Glutamate: its role in learning, memory, and the aging brain

Abstract

L-Glutamate is the most abundant of a group of endogenous amino acids in the mammalian central nervous system which presumably function as excitatory neurotransmitters and under abnormal conditions may behave as neurotoxins. As neurotransmitters, these compounds are thought to play an important role in functions of learning and memory. As neurotoxins, they are believed to be involved in the pathogenesis of a variety of neurodegenerative disorders in which cognition is impaired. Moreover, brain structures which are considered anatomical substrata for learning and memory may be particularly vulnerable to the neurotoxic actions of these excitatory amino acids, especially in the elderly who are also the segment of the population most susceptible to impairments of mnemonic function. This paper is a review of data concerning the role of excitatory amino acids in the processes of learning and memory and in the pathogenesis and treatment of disorders thereof.

A Behavioral Analysis of the Spatial Learning Deficit Induced by the NMDA Receptor Antagonist MK-801 (Dizocilpine) in the Rat

“…A number of studies during the past decade have suggested a critical role of glutamatergic N-methyl-D-aspartate (NMDA) receptors in learning and memory processes (McEntee and Crook 1993;Rison and Stanton 1995). Induction of hippocampal long-term potentiation (LTP), a cellular model of neural plasticity (Bliss and Lomo 1973), has been shown to require the activation of NMDA receptors.…”

Chemical composition, phytochemical analysis and antimicrobial activity of Boerhavia procumbens

“…Glutamic and aspartic acids are used in higher concentration for the stimulation of brain activities and maintain the cognitive functions of the brain (Leon, 1986;McEntee and Crook, 1993). In this study, the aspartic acid and glutamic acid are recorded in higher amount in the roots and stem.…”

A glutamic acid-based polymer keeping intact the integrity of all the three original functionalities of the amino acid

“…Figure 5vii-ix). The zwitterionic dipole has an overall excess negative charge by virtue of more effective binding of the N + by Cl -than the binding of CO 2 − by Na + . The repulsion among the dipole centers with excess negative charges leads to increasing viscosity with increasing NaCl concentration.…”

“…The apparent basicity constants of anionic centers are described by equation 3, where log K i o = pH at α = 0.5 and n i = 1 in the case of sharp basicity constants. In salt-free water, basicity constants log K 1 of the amine group in (=) 8, which is the pK 1 of its conjugate acid (±−) 7, and log K 2 of the terminal CO 2 − in (±−) 7 (i.e. pK 2 of its conjugate acid in (±) 6) were determined to be 10.94 and 5.25, respectively, in salt-free water (Table 2) and 9.94 and 4.56 in1 M NaCl.…”

“…Its salt, known as glutamate, one of the most abundant molecules in the brain, is an important neurotransmitter in neural activation. [1] Glutamate is involved in cognitive functions such as learning and memory in the brain [2] and a key compound in cellular metabolism. [3] Free glutamic acid, present in a wide variety of foods, is responsible for umami, one of the five basic taste of the human sense of taste.…”