Abstract
Phoenix dactylifera fruits possess essential properties such as analgesic, antioxidant, andnephroprotective activity but there is paucity of information on researches centered on the benefits of Phoenix dactylifera in learning and memory. This study was designed to evaluate the effects of Phoenix dactylifera fruit extract on spatial learning and memory using neurobehavioral paradigms of Morris water, Barnes, and elevated plus mazes as well as evaluation of acetylcholinesterase enzyme activity of the brain tissues of the mice studied. Seventy five mice of both sexes were used for the study and divided into five groups of 5 mice each. Group 1 (distilled water 10 ml/kg) served as control, group 5 (Piracetam 100 mg/kg) served as positive control. Groups 2-4 were treated withPhoenix dactylifera extract 1000, 500 and 250 mg/kg respectively. Treatment with aqueous extract of Phoenix dactylifera and Piracetam was done 1 hour prior to the experiment daily for three days (in Morris water and Barnes mazes) and two days (in elevated plus maze). Results obtained from this study revealed that Phoenix dactylifera fruit (1000 mg/kg) impaired learning of mice in Morris water maze (p<0 .05="" and="" barnes="" between="" but="" control="" did="" difference="" elevated="" group="" i="" impair="" in="" maze.="" maze="" memory="" morris="" no="" not="" plus="" seen="" significant="" statistically="" was="" water="">Phoenix dactylifera
treated groups in acetylcholinesterase activity in Morris water, Barnes and elevated plus mazes, but statistically significant difference exist between control group and Piracetam treated group in acetylcholinesterase activity (p>0.05). No strong correlation was observed between probe parameters of neurobehavioral paradigms (frequency of platform crossings, retention and correct head dips in Morris water, Barnes and elevated plus mazes respectively) and acetylcholinesterase activity. Acute treatment with aqueous extract of Phoenix dactylifera fruit impaired learning in Morris water maze and has no effect on memory in Morris water, Barnes and elevated plusmazes.
CHAPTER ONE
1.0 Introduction
One of the major functions of the brain is the flexible adaptation to our ever-changing environment. The brain possesses executive circuits which do not only monitor and maintain current behavioral goals but also incorporate new goals and rules. This updating can come in the form of a quick integration of previously acquired knowledge when a well-known stimulus informs an animal of a change in reward contingencies. Hence, such updating requires new learning.Higher cognitive abilities evolved largely in mammals (Victoria et al., 2014).
Cognitive neuroscientists consider memory as the retention, reactivation, and reconstruction of the experience-independent internal representation (Schwabe and Wolf, 2010). The major challenge of neuroscientists today is identifying therapies or mechanisms that can treat or reverse the effects of memory complaints and other neurodegenerative disorders. Date palm (known as Phoenix dactylifera) has been used intreatment of various nervous disorders and memory complaint (Vyawahare et al., 2009), such as Parkinson‘s disease via acting as dopamine agonist
(Ali et al., 2014), Alzheimer‘s and Vascular dementiavia its protective role in cerebral hypoperfusion (Rohini et al., 2014).
Brain areas involved in the neuroanatomy of memory include the hippocampus, the amygdala, the striatum, or the mammillary bodies which are thought to be involved in specific types of memory. For example, the hippocampus is believed to be involved in spatial learning and declarative learning, while the amygdala is thought to be involved in emotional memory (Labark and Cabeza, 2006). Prefrontal cortex and basal ganlia play vital role in storing working memory (Fiona and Torkel, 2008).
