Pathophysiology 17 (2010) 39–44 Effect of acute and chronic hypertension on short- and long-term spatial and avoidance memory in male rats Gholam Reza Ghavipanjeh a , Hojjatllah Alaei a,∗ , Majid Khazaei a , Ali Asghar Pourshanazari b , Reihaneh Hoveida c a Department of Physiology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran b Department of Physiology, Faculty of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran c Department of Biology, Faculty of Science, Islamic Azad University of Dourod, Dourod, Lorestan, Iran Received 23 April 2009; received in revised form 28 June 2009; accepted 9 July 2009 Abstract It has been demonstrated that hypertension can lead to coronary heart disease, heart failure, stroke, and memory loss. In this study we investigated the effect of acute and chronic hypertension on the avoidance and spatial learning and memory in rats. The forty male rats were divided into acute hypertensive, chronic hypertensive and control for each group rats. Hypertension was induced by Deoxy Corticosterone Acetate (DOCA)-salt method. DOCA was injected 30mg/kg of body weight subcutaneously, twice a week. These rats received NaCl 1% instead of tap water for drinking throughout the experiment. The control group received normal saline injection with usual drinking water. Spatial learning and memory was investigated by Morris water maze test and passive avoidance learning by Shuttle box test in the rats after hypertension induction. Results showed that acute hypertension impaired short-term memory in passive avoidance learning. However, acute and chronic hypertension did not affect spatial learning and memory. These data suggest that simple uncomplicated hypertension does not remarkably alter cognition. © 2009 Elsevier Ireland Ltd. All rights reserved. Keywords: Hypertension; Passive avoidance learning; Spatial memory; Rat 1. Introduction Hypertension occurs when the blood is under increased pressure, pushing against the walls of blood vessels. Blood pressure between 120 to 140/80 to 90 is “pre-hypertension” and over 140/90 is definite hypertension. Hypertension can lead to coronary heart disease, heart failure, stroke, kidney failure, and other problems such as memory loss [1]. Hypertension can damage to blood vessels by causing a build-up inside the blood vessels and making them narrow. The brain must have a certain amount of blood flow to work normally. If the amount of blood flow is less than it should Abbreviations: DOCA, Deoxy Corticosterone Acetate; SBP, systolic blood pressure; SHR, spontaneously hypertensive rats; ACE, angiotensin converting enzyme. ∗ Corresponding author. Tel.: +98 311 792 2407; fax: +98 311 668 7898. E-mail address: alaei@mrd.mui.ac.ir (H. Alaei). be, the brain cannot work efficiently. This can lead to mem- ory loss and other symptoms [2]. While in the early part of the 20th century clinicians believed that essential hyperten- sion was necessary for normal physiological function; more recent studies have clearly indicated the deleterious nature of chronic elevation of arterial pressure on many organ sys- tems. Nearly 30 years ago, data from Wilke and Eisdorfer suggested that hypertension may lead to memory impair- ments [3] and many subsequent reports have supported this relationship in humans [4–8]. Several additional studies sug- gest that high blood pressure contributes to cognitive deficits in aging individuals [9,10], but other research indicated that cognitive function gradually declines with age in humans, irrespective of arterial pressure [11,12] and that this age- related impairment extends to spatial learning and memory tasks [13,14]. Previous study also supported the hypothesis that high blood pressure (especially existent over an extended period of time) would be responsible for cognitive deteriora- 0928-4680/$ – see front matter © 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.pathophys.2009.07.002