The Influences Of Ketamine On The Expression Of GAP-43 And Synaptophysin In SD Infant Rat Hippocampl Neuronal

Background and objective :The period of brain growth spurt (BGS) starts with the last trimester of pregnancy in humans and continues until about 2 years after birth. In rats , the corresponding period is encompassed by the first 3 weeks after birth, and is characterised by a rapid increase in brain weight, proliferation of astroglial and oligodendroglial cells, neuronal axonal elongation, dendritic arborization and synaptogenesis,the synaptic plasticity plays an essential role in this process. N-methyl- D-aspartate(NMDA) receptors play a critical role in brain development, provides trophic functions in the developing brain, by influencing synaptic plasticity, and promoting proliferation and migration of neuronal progenitors. Recently, it was shown that a transient blockade of glutamate NMDA receptors during the period of BGS induced potentiation of apoptosis in the different regional of brain. Physiological apoptosis (programmed cell death) is a naturally occurring process of the developing brain . Whether or not alterations of the process occur by blockade of NMDA receptors during early, mid or late stages of the BGS will determine the configuration of neuronal death with consequences for developmental mechanisms of neuronal circuitry and, eventually the expression of neurobehavioral disorders. At present, several studies have indicated deficits in spatial learning, taste aversion learning and taste recognition memory tasks induced neonatally by NMDA antagonists. Learning and memory are important aspects of cognitive function, while the synaptic plasticity plays an essential role in this process . Growth-associated protein-43 (GAP-43), functions in axonal growth, synaptogenesis, synaptic remodeling, and neurotr- ansmitter release,published data suggest that GAP-43 also influences neuron survival ,the nervous system of mice and rat lacking the GAP-43 is rarely survive to weaning. Synaptophysin is a 38-kDa calciumbinding glycoprotein found in the membranes of neurotransmitter-containing presynaptic vesicles and is used as a specific protein marker for the presynaptic terminal. The level of synaptophysin protein is used as an index of...