 110(7): 1306-1314, 2003

Effects of cycloartocarpin A and artocarpin extracted from Fructus Artocarpi Heterophylli on apoptosis of SMMC-7721 and SGC-7901 cells. Journal Of Chinese Integrative Medicine: 1, 61-66, 2010

Chronic alpha-tocopherol administration protects against behavioral impairments induced following intrahippocampal aggregated Abeta injections. Society for Neuroscience Abstracts 26(1-2): Abstract No -664 2, 2000

Chronic treatment of human astrocytoma cells with lithium, carbamazepine or valproic acid decreases inositol uptake at high inositol concentrations but increases it at low inositol concentrations. Brain Research 855(1): 158-161, 2000

Comparison of nicardipine versus placebo to control hemodynamic responses to emergence and extubation. Anesthesiology 91(3A): A156, 1999