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).